Sound Practices Mailing List Files - Volume 1
=========================================================================
From: "Bottlehead" <Bottlehead@prodigy.net>
Subject: B-52s and Lowthers (long)
Date: Wed, 26 Nov 1997 09:06:24 -0800
Source: Sound Digest Archive v01.n120
>
> I had a pretty fair weekend myself. Took my 6SL7/46/VV52 amps over to a
> friend's house and hooked them up to a pair of ProAc Response 3s (!),
with
> a little help from his dedicated subwoofers. They didn't do badly at
all.
> Maxed out on Prokofiev, but of course I'm still only running the 52s at
80
> ma to accomodate the FS030s. Gotta get me some of Mikey's big fellas!
:-)
>
Yeah, Grover, burn them suckers, at least 450V 120 mA, more is probably
better. They should give you gobs of bottom end, like no other tube. I
thought that maybe the 52s could be run the same way as the 32s when I got
them (say 350V 70 mA), but they want to burn. They work wonders on my PM2As
on the bottom.
Mike says the RS-520 should be a killer OT, having been designed for the
52s, but I'm so hung up on parafeed that I haven't tried the combo yet.
Speaking of the Lowthers, some minor miracles took place this week.
Firstly I'd like to thank Mr. Uchida of Sun Audio for finally breaking them
PM2As in during VSAC. Secondly, here's my current recipe for PM2As in
Medallion cabs-
a) loan your drivers to someone else for 6 months. This will help you avoid
any (additional ) brain damage during the painful breakin period. The most
important thing about Lowthers is not to listen to them until they are
broken in. This may take up to a year. If you slip up and listen to them
during this period, don't blame me if you decide to sell them.
b) listen to the method, but not the madness, of other Lowther owners. By
this I mean, try general approaches, but ignore the exact details of how
much damping, where it goes, etc. This held me back for a year. My dear
friend Tony G. is as guilty of this as anyone. Ignore the phrase "It works
in my room."
c) through much diddling, here is my recipe. *Only consider this as a
starting point for your own situation, and remember that breakin is the
most important step*
Line the driver chamber back wall. Try either a Deflex pad or 1/4 to 3/8"
felt. I am using felt right now because I gave away the Deflex panels Jon
Ver Halen sent me, in a fit of compassion for another Lowther owner.
Line the bottom and rear angled baffle of the Medallion mouth with felt
too. This kills some standing wave biz, I think I measured 70, 140, 280 Hz
at some point in the past. Now, take 12, not 1, not "three, gently teased
out", not 1/2" weatherstrip foam, but 12 small cotton balls, and stuff that
goddamn gap between the whizzer and the main cone, so that the balls are
about 1/3 exposed. Don't tell me I'm killing the midrange, you bet I am,
with extreme prejudice. It needs the shit beat out of it, twice. Not only
does this cotton stuff the "horn" between the whizzer and cone that makes
the 2 khz peak, it damps the edge of the whizzer, which rings like a bell.
To do this right maybe you need to string the balls on thread, like Xmas
popcorn, but I just put the grill back on and the cloth does a fair job of
holding the balls in place, unless you pull out them drum CDs and run at
6-8 watts (my ears were ringing for a full day after that stupidity). As
far as I'm concerned, no clarity is lost in this operation. If you are a
long time Lowther owner you will possibly disagree that this gives flatter
midrange response, but I submit that your brain is fooling you. I get
tenacious headaches whenever I listen to Lowthers that are not damped in
some way.
After all this I ran a test record sweep, and I'll be damned if it didn't
sound very respectably flat from say 12 Khz to 100 Hz, with a minor peak
somewhere around 8 kHz. I was frankly amazed.
By the way that parafeed 45 amp shines with the Lowthers, but I am using
the 52 amp, while I revel in Way Too Loud for a while.
d) Many Lowther owners will say I am lying, no Lowther starts to roll of at
100Hz. And besides all that bass in other speakers is fake.
Are you people feeling OK? Go the the symphony once in a while! Listen to a
real tympani, tuba, double bass.
Yes a Lowther makes a little noise at 50 Hz, but who cares? It is many dB
down from the rest of the curve. Let's get real here folks.
d)Subwoofer.
Ok, so I have the Whamo bandpass box. Not quite as efficient, maybe 2-3 db
down, but good for 35 -100 Hz, no crossover.
So I put a pair of 25W 211 amps on the 96 dB subs, and about 10W of VV52 on
each Medallion.
Hey not perfect, the 211 amps are a bit mushy in the bass, and I'm not real
big on the out of phase back wave from the horn, a wee bit slow and hollow,
and yes the sub is wired out of phase to match. But this is pretty effing
good. Vocals are quite realistic on the 2As for the first time, the classic
Lowther mid and treble clarity is retained without the deadly peaks.
Saxophone is marvelous.
The presentation is good enough that this system will spell the Hyperwhamos
for a while, being cleaner in the mid and top, although not as clean in the
midbass and a bit less extended on top. It has also inspired some soon to
be done eXperimentation with PM2As and a not ready yet to be revealed
woofer combo, in new cabinets.
Let me finish here by saying that 35 wpc on this system (96-99 dB) is
almost enough....
Doc B., saying "Huh?"
=========================================================================
From: Grover Gardner <groverg@bellatlantic.net>
Subject: Re: B-52s and Lowthers (long)
Date: Wed, 26 Nov 1997 21:38:11 -0600
Source: Sound Digest Archive v01.n120
At 9:06 AM -0800 11/26/97, Bottlehead wrote:
>>
>> I had a pretty fair weekend myself. Took my 6SL7/46/VV52 amps over to a
>> friend's house and hooked them up to a pair of ProAc Response 3s (!),
>with
>> a little help from his dedicated subwoofers. They didn't do badly at
>all.
>> Maxed out on Prokofiev, but of course I'm still only running the 52s at
>80
>> ma to accomodate the FS030s. Gotta get me some of Mikey's big fellas!
>:-)
>>
>Yeah, Grover, burn them suckers, at least 450V 120 mA, more is probably
>better. They should give you gobs of bottom end, like no other tube. I
>thought that maybe the 52s could be run the same way as the 32s when I got
>them (say 350V 70 mA), but they want to burn. They work wonders on my PM2As
>on the bottom.
>Mike says the RS-520 should be a killer OT, having been designed for the
>52s, but I'm so hung up on parafeed that I haven't tried the combo yet.
Well, yeah! Get him to loosen up, fer chrissakes, and send me a pair for
free, huh? :-) Or get him to do a nice plate choke at 150ma/20H. Heck, at
600 Rp that's all the inductance I need, eh? Then I can keep my 030s!
Don't you love being talked about in the third person, Mike?! :-)
Seriously, I can't *wait* to get these guys up to speed, but even at 80ma
they are still sounding awfully good.
Grover Gardner
groverg@bellatlantic.net
=========================================================================
From: "Henry Pasternack" <hap@nortel.ca>
Subject: Baby Ongaku criticism.
Date: 21 Jan 1998 15:12 EST
Source: Sound Digest Archive v01.n167
A couple of people have written to me in private email and it seems
that my coments on Reichert's "It's not my amp" philosophy have been
mixed up with my feelings about the Wavelength Audio 2A3 amp. Let me
set the two issues straight.
With regard to the amplifiers I built, obviously they are not "Baby
Ongakus" in the strictest sense because I made some changes in parts
selection, power supply topology and layout. I'm aware that this kind
of amplifier is sensitive to all of these things and it's not my intent
to criticize Rankin, Garber, or Reps on the basis of the results I have
had with my own project. I was simply reporting for the interest of the
group's readers how I went about building my amps and how they sounded
to me in one particular listening test.
I realize that Reichert had nothing to do with the "Baby Ongaku"
design. I wished to address his remarks in the "Flesh and Blood"
article. Let me express myself a different way. These circuits
being so simple, it seems to me that people like Herb Reichert are
calling themselves designers and innovators on the basis of their
experiments with parts selection in implementations of classic
circuits. I find this to be overly prideful and disrespectful to
the truly brilliant and original engineers who actually dreamt up
and realized the technology decades ago.
As well, I would like to see some consistency if I am to take
these people as reliable sources of practical information. It is
no great thing to be changing one's mind all of time time. I do
not see the flavor-of-the-month phenomenon as evolution as much
as aimless wandering. For the past five years, I have tried to
put together a cohesive picture of how all of these tweaks fit
together, and I'm still largely in the dark. The bottom line:
I took Reichert's comments to mean, "You can build it your way,
but you'd be a fool not to do it my way." I didn't like that,
and felt he could have phrased himself differently. After all,
experimentation is part of the fun.
Finally, I can't seem to avoid controversy whenever I subscribe
to this list. I guess it's because I bottle up a lot of frustration
with all the silly bickering that goes on in audiophile circles.
And I have no discipline. Well, I'm not going to gang up on
anyone this time.
Meanwhile, what I really wanted was comments and criticisms on
the Nardi preamp circuit. Surely someone read the article...?
- -Henry
=========================================================================
From: dslagle@earthlink.net
Subject: Re: Baby Ongaku criticism.
Date: Wed, 21 Jan 1998 18:16:28 -0800 (PST)
Source: Sound Digest Archive v01.n167
>Henry opined as follows:
>
>>These circuits being so simple, it seems to me that people like Herb
>>Reichert >are calling themselves designers and innovators on the basis of
>>their
>>experiments with parts selection in implementations of classic
>>circuits. I find this to be overly prideful and disrespectful to
>>the truly brilliant and original engineers who actually dreamt up
>>and realized the technology decades ago.
>
I see it a bit diffrently.... are there any new circuits out there?? are
there any truly brilliant engineers out there designing completely original
tube circuits???
Take any brilliant amp out there, and break it apart, and i bet somewhere
someone has already done it.... i guess thats the rub working with 70 year
old technology.
I see a lot of people taking 3-4 old ideas and glueing them together to
make their new one.... but what is new??? and where the hell does one come
up with the idea that newer is better, or something needs to be engineered
to be better... better is better thats it.
there are a large # of people here who gladly take their old technology
since to us is sounds better than 99.9% of the wonderful engineering out
there today..
as for the whole voodoo thing, I see it a bit differently....
take an amp with a low part count such as the reichert flesh and blood it
is actually conceivable to go through part by part make swaps and learn,
and come up with opinions on what a particular part sounds like in that
circuit, so even if you don't like it the way herb designed it, you are
allowed to disagree...
get even simpler to the potato amp... it can be built with 10 parts,
including the PS... any swap you can hear... I guess its a poorly designed
circuit????
granted, certain parts will show a bigger difference than other when
swapped, but what are we taking about here??? take output transformers....
will a well designed circut make all outputs sound the same??? how about
the more complex the circuit?? In the case of the potato, it was the first
time i heard the difference between CC and metal film resistors (100 ohm
grid stopper) now the same swap (MF for CC) in the same position of a ST-70
(1K before the EL-34's) showed me no difference... so i guess the ST-70 is
a better design??? Geee could it be that the more parts there are, the
less each individual part matters?
herb is no engineer, rather an artist.... art can be anything... it makes
it oh sooo simple... engineers can argue anything to death and win on
paper... its their job.... an artist has one job... get a response ... it
can be good bad or indifferent, but it is based on emotion and nothing
else... how do you measure emotion??? I don't much care to measure
anything... engineering will show us functionality... and is great to tell
us if something will work, but beyond that???
I love voodoo... its something someone who barely knows ohms law can use
against the big bad engineers... herb gives all of us poor wannabees the
faith that it doesn't take a genius to build a good amp... he lays the
foundation with what he did... and tells us exactly how to do it... then
like a good mother... pushes us out of the nest and forces us to fly....
when given the option of the intimidating audio engineer who hawks his
product with tons of specs, or the voodoo artist, i'll take voodoo... it
gives me hope and lets me believe in my own opinions... the engineer gives
me reasons to look up the recommended components list.
i'm sure someday there will be a p-spice for audio with *voodoo* parts
selection, and what will that tell us??? nothing more than herb did in his
flesh & blood article... this is what I like!
dave
=========================================================================
From: tubesguy@mail.execpc.com (Patrick Currie)
Subject: Re: Baby Ongaku criticism.
Date: Wed, 21 Jan 1998 19:56:52 -0500
Source: Sound Digest Archive v01.n167
Henry opined as follows:
>These circuits being so simple, it seems to me that people like Herb
>Reichert >are calling themselves designers and innovators on the basis of
>their
>experiments with parts selection in implementations of classic
>circuits. I find this to be overly prideful and disrespectful to
>the truly brilliant and original engineers who actually dreamt up
>and realized the technology decades ago.
Well, yow. I don't know that Herb called himself either a designer or an
innovator. My read on the article, and, admittedly, I read at only the
32nd grade level, is that he presented an amplifier that he was fairly
happy with, and told everyone exactly how to build it to exactly duplicate
its sound. Just a guess, but a cascaded 6SN7 into a 300B, as simple as the
notion is, probably wasn't dreamt up and realized decades ago, or, if it
was, it was never made known to the world. SE triode amps for high-end
audio is, as Herb himself has pointed out, a relatively recent phenomenon,
and owes less to brilliant and original engineers than it does to
fun-loving experimenters, mostly from Japan.
> Finally, I can't seem to avoid controversy whenever I subscribe
>to this list. I guess it's because I bottle up a lot of frustration
>with all the silly bickering that goes on in audiophile circles.
Hmm, hasn't been much bickering here until the last few days. Of course,
this is anything but an "audiophile circle." :-) - Pat
Pat Currie (tubesguy@execpc.com)
=========================================================================
From: "Henry Pasternack" <hap@nortel.ca>
Subject: re:Re: Baby Ongaku criticism.
Date: 22 Jan 1998 12:53 EST
Source: Sound Digest Archive v01.n168
Pat Currie writes:
>Well, yow. I don't know that Herb called himself either a designer or an
>innovator. My read on the article, and, admittedly, I read at only the
>32nd grade level, is that he presented an amplifier that he was fairly
>happy with, and told everyone exactly how to build it to exactly duplicate
>its sound. Just a guess, but a cascaded 6SN7 into a 300B, as simple as the
>notion is, probably wasn't dreamt up and realized decades ago, or, if it
>was, it was never made known to the world. SE triode amps for high-end
>audio is, as Herb himself has pointed out, a relatively recent phenomenon,
>and owes less to brilliant and original engineers than it does to
>fun-loving experimenters, mostly from Japan.
