HDTenEightyP/NetNews huggingface dataset:
From: u-mwong%peruvian.utah.edu@cs.utah.edu (Michael Wong)
Subject: Need Specs/Opinions on Boston Acoustics 525v Center Speaker
Date: 28 Jul 92 21:32:45 MDT
Organization: University of Utah CS Dept
Distribution: usa

   I'm interested in getting a center channel for Pro-Logic, and I've
narrowed it down to the 525v center channel speaker.  But, I know very
little about its specs and what it has.  Could someone clue me in on
this model?  I noticed it has 2 5-1/4" woofers and a tweeter in the
center, but the woofer on the left side has all the dialogue while the 
woofer on the right side produces bass but no dialogue.  Is that the way 
this speaker is designed, or did I just listen to a speaker with a bad
woofer on the right side???

   I'm also interested in its frequency response and any features associated 
with the Boston Acoustics 525v!  I've heard a lot about this speaker and 
would appreciate if someone could tell me more about it!

-Mike
----------
Michael Wong 
u-mwong@peruvian.utah.edu
University of Utah
From: monta@image.mit.edu (Peter Monta)
Newsgroups: rec.audio
Subject: Re: 20 or 24 bit digital recording?
Date: 24 Jul 92 17:02:26 GMT
	<23292@alice.att.com> <1370@eagle.ukc.ac.uk>
Organization: MIT Advanced Television Research Program

In article <1370@eagle.ukc.ac.uk> wgd@ukc.ac.uk (W.G.Day) writes:

> In article <23292@alice.att.com> jj@alice.UUCP writes:
> > I now request your references

> Vinyl resolution reference:  apparently someone has performed measurements
> of the complex shape forming properties of polyvinyl and it comes out at