Hmmm. Well, Herb Reichert has written a lot more than just that
one article. His letter to the Editor of "Stereophile" attacking
Scott Frankland was a good summary of his position, and revealing
of Herb's many misconceptions about the history of amplifier design
and his place in that history. It was also silly. As for RC coupled
single-ended hi-fi amplifiers, they certainly have been around for
decades, and well-known to the world. Finally, as clever as our
friends in Japan are, true brilliance was what it took to develop
the thermionic valve in the first place, and figure out the circuits
that are the basis of all contemporary tube amplifiers. That happened
long before many of us were born.
As someone wrote to me this morning in personal email, you don't
take a dyna amp, change out the resistors and capacitors, and claim
it's your design and not Hafler's. This isn't art. It's skilled
craftsmanship. I happen to agree twith Michael LaFevre that there
is great honor in being a craftsman. You just have to understand
that there is a difference between a master artist and a proficient
student. I understand that art students learn their craft by
copying the works of the masters. I imagine they also become
adept at varying the elements in order to render individualized
impressions of pre-existing works. But what is artistic genius?
I suppose it's coming up with a whole new way of expressing
subjective perception. I'm sorry, this is not what Herb Reichert
is doing.
Anyway, I do apologize for all this criticism. In terms of
keeping the technology and craft alive, and finding ways to
improve classic circuits with modern components, the work all
of you folks are doing is invaluable as well as great fun to
read about.
- -Henry
=========================================================================
From: "J. Gordon Rankin" <waudio@cinti.net>
Subject: Re: Baby Ongaku criticism.
Date: Fri, 23 Jan 98 08:32:23 -0500
Source: Sound Digest Archive v01.n168
Henry,
I am sorry to hear that your out was not consistent with the others who
have built and enjoyed the Baby-O, MQ2A3, Trumpet design. Even reviews
that appeared in Absolute Sound.
I classify any amplifier into thirds as design, part quality and
construction. Lets assume that your build quality was ok, this is only
one third the design for which was published.
If you read the Bugle article I am not too found of the 2A3, finding the
45 much better sonically matched to acceptable speakers. First though
lower wattage amplifiers require a choke loaded power supply because they
need the self regulation properties to function into complex loads in the
lower frequencies.
Three clairifactions on the circuit publised:
1) Don layout does not include the the resistor divider that puts the
filament voltage for the 12AT7 at the right point.
2) The power supply inductor that I have used for this design is a 15H
hammond unit at 75ma.
3) For the capacitor after the choke in the power supply I use a
100uF*2/500V Cerafine in parallel with a 20uF SCR across it making a
total effective cap of 220uF after the choke.
Henry, why not try it this way before you give up on it.
Gordon
=======> Wavelength Audio <=======
mailto:waudio@cinti.net
http://www.wavelengthaudio.com
ph.fx. 513-271-4186 USA
=========================================================================
From: William Eckle <wmeckle@uswest.net>
Subject: Bach's speakers ?
Date: Thu, 29 Oct 1998 11:10:41 -0700
Source: Sound Digest Archive v01.n473
At 08:09 PM 10/28/98 GMT, David Barnett wrote:
>
>>What kind of monitors do you think Bach had in his own studio?
>
>I think she used Altecs. Oh, wait, that's Wendy Carlos, nee
>Walter....
Little known sidebar:
Bach used to spend most all his time composing in his second story
room. His wife
repeatedly called him downstairs for his meals. He ignored her calls and
continued composing.
His wife, worried about his health, because of his missing so many
meals, fixed a hot
meal and took it up to his composing room.
This practice has survived to this day, only we call it:
|
|
|
Hot Bach's lunch !
=========================================================================
From: Eric Weitzman <eweitzman@acm.org>
Subject: RE: Bach's speakers ?
Date: Thu, 29 Oct 1998 12:32:11 -0800
Source: Sound Digest Archive v01.n473
This may not be true, but someone once told me that the
first Brandenburg Concerto was written with bach-loaded
horns in mind.
- - Eric
=========================================================================
From: "David B. Klein" <dklein@microtec.net>
Subject: Re: Bach's speakers ?
Date: Fri, 30 Oct 1998 02:37:45 -0800
Source: Sound Digest Archive v01.n473
Eric Weitzman wrote:
> This may not be true, but someone once told me that the
> first Brandenburg Concerto was written with bach-loaded
> horns in mind.
>
> - Eric
That would be the Second Brandenburg Concerto, but very funny none the
less!
dbk
=========================================================================
From: Joe Pledger <doodle@navicom.com>
Subject: Back!
Date: Mon, 10 Nov 1997 21:42:01 -0800
Source: Sound Digest Archive v01.n104
Hi Gang,
Just couldn't stand it! Waved my towel in the air, and flagged a passing
Vorlon Cruiser. Really missed being on the list!
Joe pledger
=========================================================================
From: davidbarnett@aristotle.net (David N. Barnett)
Subject: Re: Back!
Date: Tue, 11 Nov 1997 07:37:33 GMT
Source: Sound Digest Archive v01.n104
On Mon, 10 Nov 1997 21:42:01 -0800, Joe Pledger <doodle@navicom.com>
wrote:
>Just couldn't stand it! Waved my towel in the air, and flagged a passing
>Vorlon Cruiser. Really missed being on the list!
Don't you mean "Vogon?" If so, I hope you weren't subjected to any of
their poetry.
- --dnb
=========================================================================
From: STEVE CORNETT <SCORNETT@usagroup.com>
Subject: Re: Back!
Date: Tue, 11 Nov 1997 08:16:27 -0600
Source: Sound Digest Archive v01.n105
Joe Pledger wrote:
"Just couldn't stand it! Waved my towel in the air, and flagged a passing
Vorlon Cruiser. Really missed being on the list!"
To which dnb replied:
"Don't you mean "Vogon?" If so, I hope you weren't subjected to any of
their poetry."
Yes, I'm afraid Joe mixed his (Sci-Fi) metaphors. The Vorlons are part of
the Babylon 5 Universe.
Steve (Deep Thought) C.
=========================================================================
From: Grover Gardner <groverg@bellatlantic.net>
Subject: Re: Back!
Date: Tue, 11 Nov 1997 08:33:30 -0600
Source: Sound Digest Archive v01.n105
At 9:42 PM -0800 11/10/97, Joe Pledger wrote:
>Hi Gang,
>
>Just couldn't stand it! Waved my towel in the air, and flagged a passing
>Vorlon Cruiser. Really missed being on the list!
>
>Joe pledger
Yeah!
Grover Gardner
groverg@bellatlantic.net
=========================================================================
From: Marc Elmlund <marc@wineasy.se>
Subject: Re: Back!
Date: Tue, 11 Nov 1997 09:58:46 +0100
Source: Sound Digest Archive v01.n105
At 21.42 -0800 97-11-10, Joe Pledger wrote:
>Hi Gang,
>
>Just couldn't stand it! Waved my towel in the air, and flagged a passing
>Vorlon Cruiser. Really missed being on the list!
WB. I hope they didn't make you listen to any poetry.
Regards
Marc Elmlund
Stockholm, Sweden
aka marc@wineasy.se
=========================================================================
From: "Le Cleac'h J.-M." <lecleach@cgi.ensmp.fr>
Subject: Re: Back!
Date: Wed, 12 Nov 1997 10:16:52 +0100 (MET)
Source: Sound Digest Archive v01.n106
At 21:42 10/11/1997 -0800, Joe pledger wrote:
>Just couldn't stand it! Waved my towel in the air, and flagged a passing
>Vorlon Cruiser. Really missed being on the list!
That's a good thing!
Going out of the list you nearly made the mean age of the list members
became less than 40!
Best regards,
Jean-Michel Le Cleac'h
=========================================================================
From: Johari Yip <hfyip@pacific.net.sg>
Subject: Re: Back!
Date: Thu, 13 Nov 1997 07:12:52 +0800
Source: Sound Digest Archive v01.n106
Le Cleac'h J.-M. wrote:
>
> At 21:42 10/11/1997 -0800, Joe pledger wrote:
>
> >Just couldn't stand it! Waved my towel in the air, and flagged a passing
> >Vorlon Cruiser. Really missed being on the list!
>
> That's a good thing!
>
> Going out of the list you nearly made the mean age of the list members
> became less than 40!
>
> Best regards,
>
> Jean-Michel Le Cleac'h
Hi everyone,
Due to my overseas attachment, I'll have to unsubscribe from the joelist
for the moment. Can someone show me what I should do?
Thanks in advance and see you soon!
Regards,
Johari
=========================================================================
From: pitaro@ozemail.com.au
Subject: Re: Back!
Date: Thu, 13 Nov 1997 15:02:30 EST
Source: Sound Digest Archive v01.n107
** Reply to note from davidbarnett@aristotle.net (David N. Barnett) Tue, 11 Nov 1997 07:37:33 GMT
>
> On Mon, 10 Nov 1997 21:42:01 -0800, Joe Pledger <doodle@navicom.com>
> wrote:
>
> >Just couldn't stand it! Waved my towel in the air, and flagged a passing
> >Vorlon Cruiser. Really missed being on the list!
>
> Don't you mean "Vogon?" If so, I hope you weren't subjected to any of
> their poetry.
>
I don't know what all the fuss is about.
Vogon poetry is quite pleasing! :)
Regards,
Harry Pitaro
+-----------------------+---------------------------------------------+
| Melbourne, Australia | A good discussion is like a miniskirt; |
| | Short enough to retain interest |
| pitaro@ozemail.com.au | and long enough to cover the subject. |
+-----------------------+---------------------------------------------+
=========================================================================
From: "Lohse, Guenther VIM37" <Lohse.Guenther@dornier.dasa.de>
Subject: back horn chamber
Date: Thu, 18 Sep 97 08:29:00 PDT
Source: Sound Digest Archive v01.n029
hey all,
hey bert, robert, dave
there are some discussions on back chambers of backloaded horns I've heard
(between above list members). Because I am recently offline I could not
follow the discussion. Please can anyone mail me the discussion details.
g}nther
lohse.guenther@dornier.dasa.de
=========================================================================
From: Edgar Faulkner <efaulkne@wsunix.wsu.edu>
Subject: back horns
Date: Wed, 17 Sep 1997 15:05:25 -0700 (PDT)
Source: Sound Digest Archive v01.n028
All the interest in this type of enclosure has me wanting to start
another project, just for fun.
I have two pair of Audax HM130ZO drivers and would be interested in trying
them in this type of enclosure. How do I determin the parameters of such a
box? These drivers are not currently in use and I am willing to try almost
anything to get some 2way system they might work in.
Any refrences for additional information will be appreciated. Even if the
idea doesn't hold water please explain why.
______________________________
Ed Faulkner \ through a child's eyes
Instructional Support Services \ sky is blue
Washington State University \ grass is green
Pullman, WA 99164 \ I want to see again
(509) 335-7566 \
efaulkne@wsu.edu. \_________________________________
=========================================================================
From: tubesguy@execpc.com (Patrick Currie)
Subject: Back horns - New Lowther prices
Date: Wed, 17 Sep 1997 20:19:15 -0500
Source: Sound Digest Archive v01.n028
Please pardon the blatantly commercial content, but there is new Lowther
Club pricing intended to encourage folks to deal with the Club rather than
anyone in, say, Missouri. The new prices are:
PM6C - $420/pr (all prices are per pair, not including shipping)
7C - 490
2C - 640
PM6A - 649
7A - 1090
2A - 1150
5A - 1500
4A - 1800
DX2 - 650
3 - 725
The Lowther Club of America is also apparently going to some type of
internet/web site/some guy in northern California/based sales system, so if
you or anyone else is interested in Lowthers, please contact Tom Ronan or
me while we're still involved, which I suspect will not be long. You may
be able to save a buck, or even a couple. - Pat
Pat Currie, Lowther Club of America Upper Midwest Representative
(608)233-8956, 266-9290 (Madison, WI)
=========================================================================
From: darmah@goodnet.com
Subject: Re: backhorns PAUL AND GORDON ARE RIGHT!!!
Date: Sat, 28 Mar 1998 09:47:50 +0000
Source: Sound Digest Archive v01.n234
Hi Paul and Gordon:
Congrats on the following conclusion. I've been preaching what you
said below for a long time with regards to horn design.
> What I mean is that so many of these designs are full of $%#@. The
> longer the better, yea right then you have this midbass drop out.
I agree 100% with you. That's why I always call the Mau horn the
"Mau-PIPE" myself. And I don't mean this as a crtisism.
> Anyhow, I conclude that back-loading can be made to work well if you
> know what you are doing. I don't think that I do;
WRONG!!!!!!!!!!!!! If you've realized this then you're much closer to
knowing what you're doing than most others. You will have also have
realized (I think) that small horns are a lot more like pipes than is
generally excepted.
< I did some simulations of the Acousta a while back that suggested
<it should have good strong bass, louder than the mids, down to 40Hz
<or so - but that sure ain't what I hear!
And it isn't what most other people hear either.
I'm seriously thinking of getting myself into big trouble by adding a
"mini horn primer" to my web page.
But then I'll probably have to got into hiding.
Best Redards
Marc S. Wauters
darmah@goodnet.com
Internet Paging: "http://wwp.mirabilis.com/544722"
My Home Page: "http://www.goodnet.com/~darmah/"
=========================================================================
From: Yip Hin Fai Johari <hfyip@pacific.net.sg>
Subject: Re: backhorns PAUL AND GORDON ARE RIGHT!!!
Date: Sun, 29 Mar 1998 11:28:29 +0800
Source: Sound Digest Archive v01.n235
>< I did some simulations of the Acousta a while back that suggested
><it should have good strong bass, louder than the mids, down to 40Hz
><or so - but that sure ain't what I hear!
>
>And it isn't what most other people hear either.
I agree that the Acousta, to certain extent, outperforms the Mauhorn in the
Mid
but you can't deny the fact that it(Acousta) doesn't go down low enough to
really give you satisfying sound. So naturally, going for a longer horn to
go down lower
in the frequencies is the best way but it brings along with it a new sets
of problem.
Johari
=========================================================================
From: "J. Gordon Rankin" <waudio@cinti.net>
Subject: Re: backhorns PAUL AND GORDON ARE RIGHT!!!
Date: Mon, 30 Mar 98 11:08:47 -0500
Source: Sound Digest Archive v01.n237
Johari
As far as I know the Acousta was not really a design of Lowther and that
it has serious problems in itself.
My point is that not enough thought is going into these designs except
for the though of ultimate bass output. Instead someone should realize
that the throat has much to do with the amout of output needed and at
what freq you need it at.
Gordon
=======> Wavelength Audio <=======
mailto:waudio@cinti.net
http://www.wavelengthaudio.com
ph.fx. 513-271-4186 USA
=========================================================================
From: "P.A. & M. Almeflo" <sd@ljusdal.se>
Subject: backhorns (was: Why we use permaalloy)
Date: Thu, 26 Mar 1998 22:28:30 +0100
Source: Sound Digest Archive v01.n231
Gordon wrote:
> I would say that I think those that are designing the backhorns need to
> go back to school. Robert Lamarre is on the right track.
What track is that, is he leaving back loaded horns?
Best regards,
Per Arne Almeflo
=========================================================================
From: Paul Joppa <pdj@ISDNseattle.net>
Subject: Re: backhorns (was: Why we use permaalloy)
Date: Fri, 27 Mar 1998 16:52:56 -0800
Source: Sound Digest Archive v01.n233
J. Gordon Rankin wrote:
>
> >What track is that, is he leaving back loaded horns?
>
> What I mean is that so many of these designs are full of $%#@. The longer
> the better, yea right then you have this midbass drop out.
Probably should have chimed in here earlier. I had the chance last
year to visit Kevin Scott of Living Voice in Nottingham (UK). He makes
the Air Partner and Air Scout speakers (was recommended to me by Simon
Shilton by email). I heard the Air Scout (his 16 cubic foot
minimonitor!) and it was a mind-blowing experience, easily the best
I'd heard. He uses a back-horn on a 12" driver, but the horn is fairly
short and does not try to go lower than 60Hz or so. Acoustic crossover
to direct radiation must have been around 200 Hz or so; the midrange
kicks in at 500 - so very narrow bandwidths in the bass. (There was a
dual-12 front-horn-loaded subwoofer also in the system).
Anyhow, I conclude that back-loading can be made to work well if you
know what you are doing. I don't think that I do; I did some
simulations of the Acousta a while back that suggested it should have
good strong bass, louder than the mids, down to 40Hz or so - but that
sure ain't what I hear!
- -Paul Joppa
=========================================================================
From: "J. Gordon Rankin" <waudio@cinti.net>
Subject: Re: backhorns (was: Why we use permaalloy)
Date: Fri, 27 Mar 98 16:56:47 -0500
Source: Sound Digest Archive v01.n233
>What track is that, is he leaving back loaded horns?
What I mean is that so many of these designs are full of $%#@. The longer
the better, yea right then you have this midbass drop out.
I have a customer who built the BelCante Lowther design, from plans
supplied by Lowther with a PM5A. First thing I asked if he noticed the
drop out (See this is a 3M horn). The same is true with the Mauhorn.
Listen here is some simple info for back horn loading:
1) Determine the -3dB point of the driver in free space or better yet
loaded in a enclosure with a throat close to what you need.
2) Design a horn that the top freq is -3dB at the same point as 1
3) Live with the lowend not going down as far as you would like.
What has happened is that these so called designers are trying to reach
20Hz with a Lowther, well good luck! Reps yea maybe, Lowther no way. So
live with a 50Hz system and forget going any lower.
FYI, the customer above bought a pair of Reps1 put them in his BelCante
and well, WOW came to mind.
Gordon
=======> Wavelength Audio <=======
mailto:waudio@cinti.net
http://www.wavelengthaudio.com
ph.fx. 513-271-4186 USA
=========================================================================
From: "P.A. & M. Almeflo" <sd@ljusdal.se>
Subject: RE: backhorns (was: Why we use permaalloy)
Date: Sun, 29 Mar 1998 19:23:04 +0200
Source: Sound Digest Archive v01.n235
J. Gordon Rankin wrote:
> 1) Determine the -3dB point of the driver in free space or better yet
> loaded in a enclosure with a throat close to what you need.
>2) Design a horn that the top freq is -3dB at the same point as 1
What is top freq? Do you mean lowpass cutoff or highpass cutoff?
>Lowther no way. So live with a 50Hz system and forget going
>any lower.
Do you say that a Lowther has its -3dB point at 50Hz in free space?
Best regards,
Per Arne Almeflo
=========================================================================
From: "P.A. & M. Almeflo" <sd@ljusdal.se>
Subject: RE: backhorns (was: Why we use permaalloy)
Date: Sun, 29 Mar 1998 19:23:04 +0200
Source: Sound Digest Archive v01.n238
J. Gordon Rankin wrote:
> 1) Determine the -3dB point of the driver in free space or better yet
> loaded in a enclosure with a throat close to what you need.
>2) Design a horn that the top freq is -3dB at the same point as 1
What is top freq? Do you mean lowpass cutoff or highpass cutoff?
>Lowther no way. So live with a 50Hz system and forget going
>any lower.
Do you say that a Lowther has its -3dB point at 50Hz in free space?
Best regards,
Per Arne Almeflo
=========================================================================
From: Thomas Eberhard <Thomas.Eberhard@labmed.ki.se>
Subject: Re: backhorns (was: Why we use permaalloy)
Date: Tue, 31 Mar 1998 06:53:51 +0100
Source: Sound Digest Archive v01.n238
>Anyhow, I conclude that back-loading can be made to work well if you
>know what you are doing. I don't think that I do; I did some
>simulations of the Acousta a while back that suggested it should have
>good strong bass, louder than the mids, down to 40Hz or so - but that
>sure ain't what I hear!
>
>-Paul Joppa
sure ain't what I measure either.
Measured in center of horn opening using a Philips 9710 as a driver.
Hz dB (rellative at 200 Hz)
400 -18
315 -6
250 0
200 0
160 +2
125 0
100 -2
80 -10
63 -16
50 -18
Thomas H Eberhard
Clinical Microbiology VOX 08-5177 49 72
Karolinska Institute FAX 08-5177 58 50
S 171 76 Stockholm E-M Thomas.Eberhard@labmed.ki.se
"The higher we soar the smaller we appear to
those who cannot fly." Friedrich Wilhelm Nietzsche
=========================================================================
From: "P.A. & M. Almeflo" <sd@ljusdal.se>
Subject: RE: backhorns (was: Why we use permaalloy)
Date: Tue, 31 Mar 1998 19:13:25 +0200
Source: Sound Digest Archive v01.n239
J. Gordon Rankin wrote:
> FYI my Spike Fostex 168 Sigma horn info in response relative to 90Hz,
> Tractix 40Hz
>
> Freq Horn Combined
> 200 -8db 0
> 150 -6db 0
> 100 -3dB 2
> 90 0 1
> 80 1dB -1
> 70 2dB -2
> 50 6dB 0
> 40 9dB -2
> 30 2dB -5
> 20 -7dB -12
That looks really great; +/-2dB combined from 40-200Hz.
How did you measure the combined SPL?
Is the horn designed for 1/1, 1/2, 1/4 or 1/8 space?
What is the size of the horn mouth?
Do you feel you would gain from a subwoofer?
Are you satisfied with this driver and horn design?
With kindest regards,
Per Arne Almeflo
=========================================================================
From: "J. Gordon Rankin" <waudio@cinti.net>
Subject: RE: backhorns (was: Why we use permaalloy)
Date: Tue, 31 Mar 98 10:32:06 -0500
Source: Sound Digest Archive v01.n239
Per Arne Almeflo,
>What is top freq? Do you mean lowpass cutoff or highpass cutoff?
Sorry for the use of non technical terms, the top frequency or highpass
cutoff. But even more than that anyone who has made a Backhorn realizes
that they will keep going because information into the horn such as
higher bidbass and even midrange info is passed.
>>Lowther no way. So live with a 50Hz system and forget going
>>any lower.
>
>Do you say that a Lowther has its -3dB point at 50Hz in free space?
No that 50Hz is about the best you are going to do from the back horn.
FYI my Spike Fostex 168 Sigma horn info in response relative to 90Hz,
Tractix 40Hz
Freq Horn Combined
200 -8db 0
150 -6db 0
100 -3dB 2
90 0 1
80 1dB -1
70 2dB -2
50 6dB 0
40 9dB -2
30 2dB -5
20 -7dB -12
This only took about 2 solid months to get it that good, the second one
took 3 days.
Gordon
=======> Wavelength Audio <=======
mailto:waudio@cinti.net
http://www.wavelengthaudio.com
ph.fx. 513-271-4186 USA
=========================================================================
From: Thomas Eberhard <Thomas.Eberhard@labmed.ki.se>
Subject: Re: backhorns (was: Why we use permaalloy) part2
Date: Wed, 1 Apr 1998 07:09:46 +0100
Source: Sound Digest Archive v01.n240
>What did you use to measure with? I feel that I have good bass but now you
>got me wondering. But I have two Lowthers in one common backhorn and I would
>think that would make a big difference. Move your speakers side by side
>and put >them in the corner of your room you may like what you hear.If you
>toe them out >a little you will retain some if not most of your imaging.
I used a Technics Audio Frequency Analyser SH-8000. It is a sine wave
generator 20-20 000 Hz in 1/3 octave intervals with 8 Hz warble on top and
it have a microphone and a dB meter as well.
I later found out that the Philips was a bad choise of driver as it had a
Qt close to 1. I breifly tried a pair of Hokutone 8" drivers and they gave
better bass but I wanted to keep the fullrange concept. My conclusion is
that the Accousta size horn really is to small to work as a horn below 80
Hz and that the pipe like behaviour dominates below this frequency. An
option would be to have a big bass chamber giving a 12 dB cutof above 50 Hz
but then the advantage of high radiation resistance of a horn is lost. (If
we simplify the horn to a 12dB/ oct fall below 100 Hz and a 12dB/oct above
200 Hz the introduction of the bass chamber gives a system flat betwen
50-100 Hz with a 12 dB/oct fall below that and and a 12 db/oct above 100 hz
that increase to 24dB/oct above 200 Hz, this feature is present in some of
the Accousta variants).
Thomas
=========================================================================
From: "J. Gordon Rankin" <waudio@cinti.net>
Subject: Re: backhorns (was: Why we use permaalloy) part2
Date: Thu, 2 Apr 98 11:27:20 -0500
Source: Sound Digest Archive v01.n242
>I later found out that the Philips was a bad choise of driver as it had a
>Qt close to 1. I breifly tried a pair of Hokutone 8" drivers and they gave
>better bass but I wanted to keep the fullrange concept. My conclusion is
>that the Accousta size horn really is to small to work as a horn below 80
>Hz and that the pipe like behaviour dominates below this frequency. An
>option would be to have a big bass chamber giving a 12 dB cutof above 50 Hz
>but then the advantage of high radiation resistance of a horn is lost. (If
>we simplify the horn to a 12dB/ oct fall below 100 Hz and a 12dB/oct above
>200 Hz the introduction of the bass chamber gives a system flat betwen
>50-100 Hz with a 12 dB/oct fall below that and and a 12 db/oct above 100 hz
>that increase to 24dB/oct above 200 Hz, this feature is present in some of
>the Accousta variants).
Tom,
What is with the small mouth Lowther enclosures, are they just cutting
the horn off at say 30%? The mouth on my horn was 36" high...
I believe that more driver->horn reseach is needed in this area. You just
can't stick any old driver in a backhorn and expect it to work (unless
you are looking just to get sound out the other end). I believe that the
A and C drivers of Lowther fame should not be used in the same horns as
well as 6&7 should not be used in the same designs as 2&5's.
Gordon
=======> Wavelength Audio <=======
mailto:waudio@cinti.net
http://www.wavelengthaudio.com
ph.fx. 513-271-4186 USA
=========================================================================
From: Robert Peterson <rpeterso@arthur.avalon.net>
Subject: backhorn tips wanted
Date: Wed, 7 Oct 1998 20:16:03 -0500 (CDT)
Source: Sound Digest Archive v01.n445
I'm just finishing up my back loaded horns and thought I'd seek out some
tips on how to treat the back chamber. Mainly I'm concerned about mid
colorations from sound reflecting back into the driver. Some materials I
am considering are Deflex panels and modeling clay which seems like a very
dead and easy to use material. Any other notions... or should I leave it
clean?
Thanks,
Robert
=========================================================================
From: Robert Lamarre <rlamarre@rlacoustique.com>
Subject: Re: backhorn tips wanted
Date: Wed, 7 Oct 1998 23:25:25 -0400
Source: Sound Digest Archive v01.n445
At 08:16 PM 10/7/98 -0500, you wrote:
>I'm just finishing up my back loaded horns and thought I'd seek out some
>tips on how to treat the back chamber. Mainly I'm concerned about mid
>colorations from sound reflecting back into the driver. Some materials I
>am considering are Deflex panels and modeling clay which seems like a very
>dead and easy to use material. Any other notions... or should I leave it
>clean?
>Thanks,
>Robert
>
>
Hi Robert,
I have tried many back chamber treatment materials.
In all fairness, it depends on so many variables that your best bet is to try
Deflex, wool, clay, etc.... and choose the method YOU prefer the most.
Cheers,
========== Robert Lamarre ===========
RL Acoustique, Creator of The Lamhorn
rlamarre@rlacoustique.com------------
www.rlacoustique.com-----------------
ph./fax: 450-653-3461 Canada---------
=========================================================================
From: Paul Joppa <pdj@ISDNseattle.net>
Subject: Re: backhorn tips wanted
Date: Thu, 08 Oct 1998 20:21:37 -0700
Source: Sound Digest Archive v01.n447
Robert Peterson wrote:
>
> I'm just finishing up my back loaded horns and thought I'd seek out some
> tips on how to treat the back chamber. Mainly I'm concerned about mid
> colorations from sound reflecting back into the driver. ...snip...
Check out Speaker Builder last month - there are some actual
measurements of sound-absorbent materials at close to normal
incidence. This assumes of course that you really want to reduce
reflections, and not to tune them to a pleasing characteristic
instead. Which is often done while pretending that it's eliminating
reflections.
To significantly reduce the reflection at the first front-back
resonance frequency needs a near-optimum material whose thickness is
1/2 the cavity depth. Sonex foam for example (with the wedge-shaped
surface like in anechoic chambers) exists in 2", 3", and 4" depths,
suitable for 4", 6", and 8" cavities. Be warned though - this is not
"politically-correct" material, it's only scientific. Many audiophiles
will likely tell you to use something else that is technically a worse
absorber. And I'm not being entirely cynical here - it has often
happened that a scientifically-correct approach is not the best
sounding one, and the pseudo-scientific explanation may be bogus but
the sound is not!
hth,
- -Paul Joppa
=========================================================================
From: "Ken Dangerfield" <bpyakd@mail.island.net>
Subject: Backloaded horns
Date: Fri, 26 Sep 1997 15:11:58 -0800
Source: Sound Digest Archive v01.n045
For front loaded horns, one of the important factors in determining
low end cut off is the area of the mouth.
However, in many of the currently popular back loaded horns (e.g.
Medallion and the Lowther bicors) the mouth only flares vertically in
the last leg, whereas the horizontal dimension is maintained at the
same (relatively narrow) width for the full height of the enclosure.
If the last leg of the horn, starting from the last bend and
continuing to the mouth, employed the tractrix expansion in both the
horizontal and vertical planes (without increasing the height of the
mouth), one could increase the area of the mouth substantially,
thereby potentially improving the low end cut off, while at the same
time preserving the narrow baffle above the mouth to minimize
difraction of mids and highs.
I recognize that there are many other factors at work in determining
the overall performance of a back loaded horn. This just seems like
a relatively easy modification to an existing design which wouldn't
interfere with any of the other dimensions or parameters but might
aid the low end.
If someone has experimented with this or can point out the fallacy of
my question, I would be most interested in your comments. TIA
Regards,
Ken Dangerfield
=========================================================================
From: Thomas.Eberhard@labmed.ki.se (Thomas Eberhard)
Subject: RE:Backloaded horns
Date: Mon, 29 Sep 1997 19:44:37 +0200
Source: Sound Digest Archive v01.n048
>For front loaded horns, one of the important factors in determining
>low end cut off is the area of the mouth.
snip
>If the last leg of the horn, starting from the last bend and
>continuing to the mouth, employed the tractrix expansion in both the
>horizontal and vertical planes (without increasing the height of the
>mouth), one could increase the area of the mouth substantially,
>thereby potentially improving the low end cut off, while at the same
>time preserving the narrow baffle above the mouth to minimize
>difraction of mids and highs.
snip
>Regards,
>Ken Dangerfield
In the German journal Klang & Ton 5/96 they have the construction "Cheap
Trick 164" were they have a backloadad horn for the Fostex FE 103 Sigma.
They have a very narrow front, 15 cm but the horn opening flares to twise
that with.
They get a good response, measured in the horn mouth, down to 65-70 Hz.
With the back chamber undamped they got a uneven peaky response from the
horn and the waterfall plot showed some nasty ridges in the 1-8 kHz range.
Filling the chamber with cotton eliminated the peaks and ridges but also
attenuated the bass horn by 5 dB. Covering the walls with BoFoam eliminated
the ridges in the waterfall diagrams and reduced the peakyness with minimal
attenuation of the bass horn. They used a foldning with the horn moth
backwards so by having the opening close to the backwall it can be further
extended.
Thomas H Eberhard
Klinisk Mikrobiologi VOX 08-5177 49 72
Karolinska Sjukhuset FAX 08-5177 58 50
S 171 76 Stockholm E-M thomas@labmed.ki.se
The great tragedy of Science - the slaying of a beautiful hypothesis
by an ugly fact. - Thomas Henry Huxley
=========================================================================
From: Bastien Bouchard <bastien.bouchard@sympatico.ca>
Subject: Re: Backloaded horns
Date: Tue, 30 Sep 1997 09:56:26 -0400
Source: Sound Digest Archive v01.n049
Thomas Eberhard wrote:
Covering the walls with BoFoam eliminated
> the ridges in the waterfall diagrams and reduced the peakyness with minimal
> attenuation of the bass horn.
Thomas,
What is Bofoam? I can't figure exactly.
Bastien
=========================================================================
From: "Mark Donen" <soledadd@worldnet.att.net>
Subject: Back loaded horns
Date: Wed, 7 Jan 1998 12:12:30 -0500
Source: Sound Digest Archive v01.n155
Anyone have plans for backloaded horns. I have seen photos of two JBL cabs
that look good. C55 & C43. They are for double and single 15" respectively.
Does anyone know em?
TIA
Mark
=========================================================================
From: "Ken Dangerfield" <bpyakd@mail.island.net>
Subject: Backloaded horns and Reactance Annulling
Date: Tue, 30 Sep 1997 11:42:06 -0800
Source: Sound Digest Archive v01.n049
In his "Showhorn" article in Speaker Builder 2/90, Dr. Edgar observes
that throat reactance (which rises as the flare frequency is
approached) will choke off the low end response of a horn before the
flare frequency is reached. However, this throat reactance can be
"annulled" by use of a sealed back chamber of appropriate volume. He
then presents formulae for calculating the theoretical optimum throat
size and back chamber volume for a given driver/horn combination.
In a typical backloaded horn, what is considered to be the throat?
Also, the back chamber (if there is one at all) is not sealed and is
simply a direct extension of the horn itself. In some designs (some
Lowthers for example) the driver fires back directly into the
uppermost part of the horn and there is no additional volume behind
the driver which could be regarded as a "back chamber".
So with this in mind:
1. By what means is reactance annulling accomplished in a
backloaded horn ?
2. Are there formulae adapted to calculating for backloaded horns
the values which are analagous to throat size and back chamber volume
in a frontloaded horn so that the appropriate amount of "annulling"
can be accomplished? If so, where can I find them?
TIA
Regards,
Ken Dangerfield
=========================================================================
From: Michel Paquette <paqm01@GEL.USherb.CA>
Subject: Re: Backloaded horns and Reactance Annulling
Date: Tue, 30 Sep 1997 18:29:20 -0400
Source: Sound Digest Archive v01.n050
Hello Ken,
I can look in Beranek's book on Acoustics here at the library. I doubt
that you would be able to do some reactance annulling with a horn on both
sides of the driver. In fact, I wonder if the having two horns worsens
the problem by have the same reactance problem on both sides of the driver
(supposing similart types of horns on the front and the rear). OTOH, it
could be that since that the horns are driven out of phase it does act like
reactance annulling but I doubt that also. You can always phone Dr Edgar.
I did once and he was very nice person to talk to.
best regards,
Michel
>In his "Showhorn" article in Speaker Builder 2/90, Dr. Edgar observes
>that throat reactance (which rises as the flare frequency is
>approached) will choke off the low end response of a horn before the
>flare frequency is reached. However, this throat reactance can be
>"annulled" by use of a sealed back chamber of appropriate volume. He
>then presents formulae for calculating the theoretical optimum throat
>size and back chamber volume for a given driver/horn combination.
>
>In a typical backloaded horn, what is considered to be the throat?
>Also, the back chamber (if there is one at all) is not sealed and is
>simply a direct extension of the horn itself. In some designs (some
>Lowthers for example) the driver fires back directly into the
>uppermost part of the horn and there is no additional volume behind
>the driver which could be regarded as a "back chamber".
>
>So with this in mind:
>
>1. By what means is reactance annulling accomplished in a
>backloaded horn ?
>
>2. Are there formulae adapted to calculating for backloaded horns
>the values which are analagous to throat size and back chamber volume
>in a frontloaded horn so that the appropriate amount of "annulling"
>can be accomplished? If so, where can I find them?
>
>TIA
>Regards,
>Ken Dangerfield
=========================================================================
From: cjg2@concentric.net
Subject: Backloaded horns, full-range driver ???s
Date: Tue, 27 Oct 1998 22:37:40 -0500
Source: Sound Digest Archive v01.n471
Could anyone point me to some references on design+construction of rear
loaded horns? I have read several SP and 'net articles on enclosures
designed specifically for Lowthers, but I'd like to build something a la
Diatones and some other fullranges I've got around (Altec 755Es and Stephens
FR80s). I assume the horn calculations are the same for backloaded as for
frontloaded, but am guessing there are some special design considerations
(like the recently mentioned compression chamber size, etc.) Anything from
Speaker Builder, AES journals, or other?
The practicality (read--simplicity in design and sound!) of fullrangers is
just what the doctor ordered for me...limited space and finances.
Admittedly, I'd love to have horns from 20hz on up, but that will have to
wait. In the meantime, midrange magic, absence of HF nastiness, and
reasonable LF to 50hz is just fine.
BTW, anybody know anything about 755Es, like what makes them different from
Cs (the magnet is definitely not alnico)? I haven't had them in cabinets
yet, but they make nice sound from about 45hz to 17kHz (amazed I can hear
that high) on the oscillator.
Best wishes--Chris
=========================================================================
From: Martin Needleman <mrndlmn@bayserve.net>
Subject: Re: Backloaded horns, full-range driver ???s
Date: Tue, 27 Oct 1998 23:04:15 -0500 (EST)
Source: Sound Digest Archive v01.n471
Hey Chris,
Your 80FRs and 755s will drop into an unaltered Lowther backhorn cabinet
without a fuss. Try it and be prepared for magic.
Say Goodnight Gracie.
mrn
On Tue, 27 Oct 1998 cjg2@concentric.net wrote:
> Could anyone point me to some references on design+construction of rear
> loaded horns? I have read several SP and 'net articles on enclosures
> designed specifically for Lowthers, but I'd like to build something a la
> Diatones and some other fullranges I've got around (Altec 755Es and Stephens
> FR80s). I assume the horn calculations are the same for backloaded as for
> frontloaded, but am guessing there are some special design considerations
> (like the recently mentioned compression chamber size, etc.) Anything from
> Speaker Builder, AES journals, or other?
>
> The practicality (read--simplicity in design and sound!) of fullrangers is
> just what the doctor ordered for me...limited space and finances.
> Admittedly, I'd love to have horns from 20hz on up, but that will have to
> wait. In the meantime, midrange magic, absence of HF nastiness, and
> reasonable LF to 50hz is just fine.
>
> BTW, anybody know anything about 755Es, like what makes them different from
> Cs (the magnet is definitely not alnico)? I haven't had them in cabinets
> yet, but they make nice sound from about 45hz to 17kHz (amazed I can hear
> that high) on the oscillator.
>
> Best wishes--Chris
>
=========================================================================
From: Martin Needleman <mrndlmn@bayserve.net>
Subject: Re: Backloaded horns, full-range driver ???s
Date: Wed, 28 Oct 1998 18:47:38 -0500 (EST)
Source: Sound Digest Archive v01.n472
Hey Gordon,
Speaking from current experience, dropping the 755A into a backhorn is
anything but a waste of time. Fitting them into a Lowther Acousta 115
cabinet absolutely transformed my 1957 Altec 755A's (thanks Robert
Root!). I hated these things in the recommended 2 cubic foot box. Liked
them much better in a largish open baffle but the backhorn finally allows
me to understand that the reputation of these silly little puppies is
justified - glorious quick mids and a lower register that drops to 70Hz
tunefully with impact and authority. Voices so real that, at times,
guests have looked around trying to find the speaker/singer. Treble is
more than adequate for my faltering 65 year old ears.
We're not talking theory here. We're not talking T/S parameters. We're
talking music. We're talking cleaning the wax out of our ears and
listening.
On Wed, 28 Oct 1998, J. Gordon Rankin wrote:
> Chris,
>
> Pick your drivers well, both the 755 and Diatone are not good picks for
> backhorns. The 755 was made for sealed and the P610MB for ported. Using
> them in a backhorn would be a waste of time.
<================ snip =====================>
>
> Have fun, hope you have a lot of patients.
>
> Gordon
Golly, gosh Mr. Peabody. I didn't know Chris was a doctor.
mrn
=========================================================================
From: Paul Joppa <pdj@ISDNseattle.net>
Subject: Re: Backloaded horns, full-range driver ???s
Date: Wed, 28 Oct 1998 21:51:42 -0800
Source: Sound Digest Archive v01.n472
J. Gordon Rankin wrote:
> ...snip...
> As far as info use the expansion type that you are interested in
> (Tractix, Expontial). Treat the horn as though you were designing a
> straight horn, do not consider this a bass horn with a sealed back area.
> Determine the lowend cutoff and throat size and length. Most people agree
> the length should be more than 50% of the needed length. Also horns with
> very long lengths (over 2M) tend to be very poor preformers. Also
> cornering at less than 120 degrees is a must, stay away from the horns
> that have 180 degree bends as the response is very irratic.
...snip...
Great post, Gordon - thanks!
One other point - backhorns usually have a small back chamber between
the driver and the horn proper. This volume acts as a lowpass filter
so the horn only operates at low frequencies, usually below 200 Hz or
less. Sort of an acoustic subwoofer crossover. All the usual articles
on horn design mention this (as a front chamber of course!). With
low-mass cones, the acoustic resonances of this small box are audible
through the cone, so it is somewhat important at higher frequencies
also.
- -Paul Joppa
=========================================================================
From: "J. Gordon Rankin" <waudio@cinti.net>
Subject: Re: Backloaded horns, full-range driver ???s
Date: Wed, 28 Oct 98 11:10:54 -0500
Source: Sound Digest Archive v01.n472
>Could anyone point me to some references on design+construction of rear
>loaded horns? I have read several SP and 'net articles on enclosures
>designed specifically for Lowthers, but I'd like to build something a la
>Diatones and some other fullranges I've got around (Altec 755Es and Stephens
>FR80s). I assume the horn calculations are the same for backloaded as for
>frontloaded, but am guessing there are some special design considerations
>(like the recently mentioned compression chamber size, etc.) Anything from
>Speaker Builder, AES journals, or other?
Chris,
Pick your drivers well, both the 755 and Diatone are not good picks for
backhorns. The 755 was made for sealed and the P610MB for ported. Using
them in a backhorn would be a waste of time.
The drivers that work (or require) the back horn have low Qt and high Fs.
For these the only way to get bass is by backloading (amplifing) that
little bit available at lower frequencies. Fostex, Lowther, Reps etc...
~~~~~~~~~~
As far as info use the expansion type that you are interested in
(Tractix, Expontial). Treat the horn as though you were designing a
straight horn, do not consider this a bass horn with a sealed back area.
Determine the lowend cutoff and throat size and length. Most people agree
the length should be more than 50% of the needed length. Also horns with
very long lengths (over 2M) tend to be very poor preformers. Also
cornering at less than 120 degrees is a must, stay away from the horns
that have 180 degree bends as the response is very irratic.
Have fun, hope you have a lot of patients.
Gordon
=======> Wavelength Audio <=======
mailto:waudio@cinti.net
http://www.wavelengthaudio.com
ph.fx. 513-271-4186 USA
=========================================================================
From: "J. Gordon Rankin" <waudio@cinti.net>
Subject: Re: Backloaded horns, full-range driver ???s
Date: Thu, 29 Oct 98 11:26:05 -0500
Source: Sound Digest Archive v01.n473
Paul, Martin etc...
>One other point - backhorns usually have a small back chamber between
>the driver and the horn proper. This volume acts as a lowpass filter
>so the horn only operates at low frequencies, usually below 200 Hz or
>less. Sort of an acoustic subwoofer crossover. All the usual articles
>on horn design mention this (as a front chamber of course!). With
>low-mass cones, the acoustic resonances of this small box are audible
>through the cone, so it is somewhat important at higher frequencies
>also.
There is some calculations on this volume and the upper point in the
response of the horn, but I have found that even more monkeying around is
required to make sure the higher freq. do not come through the horn.
Martin, I was not claiming that 755's would not sound good in backhorns,
maybe not needed. You could get better response out of the 755's using a
1.5CU ported enclosure down -3dB at (if my memory is correct) like 35Hz.
This is of course much easier and much less expensive than a horn to
recreate bass to 35Hz. I think the driver should be taken into context
when designing any type of enclosre. Just shoehorning (SP????) a speaker
into a cabinet would be silly. Many drivers fit only into one or maybe
two types of enclosures for the best results.
Gordon
=======> Wavelength Audio <=======
mailto:waudio@cinti.net
http://www.wavelengthaudio.com
ph.fx. 513-271-4186 USA
=========================================================================
From: "Moore, Larry Dean" <l-moore@onu.edu>
Subject: Back on line!
Date: Tue, 25 Aug 1998 09:58:34 -0400
Source: Sound Digest Archive v01.n400
Well gang, I'm back on line. I have taken a leave of absences from Lucent
Technologies and am now attending law school at Ohio Northern University.
If anyone wishes to contact me my new e-mail is l-moore@onu.edu I doubt
that I will have as much time as I had in the past; but, I will make an
effort to contribute to the list as time allows.
Currently, I am tweeking the Montford amplifiers which I spoke about prior
to leaving. Last night I ran across some bogus 5687s and faught with them
for about 3 hours before I discovered that one was the major source of my
problems sonically. Now, I have some 7119 in place and I'll really
starting to like them. In fact, this pushed me back to messing with the
crossover for the petite onken altec 511B/802 combo which I am now using.
Take care,
L.D. Moore
=========================================================================
From: tubesguy@mail.execpc.com (Patrick Currie)
Subject: Back online, w/ a pentode query
Date: Sun, 15 Feb 1998 16:16:35 -0500
Source: Sound Digest Archive v01.n193
Whew! The recent fix to keep spammers out inadvertently, perhaps, had
prevented me from posting to the list until I un- and then re-subscribed.
Thanks to Tom Ronan for the advice. Imagine how frustrating it was to have
people asking about how humans can generate a vacuum and not being able to
suggest seeking advice from Monica Lewinsky.
But on to matters audio. I am doing an amp using the 6AC7 as a driver, and
I need a screen supply. I would like to use one OD3 for both channels. Good
idea, or should the supplies be kept separate?
If I use the OD3, even for both channels, I am at the absolute lower limit
for current draw, since each of the screens draws only 2.5ma. Can I just
hang a bleeder resistor on the output of the OD3 to draw a little more
current through it?
I want to power the screens from a B+ supply of about 400v. Any
suggestions for the limiting resistor R if I draw a total of 20ma from the
OD3?
Any other suggestions for screen strategies also appreciated. I asked a
few days ago about SS current-regulator diodes, but got no takers.
TIA - Pat
Pat Currie (tubesguy@execpc.com)
=========================================================================
From: Hugh Dean <aspen@alphalink.com.au>
Subject: Re: Back online, w/ a pentode query
Date: Mon, 16 Feb 1998 09:22:33 +1100
Source: Sound Digest Archive v01.n193
Hi Patrick, you wrote:
>
> Whew! The recent fix to keep spammers out inadvertently, perhaps, had
> prevented me from posting to the list until I un- and then re-subscribed.
> Thanks to Tom Ronan for the advice. Imagine how frustrating it was to have
> people asking about how humans can generate a vacuum and not being able to
> suggest seeking advice from Monica Lewinsky.
A wonderful joke. Reminds of the one about Titanic...
> But on to matters audio. I am doing an amp using the 6AC7 as a driver, and
> I need a screen supply. I would like to use one OD3 for both channels. Good
> idea, or should the supplies be kept separate?
NO, keep them separate because the B+, where you support the OD3, will
be slightly modulated by the audio signal and thus you will suffer
crosstalk.
> If I use the OD3, even for both channels, I am at the absolute lower limit
> for current draw, since each of the screens draws only 2.5ma. Can I just
> hang a bleeder resistor on the output of the OD3 to draw a little more
> current through it?
Bleeder resistors are fine. However, the screen current is the go, and
according to Jean-Michel, varies almost linearly with plate current;
the voltage is not so important. So you would need to ensure that the
screen current can vary readily with the plate current, albeit with 150V
or so between them at all times.
> I want to power the screens from a B+ supply of about 400v. Any
> suggestions for the limiting resistor R if I draw a total of 20ma from the
> OD3?
Is the OD3 about 150V? I believe so. 400 - 150 is 250V, which is
dropped across the limiting resistor to ground. This would give you
12K5, rated at 5W. So choose about a 12W resistor for reasonable safety
margin.
Cheers,
Hugh R. Dean
Melbourne, Australia
> Any other suggestions for screen strategies also appreciated. I asked a
> few days ago about SS current-regulator diodes, but got no takers.
>
> TIA - Pat
>
> Pat Currie (tubesguy@execpc.com)
=========================================================================
From: "Le Cleac'h J.-M." <lecleach@cgi.ensmp.fr>
Subject: Re: Back online, w/ a pentode query
Date: Mon, 16 Feb 1998 14:07:48 +0100 (MET)
Source: Sound Digest Archive v01.n197
At 09:22 16/02/1998 +1100, you wrote:
>Hi Patrick, you wrote:
>>
>> Whew! The recent fix to keep spammers out inadvertently, perhaps, had
>> prevented me from posting to the list until I un- and then re-subscribed.
>> Thanks to Tom Ronan for the advice. Imagine how frustrating it was to have
>> people asking about how humans can generate a vacuum and not being able to
>> suggest seeking advice from Monica Lewinsky.
>
>A wonderful joke. Reminds of the one about Titanic...
Let's come back to tube amp please! I give the example:
Let's take a classical single end plugged with buggle boys, let's call it Paula.
Then take a parallel feed working the tubes hot, call it Monica.
Then, let's take a powerfull push-pull, no Sovtek allowed there, but it
possess a weird kinked tube, call it William .
Which one is the most mellow sounding when playing?
(a really bad joke, I know...)
Best regards
Jean-Michel Le Cleac'h, Paris, France
=========================================================================
From: "Frank Deutschmann" <fdeutsch@blackrock.com>
Subject: Re: Back online, w/ a pentode query
Date: Fri, 20 Feb 1998 12:39:49 -0500
Source: Sound Digest Archive v01.n197
On Feb 20, 6:23pm, Le Cleac'h J.-M. wrote:
> Hey, here comes the lost message!
> 5 days between the moment I send it and the moment it appears on the list,
> not bad! (The speed of electrons or is it the speed of electromagnetic
waves
> slow down a lot those days...)
The JoeNet is, it would seem, a rather poor filter; so much noise and ripple
in the passband, in both amplitude and phase response. But we love it
anyway....
Hey, would a thread about skiing at the Olympics be on topic? They did,
after all, have a vacuum tube in the downhill! (Their tube had lots of
compression, though.)
- -frank
=========================================================================
From: "Frank Deutschmann" <fdeutsch@blackrock.com>
Subject: Re: Back online, w/ a pentode query
Date: Fri, 20 Feb 1998 15:38:21 -0500
Source: Sound Digest Archive v01.n197
On Feb 20, 7:09pm, Le Cleac'h J.-M. wrote:
> >Hey, would a thread about skiing at the Olympics be on topic? They did,
> >after all, have a vacuum tube in the downhill! (Their tube had lots of
> >compression, though.)
>
> Sorry, this one is too tough for me...
I suppose your sports coverage is a little different, and perhaps there is a
translation aspect too. Anyway, in the American (CBS) (really pretty crappy)
coverage of the Downhill, the anouncer kept saying, "and there he goes, into
the Vacuum Tube...." What they were talking about is a section of the course
where the course has a fairly tight, banked turn (compression turn) into a
narrow section named the "vacuum tube". Searching on the web, I finally came
up with this site: http://www.shinmai.co.jp/oly-eng/kaijo/happo.htm (for all
the hyped IBM coverage, the best IBM and CBS can do is some basic stats on
the course). So I guess it was a bit obscure -- but its pretty funny that
the Japanese named a section of the Olympic downhill a "vacuum tube"!
- -frank
=========================================================================
From: "Le Cleac'h J.-M." <lecleach@cgi.ensmp.fr>
Subject: Re: Back online, w/ a pentode query
Date: Fri, 20 Feb 1998 18:23:07 +0100 (MET)
Source: Sound Digest Archive v01.n197
At 14:07 16/02/1998 +0100, you wrote:
>Let's come back to tube amp please! I give the example:
<CUT>
Hey, here comes the lost message!
5 days between the moment I send it and the moment it appears on the list,
not bad! (The speed of electrons or is it the speed of electromagnetic waves
slow down a lot those days...)
Best regards,
Jean Michel Le Cleac'h
=========================================================================
From: davidbarnett@aristotle.net (David N. Barnett)
Subject: Re: Back online, w/ a pentode query
Date: Fri, 20 Feb 1998 18:49:19 GMT
Source: Sound Digest Archive v01.n197
On Mon, 16 Feb 1998 14:07:48 +0100 (MET), "Le Cleac'h J.-M."
<lecleach@cgi.ensmp.fr> wrote:
>Then take a parallel feed working the tubes hot, call it Monica.
I think this amp has a hum problem....
- --dnb
=========================================================================
From: "Le Cleac'h J.-M." <lecleach@cgi.ensmp.fr>
Subject: Re: Back online, w/ a pentode query
Date: Fri, 20 Feb 1998 19:09:25 +0100 (MET)
Source: Sound Digest Archive v01.n197
At 12:39 20/02/1998 -0500, you wrote:
>On Feb 20, 6:23pm, Le Cleac'h J.-M. wrote:
>> Hey, here comes the lost message!
>> 5 days between the moment I send it and the moment it appears on the list,
>> not bad! (The speed of electrons or is it the speed of electromagnetic
>waves
>> slow down a lot those days...)
>
>The JoeNet is, it would seem, a rather poor filter; so much noise and ripple
>in the passband, in both amplitude and phase response.
Nice joke too!
>Hey, would a thread about skiing at the Olympics be on topic? They did,
>after all, have a vacuum tube in the downhill! (Their tube had lots of
>compression, though.)
Sorry, this one is too tough for me...
Best regards,
Jean-Michel Le Cleac'h, Paris, France
=========================================================================
From: Stuart Williams <stuart@titus.u-strasbg.fr>
Subject: RE: Back online, w/ a pentode query
Date: Sat, 21 Feb 1998 09:38:03 +0100 (MET)
Source: Sound Digest Archive v01.n198
On Sat, 21 Feb 1998, Sellek, Grant (TSA) wrote:
> >From: Frank Deutschmann[SMTP:fdeutsch@blackrock.com]
> >a section of the course
> >where the course has a fairly tight, banked turn (compression turn) into a
> >narrow section named the "vacuum tube".... -- but its pretty funny that
> >the Japanese named a section of the Olympic downhill a "vacuum tube"!
>
> maybe they just got "venturi tube" wrong in naming it?
>
yeah, but if you hit a compression wrong in a tuck, you will find yourself
with a vacuum in your lungs.
Stuart
=========================================================================
From: "Sellek, Grant (TSA)" <Grant.Sellek@roads.sa.gov.au>
Subject: RE: Back online, w/ a pentode query
Date: Sat, 21 Feb 1998 14:53:57 +1030
Source: Sound Digest Archive v01.n198
>From: Frank Deutschmann[SMTP:fdeutsch@blackrock.com]
>a section of the course
>where the course has a fairly tight, banked turn (compression turn) into a
>narrow section named the "vacuum tube".... -- but its pretty funny that
>the Japanese named a section of the Olympic downhill a "vacuum tube"!
maybe they just got "venturi tube" wrong in naming it?
Grant Sellek
Adelaide, Australia
grant.sellek@roads.sa.gov.au
=========================================================================
From: "Le Cleac'h J.-M." <lecleach@cgi.ensmp.fr>
Subject: Re: Back online, w/ a pentode query
Date: Mon, 23 Feb 1998 09:10:21 +0100 (MET)
Source: Sound Digest Archive v01.n198
At 15:38 20/02/1998 -0500, Frank Deutschmann wrote:
>On Feb 20, 7:09pm, Le Cleac'h J.-M. wrote:
>> Sorry, this one is too tough for me...
>I suppose your sports coverage is a little different, and perhaps there is a
>translation aspect too. Anyway, in the American (CBS) (really pretty crappy)
>coverage of the Downhill, the anouncer kept saying, "and there he goes, into
>the Vacuum Tube...."
OK, I get it now! (I knew "the tube" in waves surfing not that one)
Thanks for my vocabulary enrichment.
Best regards,
Jean-Michel Le Cleac'h, Paris, France
=========================================================================
From: tubesguy@mail.chorus.net (Patrick Currie)
Subject: Back on the Joenet
Date: Tue, 3 Nov 1998 17:41:56 -0600
Source: Sound Digest Archive v01.n479
Phew, that was tough. A whole day off the list, due to a provider switch.
Did I miss anything?
My new email address should be in the header. If not, it is: tubesguy@chorus.net
- - Pat
=========================================================================
From: Joe Pledger <doodle@navicom.com>
Subject: Back & Thanks.
Date: Tue, 11 Nov 1997 08:53:23 -0800
Source: Sound Digest Archive v01.n105
Thanks Gang,
I stand corrected, must have been the Vogon...but without a fish in my
ear, I couldn't understand anything! ;-)
Good to be back!
Joe Pledger
=========================================================================
From: Jeremy Epstein <70664.154@compuserve.com>
Subject: Back To Mono!
Date: Tue, 21 Oct 1997 12:56:40 -0400
Source: Sound Digest Archive v01.n078
*NOTE : THIS POST HAS **NOTHING** TO DO WITH
NATURAL-SOUNDING RECORDINGS OF ACOUSTIC INSTRUMENTS*
I listen in mono all the time, much of my favorite music was recorded that way. I just flick the mon
o switch on my preamp, I have
a mono feed into a conventional stereo playback setup.
Last night I was enjoying my Japanese Chess Chuck Berry box set, "Very Good"
and I was fascinated by detail I heard in the mix - these records usually had a lead guitar and voca
l overdubbed on a backing track, and
some at-times-severe tape echo also mixed in. It was very easy to hear
which elements were on which generation, where the tape echo was
being manipulated (Oh Carol!) and what the drummer had for breakfast (Wheaties and bourbon.)
Apart from these records, there is a LOT of spatial info on mono discs -
and you don't have to be Phil or Brian to hear it!
Back to Mono!
- -j
=========================================================================
From: dball@esper.com (David Ball)
Subject: Re: Back To Mono!
Date: Tue, 21 Oct 1997 15:30:02 -0400
Source: Sound Digest Archive v01.n078
At 12:56 PM 10/21/97 -0400, Jeremy Epstein wrote:
>*NOTE : THIS POST HAS **NOTHING** TO DO WITH
>NATURAL-SOUNDING RECORDINGS OF ACOUSTIC INSTRUMENTS*
>
>I listen in mono all the time, much of my favorite music was recorded that
way. I just flick the mono switch on my preamp, I have
>a mono feed into a conventional stereo playback setup.
Darn near everything I listen to was originally recorded mono. I've got a
dedicated mono/78 rig in my upstairs where space is limited due to a large
number of 78s lining my walls--this is an old Fisher 500 mono receiver
playing through a Bozak kettle drum. Mono LPs and CDs play on my stereo rig
downstairs (mono switch flipped on the preamp) through the 2a3/Altec horn
rig. I like 'em both--they're just good for different things. The Fisher
is like a really really good radio with a turntable on it, and the 2A3/horn
setup has a more detailed and dynamic sound. But I have to admit that what
determines whether I listen in stereo or mono has a lot more to do with what
music I like than any internal philosophical struggle over "which is the
better way to listen."
Dave
=========================================================================
From: Dave Stagner <dstagner@icarus.net>
Subject: Bad 83?
Date: Mon, 23 Feb 1998 15:57:25 -0600 (CST)
Source: Sound Digest Archive v01.n199
How does one spot a bad 83 rectifier tube? I just got a tube tester that
uses one, and i think it's gone bad. When i turn it on, i can see the
purple glow through one of the test sockets, but it flickers irregularly,
and finally dies down to just a small spot of purple. I can't get good
test readings, either. When i put in a tube and press the test buttons, i
can see the rectifier flash, and sometimes go out completely. :(
I'm assuming i need a new tube here... does this sound right?
- -dave
Practice beautiful randomness and act kind of senseless.
<dstagner@icarus.net>
=========================================================================
From: Jeremy Epstein <jepstein@shwd.com>
Subject: Bad Playback
Date: Mon, 14 Dec 1998 10:01:20 -0500
Source: Sound Digest Archive v01.n537
I had the worst sound reproduction experience I can remember on Saturday
night. I went to a local production of Tchaikovsky's "Nutcracker Suite"
ballet, the dancers performed to a pre-recorded playback.
Ouch. First off, the level in the house was way beyond rock-concert,
totally overamped. Second, the playback system was not up to that level
of dynamics. Either something in the playback chain was overloaded,
playback was from a tape that had been made pinned into the red, or I
don't know what, anyway, every time there was a forte, didn't matter
which instrument, my ears bled. It could have been a harsh resonance in
the hall, too : the louder flute passages were particularly awful.
Such beautiful music, too, what a pity.
- -j
- --
=====================================
Jeremy Epstein .... jepstein@shwd.com
=====================================
=========================================================================
From: "Ken Dangerfield" <bpyakd@mail.island.net>
Subject: Re: Bad Playback
Date: Mon, 14 Dec 1998 13:23:14 -0800
Source: Sound Digest Archive v01.n538
On 14 Dec 98 Jeremy Epstein said:
> My five year old daughter was rapt (through the middle of the second
> act, when most grownups got fidgety too) so I consider it a
> successful evening. Decent punch, and very good cookies, at the
> reception.
Which is wonderful and makes the rest of it pale by comparison.
Regards,
Ken Dangerfield
=========================================================================
From: AnnaLogg@aol.com
Subject: Re: Bad Playback
Date: Mon, 14 Dec 1998 15:19:48 EST
Source: Sound Digest Archive v01.n538
In a message dated 98-12-14 10:24:31 EST, jepstein@shwd.com writes:
> I had the worst sound reproduction experience I can remember on Saturday
> night. I went to a local production of Tchaikovsky's "Nutcracker Suite"
> ballet, the dancers performed to a pre-recorded playback.
Actually, the *ballet* is called "The Nutcracker." The Nutcracker *Suite* is
just that -- a suite of excerpts from the complete ballet performed in concert
(actually, primarily on recordings) and just about every major orchestra has
at least 2 or 3 recordings of these excerpts (the "suite") to their credit.
But, on to the main topic:
>
> Ouch. First off, the level in the house was way beyond rock-concert,
> totally overamped. Second, the playback system was not up to that level
> of dynamics. Either something in the playback chain was overloaded,
> playback was from a tape that had been made pinned into the red, or I
> don't know what, anyway, every time there was a forte, didn't matter
> which instrument, my ears bled. It could have been a harsh resonance in
> the hall, too : the louder flute passages were particularly awful.
>
> Such beautiful music, too, what a pity.
>
Is this the first time you've heard it???? If so, may I suggest you continue
on down this road -- there are untold musical wonders awaiting you if you do.
But back to reality -- this is typical of the result we have come to in the
current cost of the arts. Most local ballet schools will mount a holiday
production of The Nutcracker because it is such popular fare at this time of
year, the kids love it, it gives the young dancers something to shine in and
it helps to promote their dance businesses. Yet unless possessing extensive
grant funding to foot the costs, few can afford a live orchestra. And, the
taped copies are usually an amateur effort administered by people who know
less than nothing about sound systems, much less about good sound. In other
words, they can't afford professional sound technicians either (even assuming
they could find one who wasn't stone deaf, anyway). I speak from personal
experience when I tell you that these productions are largely the work of
volunteers, and the artistic directors have to pretty much work with what they
have given to them.
So, Jeremy, since you undoubtedly found other pleasurable merit in the event,
why don't you volunteer to assist with next year's production and see to it
that the music reproduction is worthy of the effort? It might be fun, not to
mention very rewarding as well as enlightening!
Happy holidays,
Anna
=========================================================================
From: Jeremy Epstein <jepstein@shwd.com>
Subject: Re: Bad Playback
Date: Mon, 14 Dec 1998 15:43:41 -0500
Source: Sound Digest Archive v01.n538
AnnaLogg@aol.com wrote:
>
> In a message dated 98-12-14 10:24:31 EST, jepstein@shwd.com writes:
>
> > I had the worst sound reproduction experience I can remember on Saturday
> > night. I went to a local production of Tchaikovsky's "Nutcracker Suite"
> > ballet, the dancers performed to a pre-recorded playback.
>
> Actually, the *ballet* is called "The Nutcracker."
N.B.
> But, on to the main topic:
> > Such beautiful music, too, what a pity.
> >
> Is this the first time you've heard it???? If so, may I suggest you continue
> on down this road -- there are untold musical wonders awaiting you if you do.
Oh, no, one could hardly have missed the more familiar melodies from
this ballet, but as you indirectly pointed out, the full ballet has more
music than is commonly heard, and I found the variety of themes (and
their beauty) remarkable. It was a nice (taped) performance, too, don't
know whose.
Which road are you suggesting, Anna? Music for ballet? Tchaikovsky?
Local productions of famous Christmas works?
I must confess my favorite music composed for dance is probably "The
Catherine Wheel," David Byrne for Twyla Tharp, but that's sorta by
default. Not a big classical ballet fan, I'm afraid! More reason why I
was disappointed in the music on Saturday - I wasn't loving the dance
that much.
> But back to reality -- this is typical of the result we have come to in the
> current cost of the arts. Most local ballet schools will mount a holiday
> production of The Nutcracker because it is such popular fare at this time of
> year, the kids love it, it gives the young dancers something to shine in and
> it helps to promote their dance businesses. Yet unless possessing extensive
> grant funding to foot the costs, few can afford a live orchestra.
This was the case : it was a local ballet, many strudents were onstage
and performed wonderfully.
> And, the
> taped copies are usually an amateur effort administered by people who know
> less than nothing about sound systems, much less about good sound. In other
> words, they can't afford professional sound technicians either (even assuming
> they could find one who wasn't stone deaf, anyway).
I think the latter was the case : Someone from Something Studio got
program credit.
> I speak from personal
> experience when I tell you that these productions are largely the work of
> volunteers, and the artistic directors have to pretty much work with what they
> have given to them.
>
> So, Jeremy, since you undoubtedly found other pleasurable merit in the event,
Well, see my food review below.
> why don't you volunteer to assist with next year's production and see to it
> that the music reproduction is worthy of the effort? It might be fun, not to
> mention very rewarding as well as enlightening!
Good suggestion BUT : it was presented at a college auditorium, I expect
that I'd be impinging on someones turf or worse, acing a student worker
out of a job if I did so. Also why I didn't try to complain to someone :
they'd either be a volunteer doing the best they can, or a fixture who
does it the way he always does it.
Weak excuses perhaps. I'll mull it over.
My five year old daughter was rapt (through the middle of the second
act, when most grownups got fidgety too) so I consider it a successful
evening. Decent punch, and very good cookies, at the reception.
- -j
- --
=====================================
Jeremy Epstein .... jepstein@shwd.com
=====================================
=========================================================================
From: Dave Stagner <dstagner@icarus.net>
Subject: Re: Bad Playback
Date: Mon, 14 Dec 1998 16:52:54 -0600 (CST)
Source: Sound Digest Archive v01.n538
On Mon, 14 Dec 1998, Ken Dangerfield wrote:
> On 14 Dec 98 Jeremy Epstein said:
>
> > My five year old daughter was rapt (through the middle of the second
> > act, when most grownups got fidgety too) so I consider it a
> > successful evening. Decent punch, and very good cookies, at the
> > reception.
>
> Which is wonderful and makes the rest of it pale by comparison.
Heh. The other day (after getting my system in fairly decent shape again,
thanks to a new power supply for the DAC), i put on "The Magic Flute" for
the kids. My daughter the audiophile loved it. Her brother hated it, and
kept demanding to listen to Sesame Street. Eventually, he fell asleep
during an aria. Typical. :}
- -dave
Practice beautiful randomness and act kind of senseless.
<dstagner@icarus.net>
=========================================================================
From: AnnaLogg@aol.com
Subject: Re: Bad Playback
Date: Mon, 14 Dec 1998 16:58:45 EST
Source: Sound Digest Archive v01.n538
In a message dated 98-12-14 15:53:35 EST, jepstein@shwd.com writes:
> Oh, no, one could hardly have missed the more familiar melodies from
> this ballet, but as you indirectly pointed out, the full ballet has more
> music than is commonly heard, and I found the variety of themes (and
> their beauty) remarkable. It was a nice (taped) performance, too, don't
> know whose.
>
> Which road are you suggesting, Anna? Music for ballet? Tchaikovsky?
> Local productions of famous Christmas works?
Music for classical ballet in general, but specifically Tchaikovsky -- that
is, if you have not heard the full scores for Sleeping Beauty and/or Swan
Lake, for example. Also not to be left out, but of a much different flavor,
are the big Stravinsky works, "The Firebird" and "Rite Of Spring." (Try
*those* on your Wurlitzers, guys!) There is much, much more in the ballet
realm, and it is usually well-recorded and orchestrally both lush and
viscerally dynamic in a way that no other music quite matches, with the
possible exception of grand opera.
As for The Nutcracker, growing up I too heard only the suite, on records,
until I attended my first production by the New York City Ballet under the
direction of George Balanchine back in the early '60's. I recall being
especially bowled over by the music of the christmas tree scene (not to
mention the scenery effects) and then smitten by the Waltz of the Snowflakes
with it's hauntingly beautiful choral overlay (which so magically suggests the
soughing of the wind through the pine trees!), together with the whirling snow
that proceeded to fall more and more heavily as the dance progressed. It was,
to me, the ultimate in fantasy. No amount of filmed "special effects" can
quite compare to the magical impact of a well-done stage production.
For nearly 20 years after that, I never missed a NYC Ballet season, and
enjoyed watching costume and choreographic changes and refinements over the
ensuing years. It never failed to work it's magic on the child within.
If you can find an LP of it (and it's fairly common) I recommend the
Ansermet/Suisse Romande on London, a 2-record set, which I think has a special
theatricality. Otherwise, Dorati did it for Mercury, which would be my second
choice. But there are many others, and none really bad.
>
> I must confess my favorite music composed for dance is probably "The
> Catherine Wheel," David Byrne for Twyla Tharp, but that's sorta by
> default. Not a big classical ballet fan, I'm afraid! More reason why I
> was disappointed in the music on Saturday - I wasn't loving the dance
> that much.
>
Well, beauty is in the eye of the beholder. Just remember that contemporary
dance has its roots in classical movement and training. It is perhaps the most
interesting art form because prior to the advent of film, it survived via
tradition and legacy. Imagine, these great huge ballets being preserved only
through direct handing down from dancer to dancer as they evolved from
performer to teacher. If only we had a film record of that first Swan Lake or
that first Rite Of Spring (both of which were horrendously castigated by the
critics of the day)! If only we had a film record of the original choreography
of these 19th century masterpieces, for as you might expect, much has been
lost through the reliance on memory. Indeed, this is why the defection of
Nureyev was of such cultural importance to western dance -- he brought with
him a wealth of schooling and knowledge of classical choreographic tradition
that had not been seen outside Russia for many decades.
Getting back to Piotr Ilyitch for just a moment, it might interest you to know
that all that glorious music was composed to fit the choreography already
devised by the reigning choreographer, Petipa, not the other way around!
Yes, dance -- all of dance -- has a colorful and interesting history . . .
Well, forgive me my passion here. (Just don't anybody mention *opera*
<gasp!!>)
Happy holidays,
Valerie Ann(a)
=========================================================================
From: Kalman Rubinson <kr4@is2.nyu.edu>
Subject: Re: Bad Playback
Date: Mon, 14 Dec 1998 17:49:45 -0500 (EST)
Source: Sound Digest Archive v01.n538
On Mon, 14 Dec 1998 AnnaLogg@aol.com wrote:
> Music for classical ballet in general, but specifically Tchaikovsky -- that
> is, if you have not heard the full scores for Sleeping Beauty and/or Swan
> Lake, for example. Also not to be left out, but of a much different flavor,
> are the big Stravinsky works, "The Firebird" and "Rite Of Spring." (Try
> *those* on your Wurlitzers, guys!) There is much, much more in the ballet
> realm, and it is usually well-recorded and orchestrally both lush and
> viscerally dynamic in a way that no other music quite matches, with the
> possible exception of grand opera.
OK. Let me put in a suggestion for Prokofiev's Romeo and
Juliet (Maazel, Cleveland).
Kal
=========================================================================
From: AnnaLogg@aol.com
Subject: Re: Bad Playback
Date: Mon, 14 Dec 1998 18:25:39 EST
Source: Sound Digest Archive v01.n538
In a message dated 98-12-14 17:49:52 EST, kr4@is2.nyu.edu writes:
> OK. Let me put in a suggestion for Prokofiev's Romeo and
> Juliet (Maazel, Cleveland).
>
Yes!!! Breathtaking dramatic imagery and the same kind of evocative orchestral
depth and color as, say, Scheherezade. Plus melodies to tear your heart out .
. .
Happy holidays,
Valerie Ann(a)
=========================================================================
From: rlahlum@juno.com (Ross J Lahlum)
Subject: Re: Bad Playback
Date: Mon, 14 Dec 1998 22:37:33 -0600
Source: Sound Digest Archive v01.n539
That reminds me of my first recording of the Nutcracker -
William Steinberg & Pittsburgh on Command Classics
(1967 "audiophile" 35 mm recording). Finally found it & gave it
a relisten after many years. Kind of disappointing compared to
the records I think sound good now, since I must have worn it
out the first year on my kid-hi-fi BSR. Wish I could find a really good
copy.
But for me the magic of the piece was planted in my soul
at the tempos Steinberg chose, and any other version I hear (and I've
gathered 5 or 6 other interpretations over the years of binges at used
record stores, garage sales & friends of the library sales) no matter how
good, leaves me wishing it had been done Steinberg's way because that's
the way my mind plays it back to me. Even if it's not the critics'
definitive
version, it's the quickest route for me to get to feeling like a kid at
Christmas.
- -RL
On Mon, 14 Dec 1998 13:23:14 -0800 "Ken Dangerfield"
<bpyakd@mail.island.net> writes:
>On 14 Dec 98 Jeremy Epstein said:
>
>> My five year old daughter was rapt (through the middle of the
>second
>> act, when most grownups got fidgety too) so I consider it a
>> successful evening. Decent punch, and very good cookies, at the
>> reception.
>
>Which is wonderful and makes the rest of it pale by comparison.
>
>Regards,
>Ken Dangerfield
>
___________________________________________________________________
You don't need to buy Internet access to use free Internet e-mail.
Get completely free e-mail from Juno at http://www.juno.com/getjuno.html
or call Juno at (800) 654-JUNO [654-5866]
=========================================================================
From: Kalman Rubinson <kr4@is2.nyu.edu>
Subject: Re: Bad Playback
Date: Tue, 15 Dec 1998 09:17:40 -0500 (EST)
Source: Sound Digest Archive v01.n539
On Mon, 14 Dec 1998, Ross J Lahlum wrote:
> But for me the magic of the piece was planted in my soul
> at the tempos Steinberg chose, and any other version I hear (and I've
> gathered 5 or 6 other interpretations over the years of binges at used
> record stores, garage sales & friends of the library sales) no matter how
> good, leaves me wishing it had been done Steinberg's way because that's
> the way my mind plays it back to me. Even if it's not the critics'
> definitive
> version, it's the quickest route for me to get to feeling like a kid at
> Christmas.
Isn't it amazing how we are imprinted by an early exposure?
I have many such connections to performances that I now
accept as far from optimum but which, nonetheless, are among
my favorites because they are the way I learned the piece.
Kal
=========================================================================
From: "Eric Weitzman" <eweitzman@acm.org>
Subject: balance pot for PP amp with shared cathode resistor?
Date: Sun, 11 Oct 1998 21:56:54 -0700
Source: Sound Digest Archive v01.n450
I have a PP 6BQ5 amp that uses cathode bias. It has a tertiary winding
on the OPT in the cathode circuit providing feedback, and a 130 ohm (3
watt) cathode resistor bypassed by a 25uF cap on the center tap of
this winding providing the bias.
+----------Cathode of tube 1
|
+-)||
130 )||
GND-+--R--+-----)||
| | )||
+--C--+ +-)||
25 |
+----------Cathode of tube 2
How can I modify this circuit so that I can adjust the bias
of both tubes with a single pot? I bet it can't be done...
If I was to remove the tertiary winding from the circuit (and provide
feedback off of the secondary winding) and put a balance pot as shown
below, how would I calculate the bypass cap(s)? 25uF? 50uF? 12.5uF?
GND----C------+----------Cathode of tube 1
|
\
120 /
GND----R----->\ 20 ohm pot
/
\
|
GND----C------+----------Cathode of tube 2
Finally, if I keep the R of the pot low, I can use a cheap cermet
trimmer with a low power rating. Is using such a device going to
hurt the sound? I have four of these output stages and so I'd like
to keep the number and cost of the pots down.
Thanks,
- -Eric
=========================================================================
From: peterca@ento.csiro.au
Subject: Re: balance pot for PP amp with shared cathode resistor?
Date: Tue, 13 Oct 1998 10:14:52 +1000 (EST)
Source: Sound Digest Archive v01.n451
>I have a PP 6BQ5 amp that uses cathode bias. It has a tertiary winding
>on the OPT in the cathode circuit providing feedback, and a 130 ohm (3
>watt) cathode resistor bypassed by a 25uF cap on the center tap of
>this winding providing the bias.
>
>
> +----------Cathode of tube 1
> |
> +-)||
> 130 )||
>GND-+--R--+-----)||
> | | )||
> +--C--+ +-)||
> 25 |
> +----------Cathode of tube 2
>
>How can I modify this circuit so that I can adjust the bias
>of both tubes with a single pot? I bet it can't be done...
If the center tap of the actual tertiary winding is accessable (ie. you
have a loop of the wire or two wires coming out of the transformer) I would
cut the wire to get the two halves of the winding separate. Then I would
put a 260 ohm/2W resistor (IE 2x130ohm) from each one to ground and bypass
both with caps. With no other changes to the circuit you will get
automatic self bias. DC feedback will keep the DC balanced in the
transformer. This might be an improvement in itself if there are any
significant differences between the PP pairs now. This keeps your
modifications simple and cheap because the biasing, B+ and feedback
arrangements are unaltered, just better balanced for DC. The only hitch
would be whether you have room to accomodate two resistors and caps rather
than one of each.
Dr. Peter Campbell (peterca@ento.csiro.au)
Div. Entomology, C.S.I.R.O. Ph.61-2-62464053 or -62464158 (w)
Box 1700 Canberra A.C.T. 2601 61-2-62516213 (h)
Australia 61-2-62464173 (fax)
=========================================================================
From: Paul Joppa <pdj@ISDNseattle.net>
Subject: Re: balance pot for PP amp with shared cathode resistor?
Date: Mon, 12 Oct 1998 21:25:52 -0700
Source: Sound Digest Archive v01.n452
Can't pass this one up; I've fooled with a few PP BQ5s in the old
days...
Eric Weitzman wrote:
>
> I have a PP 6BQ5 amp that uses cathode bias. It has a tertiary winding
> on the OPT in the cathode circuit providing feedback, and a 130 ohm (3
> watt) cathode resistor bypassed by a 25uF cap on the center tap of
> this winding providing the bias.
>
> +----------Cathode of tube 1
> |
> +-)||
> 130 )||
> GND-+--R--+-----)||
> | | )||
> +--C--+ +-)||
> 25 |
> +----------Cathode of tube 2
>
> How can I modify this circuit so that I can adjust the bias
> of both tubes with a single pot? I bet it can't be done...
Step one: before you do anything else, replace that wimpy 3-w
resistor. Every 6BQ5 amp I've ever seen that was not working, was not
working because the cheap low-wattage cathode resistor had fried
itself. SE, PP, low-fi, hi-fi, or guitar, doesn't matter - it was a
cheap tube, made for cheap circuits and they used cheap parts. (OK, I
exaggerate a little - but I've seen it an awful lot of times!)
Step two: Look at a Williamson circuit. The original, I mean. It shows
you how to do this. Don't know what you were betting, but you lost!
:^) The Williamson also offers a separate adjustment for total
current as well as current balance.
> If I was to remove the tertiary winding from the circuit (and provide
> feedback off of the secondary winding) and put a balance pot as shown
> below, how would I calculate the bypass cap(s)? 25uF? 50uF? 12.5uF?
>
> GND----C------+----------Cathode of tube 1
> |
> \
> 120 /
> GND----R----->\ 20 ohm pot
> /
> \
> |
> GND----C------+----------Cathode of tube 2
Is this in pentode mode or triode mode? RDH4 has a method for
calculating cathode bypass, but it depends on the circuit. Triode caps
are always pretty close to twice what you'd think from the cathode
resistor alone, but pentodes are as much as 13 times I think (didn't
check - too lazy tonight). In either case, I doubt that the 25uF job
did much at low frequencies ... speaking of which, George Wright has
suggested in a similar situation that the two cathodes could be tied
together with a small cap - 1 uF or so - to improve balance at high
frequencies where the 'lytics are likely not performing well.
> Finally, if I keep the R of the pot low, I can use a cheap cermet
> trimmer with a low power rating. Is using such a device going to
> hurt the sound? I have four of these output stages and so I'd like
> to keep the number and cost of the pots down.
See above comments about power ratings.
- -Paul Joppa
=========================================================================
From: Ishmael349@aol.com
Subject: Re: Ban drinking in public places?
Date: Tue, 12 Jan 1999 09:31:16 EST
Source: Sound Digest Archive v01.n570
Thank you. The real issue here is too many people seem anxious to force other
people to suffer as long as they do not have to. I say you guys have
seriously limited my personal pleasure by allowing smoking to banned in
restaurants and airplanes but are not willing to give up dring in public
places to cut down on the national death toll. If that ain't hipocracy -
what is?
HR
=========================================================================
From: "David B. Klein" <dklein@microtec.net>
Subject: Re: Ban drinking in public places?
Date: Tue, 12 Jan 1999 16:18:36
Source: Sound Digest Archive v01.n570
A 09:31 AM 1/12/99 EST, Ishmael349@aol.com a écrit :
>Thank you. The real issue here is too many people seem anxious to force
other
>people to suffer as long as they do not have to. I say you guys have
>seriously limited my personal pleasure by allowing smoking to banned in
>restaurants and airplanes but are not willing to give up dring in public
>places to cut down on the national death toll. If that ain't hipocracy -
>what is?
>
>HR
>
>
One important difference between tobacco and alcohol is that moderate
alcohol use is beneficial, whereas no amount of tobacco use confers
benefits. Moderate drinkers outlive teetotallers, whereas any amount of
smoking reduces life expectancy. Regarding public drinking leading to road
accidents, the analogy is a poor one. There are blood alcohol limits for
drivers, and sanctions against those who are caught violating these.
Another important difference is that moderate drinking in a public place
does not infringe on my rights, whereas smoking does. There is no "passive
drinking" that corresponds to "passive smoking."
dbk
=========================================================================
From: Joe Pledger <doodle@navicom.com>
Subject: Re: Ban drinking in public places?
Date: Tue, 12 Jan 1999 23:38:09 -0800
Source: Sound Digest Archive v01.n571
Sellek, Grant (TSA) wrote:
>
> Date: Tue, 12 Jan 1999 16:18:36
> From: "David B. Klein" <dklein@microtec.net>
> Subject: Re: Ban drinking in public places?
>
> Moderate drinkers outlive teetotallers, whereas any amount of
> smoking reduces life expectancy.
>
> --------end quote-----------
>
> As I recall, the studies that came to the above conclusion about alcohol
> were widely publicised for years (need I mention by whom?), before follow-up
> studies showed that the "teetotaller" group included reformed alcoholics,
> which totally biased the result. When the AA types were taken out of the
> teetotaller groups, the result was reversed.
>
> Further studies have since been undertaken to demonstrate that moderate
> drinking has no effect on health (need I mention by whom?).
>
> At some point I start to walk away from arguments (and that is what they
> are, not discussions) about statistical studies.
>
> Grant
>
> Grant Sellek
> Adelaide, Australia
> grant.sellek@roads.sa.gov.au
Well,
The last time I was in Spain, entered a resturant and they plunked down
an unmarked btl of red (no water) without asking, and gave me a menu!
One glass of red per day is fine! Trouble is one tends to do that and go
on...and on..Ah! Spain!
Regards,
M513S
=========================================================================
From: "David B. Klein" <dklein@microtec.net>
Subject: Re: Ban drinking in public places?
Date: Wed, 13 Jan 1999 04:20:20 -0500
Source: Sound Digest Archive v01.n571
David Barnett wrote:
>
> On Wed, 13 Jan 1999 07:50:20 +0000 (BST), Simon Busbridge
> <S.C.Busbridge@bton.ac.uk> wrote:
>
> >What has this got to do with hi-fi?
>
> That one's easy -- smoking will damage the panels in my old QUAD
> Electrostatic Loudspeakers, but I can drink in the same room with them
> and they'll be safe unless I trip over them.... <G>
>
From another perspective, the ESLs will probably precipitate smoke
particles out of the air (to their detriment, however).
Cheers,
David
=========================================================================
From: Simon Busbridge <S.C.Busbridge@bton.ac.uk>
Subject: Re: Ban drinking in public places?
Date: Wed, 13 Jan 1999 07:50:20 +0000 (BST)
Source: Sound Digest Archive v01.n571
What has this got to do with hi-fi?
Dr Simon Busbridge
School of Engineering
University of Brighton
Lewes Road
Moulsecoomb
Brighton BN2 4GJ
UNITED KINGDOM
Tel: 0044 (0)1273 642542
Fax: 0044 (0)1273 642327/642301
e-mail: s.c.busbridge@bton.ac.uk, scbusbridge@hotmail.com
On Tue, 12 Jan 1999 Ishmael349@aol.com wrote:
> Thank you. The real issue here is too many people seem anxious to force other
> people to suffer as long as they do not have to. I say you guys have
> seriously limited my personal pleasure by allowing smoking to banned in
> restaurants and airplanes but are not willing to give up dring in public
> places to cut down on the national death toll. If that ain't hipocracy -
> what is?
>
> HR
>
=========================================================================
From: davidbarnett@aristotle.net (David Barnett)
Subject: Re: Ban drinking in public places?
Date: Wed, 13 Jan 1999 08:14:20 GMT
Source: Sound Digest Archive v01.n571
On Wed, 13 Jan 1999 07:50:20 +0000 (BST), Simon Busbridge
<S.C.Busbridge@bton.ac.uk> wrote:
>What has this got to do with hi-fi?
That one's easy -- smoking will damage the panels in my old QUAD
Electrostatic Loudspeakers, but I can drink in the same room with them
and they'll be safe unless I trip over them.... <G>
- --dnb
=========================================================================
From: "Sellek, Grant (TSA)" <Grant.Sellek@roads.sa.gov.au>
Subject: Ban drinking in public places?
Date: Wed, 13 Jan 1999 16:31:49 +1030
Source: Sound Digest Archive v01.n571
Date: Tue, 12 Jan 1999 16:18:36
From: "David B. Klein" <dklein@microtec.net>
Subject: Re: Ban drinking in public places?
Moderate drinkers outlive teetotallers, whereas any amount of
smoking reduces life expectancy.
- --------end quote-----------
As I recall, the studies that came to the above conclusion about alcohol
were widely publicised for years (need I mention by whom?), before follow-up
studies showed that the "teetotaller" group included reformed alcoholics,
which totally biased the result. When the AA types were taken out of the
teetotaller groups, the result was reversed.
Further studies have since been undertaken to demonstrate that moderate
drinking has no effect on health (need I mention by whom?).
At some point I start to walk away from arguments (and that is what they
are, not discussions) about statistical studies.
Grant
Grant Sellek
Adelaide, Australia
grant.sellek@roads.sa.gov.au
=========================================================================
From: evaguido <EvaGuido@iaehv.nl>
Subject: Re: Ban drinking in public places?
Date: Wed, 13 Jan 1999 17:01:27 +0100
Source: Sound Digest Archive v01.n572
please discuss without involving joes
Guido
At 09:31 12-1-99 EST, Ishmael349@aol.com wrote:
>Thank you. The real issue here is too many people seem anxious to force
other
>people to suffer as long as they do not have to. I say you guys have
>seriously limited my personal pleasure by allowing smoking to banned in
>restaurants and airplanes but are not willing to give up dring in public
>places to cut down on the national death toll. If that ain't hipocracy -
>what is?
>
>HR
>
>
=========================================================================
From: Ishmael349@aol.com
Subject: Re: Ban drinking in restaurants?
Date: Mon, 11 Jan 1999 15:47:06 EST
Source: Sound Digest Archive v01.n567
If I smoke a cigerette after dinner it will not be the cause of me hitting a
school child with my car on the way home? The wine I had with dinner will.
Which of you non-smokers are ready to ban drinking in restaurants? I
personally would prefer to not smell alcohol while I eat. Is that reason
enough for you to not have wine with your meal? Please, tell me your concern
for the national health and welfare is great enough for you to give up
alcohol.
HR
=========================================================================
From: davidbarnett@aristotle.net (David Barnett)
Subject: Re: Ban drinking in restaurants?
Date: Tue, 12 Jan 1999 19:53:11 GMT
Source: Sound Digest Archive v01.n570
On Mon, 11 Jan 1999 15:47:06 EST, Ishmael349@aol.com wrote:
>If I smoke a cigerette after dinner it will not be the cause of me hitting a
>school child with my car on the way home?
Most people can take one drink and stop. No one smokes one cigarette.
Alcoholics are a minority of the total number of people who drink, all
cigarette smokers are addicts.
- --dnb
=========================================================================
From: Jeremy Epstein <jepstein@shwd.com>
Subject: Bantying About Opinion Etc.
Date: Mon, 30 Nov 1998 15:56:52 -0500
Source: Sound Digest Archive v01.n510
Without entering into a whole lotta debate over pseudoscience,
charlatanism, shamanism and the like, I _would_ like to discuss the
place I see for "I like this better than that" types of debate.
I'm a busy guy when I'm at home. I've got a wife (talk about a full-time
job!) and a kid, and they both get a little huffy when I hide in the
basement sniffing solder fumes for hours on end, all weekend, every
night. Trust me, I know this from experience. So I have to leave SOME of
the xPerimentation to my esteemed collegues. I try to hold up my end by
being as helpful as I can around here, but as a general rule, I owe you
one. And I will probably never catch up.
Now take a guy like Slagle, who tries more tweaks in a day than I do in
a year. He has a setup whereby he can try this, that or the other thing
just by twisting a Variac and moving a clip lead. (I will point out that
he has learned nothing whatsoever about shielding or layout or UL
approval, those of you who have visited him will know what I'm talking
about.)
A guy like me has no choice but to listen to a guy like him. He says,
"low DCR in the power supply," or "try the mercury rectifiers, at worst
they look tres cool, at best they sound great," and he has been there
and done that. Is he oversimplifying? Most likely. Will I have fun
building and listening to equipment using his design principles and
prejudices? Definitely. Will I ever design and build gear for a living?
Will I discover the Rosetta Stone of Audio Reproduction? Um, doubtful.
I still think all the Joes are really cool, though. Myself included.
Even if some of us are totally FOS, myself included.
- -j
- --
=====================================
Jeremy Epstein .... jepstein@shwd.com
=====================================
=========================================================================
From: "Doc B." <bottlehead@silverlink.net>
Subject: Bantying about opinion instead of listening and learning for ourselves
Date: Mon, 30 Nov 1998 09:15:46 -0800
Source: Sound Digest Archive v01.n509
The very best reason to buy Magnaquest is that they are
>cheaper than Tango or Tamura, certainly not better. Just look at the band
width
>for starters.
The fact that MagneQuest products are less expensive for equal or better
performance than the two very good, quite different competitive products
mentioned here is indeed a very good reason to consider their purchase, but
hardly the only one.
Do, look at the bandwidth, the power bandwidth. It will become apparent that
the MagneQuest transformers exhibit excellent performance at low
frequencies.
It's very interesting to attend one of Mike L.'s talks at VSAC. The question
always comes up "What about the importance of frequency response
measurements? "
As Mike points out, this is really about item number 20 on the list for
determination of the best transformer for a given application.
It is much more likely that measured inductance at low frequencies and
higher power levels will come to play. If you must buy based on what are, as
Lynn points out, basically rather gross measurements, then at least use as
many different specifications as possible to make a decision, with
inductance as one of the more important factors.
Also, consider the manufacturer's rationale in their selection of materials.
Is it best to use permalloy in a conventional airgapped transformer,
allowing direct coupling to the plate of the output tube, but where where
its high permeability is hampered by the problem of saturation from DC, or
in an interleaved transformer designed for parallel feed, where the tube is
cap coupled, but the permalloy is used to its best advantage?
Is it better to pot a transformer, which is indeed quite attractive and may
help to reduce "singing", at the expense of risking distortion of the
laminations by the use of potting material that does not penetrate as well
as some waxes and varnishes, and adds more insulating materials of perhaps
questionable DA and DF to potentially color the sound?
And if you must use frequency response as a factor in your choice of
transformers, perhaps because this is a measurement easily understood not
only by experienced designers, but also by the cool new folks who are
swelling the bottlehead ranks lately, please do consider that manufacturers
published response figures vary from +- 1 dB to +- 3 dB, which makes side by
side comparisons of these figures fairly useless.
I agree that the idea of Mike feeling the need to redesign any competitor's
current production is indeed quite silly, and I suggest that Lynn's point
that designers would be compelled to charge for their time if asked to work
on an existing design was pulled quite far out of context here.
And as always, I suggest that using your own ears is the only true way to
determine what works for you.
Doc B.
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From: "Doc B." <bottlehead@silverlink.net>
Subject: Re: Bantying about opinion instead of listening and learning for ourselves
Date: Mon, 30 Nov 1998 12:48:52 -0800
Source: Sound Digest Archive v01.n510
>Hi Doc,
>
>I agree absolutely that we should choose on the basis of our experince
which is
>exactly what I did, and chose Tangos.
This is excellent, you have listened and made a choice that pleases you. But
why the knee jerk reaction to the supposition posted by Lynn? He did not say
that either of those products *needed* to be redesigned, he was just using
them for the sake of example to make a different point, suggesting that
anyone who would ask for one manufacturer to modify another manufacturer's
product should be prepared to pay for the designer's time.
He obviously made a choice of brands which rubbed you the wrong way. Why you
feel compelled to turn this into your own partisan diatribe is your own
business, I guess.
But hell, don't be surprised that I defend my turf, that's my job.
>
>There are let's face it partisans on this list of manufacturers who
disguise
>their partisanship in supposedly objective language.
My post was certainly not objective. I can't imagine why you took it that
way. I am the largest MagneQuest distributor because I believe it is an
excellent product, and I have never disguised this fact. If I posted in such
a manner as to make it appear objective, perhaps you have mistaken my
concern to not bash a competitive product in a crude manner for some sort of
patronizing tone.
Also some of these
>partisans on this list manufacture amplifiers for commerical sale using one
>brand of transformer or another. So, I hardly think it is objective to say
that
>Tango or Tamura transformers are in need of redesign by Mr LeFevre who by
all
>accounts has only been making transformeres for a few years whereas the
Japanse
>brands have been at it for many decades!
To begin with Mike's archives go back to 1934 and includes designs from
WE,Peerless, Acrosound,Dynaco, Freed, Triad, etc.
Secondly, Mike's capabilities show in his product and innovation. Take
parallel feed as a single example of a very creative, informed approach to
Mike's design qualifications.
Thirdly, every transformer that leaves MagneQuest has been handled by Mike
personally, a level of personalized quality control which is probably not
approached by the manufacturers you mention.
Lastly, nobody said Mike needed to redesign any competitor's product except
you.
>
>While I may have suggested bandwidth is a starting point for comparison, I
did
>not suggest in any way that it was the end of the story. On the other hand
you
>point to bass response amongst other supposed criteria in which Magnaquest
>transformers are supposed to exceed the capacities of the sorry Tango or
>Tamuras. Surely in itself bass is not even a particularly important
criterion? I
>say HF extension, you say bass. I know what I choose and why.
>
>My own opinion is that as a inbuilt crowd pleaser for audio illiterates,
bass
>response is a very successful selling point.
So now you are attempting to insult my customers? How childish! This kind of
opinionated blanket statement after suggesting that people compare technical
specs is evasive.
We're talking about a broad product line. There are MagneQuest transformers
that are -1dB at 140kHz. The RS series certainly matches the Tango products
in terms of top end response, and the small EXO series parallel feed
transformers are -1dB at 47 kHz and possess bass articulation superior to
any conventional air gapped SE transformers to boot.
Bass performance is indeed an important criteria, but not only in terms of
frequency response. The primary L of the transformer is critical to the
phase response of the bass. It is not a quantity issue, but rather an issue
of quality. It may well be that this is why Stereo Sound chose MagneQuest SE
and push pull transformers over the brands you have mentioned in their
subjective listening tests.
By the way, if you are using the response figures published in the
MagneQuest product literature as your guide, they are much more conservative
than what is actually measured. This is largely for the reason stated
before, Mike feels that frequency response specs are a small contributor to
what makes a transformer sound good.
But I suppose we are talking
>American "taste" (?)
I think here you have pretty much completely embarrased yourself. That is a
counterproductive way to make a point.
I would be interested in continuing this discussion on a technical level,
because I am quite confident it would be useful to joelist members. If you
would be interested in a competent technical discussion of useful criteria
for the selection of output transformers, please let me know, and I will ask
some of my associates to contribute to the discussion.
Doc B.
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From: "Doc B." <bottlehead@silverlink.net>
Subject: Re: Bantying about opinion instead of listening and learning for ourselves
Date: Mon, 30 Nov 1998 12:55:39 -0800
Source: Sound Digest Archive v01.n510
Why have you directed this to me?
Lynn is exceedingly competent, and able to answer your questions if you are
having trouble grasping any of his thoughts.
Doc B.
www.bottlehead.com
- -----Original Message-----
From: Mark Donen <soledadd@worldnet.att.net>
To: Doc B. <bottlehead@silverlink.net>
Cc: sound@deliverator.io.com <sound@deliverator.io.com>
Date: Monday, November 30, 1998 10:49 AM
Subject: Re: Bantying about opinion instead of listening and learning for
ourselves
>Dear Doc,
>
>I also note with interest how Mr. Olson has changed his views on horn
speakers
>since a long series of posts about a year ago. Naturally, I think it is
salutary
>that he has changed his mind, awakening so to speak from his dogmatic
slumber. I
>recall how it was argued at great length why horns cannot work well, by any
>objective measured criteria. Are we to believe that Messieurs Exemplar have
>overcome these problems, or that Mr. Olson has heard some good horns. My
>suspicion is that the measured problems Mr. Olson refers to persist and
that
>their horns just sound good. Bollocks to "objective" criteria!
>
>You have to correlate data to taste and measure the right thing. I am sure
Mr.
>Olson Ariel's measure great, but since he's enamored of the BBC house sound
I
>guess they wouldn't disturb a Brit granny slumping slowly sideways in a
>semiconscious stupor on her sofa listening to the Proms on Radio 3! There
are
>those who think Quad ESLs and LS3/5A are the greatest speakers in the world
and
>they are welcome. Just don't tell me there is no other way to build a
speaker.
>Let's not forget that only first order xo have a chance at passing a square
>wave, a criteria that has important subjective benefits, yet one that Mr.
Olson
>resolutely rejects on "objective" grounds in favor of higher order slopes.
>
>Mark
>
>
>
<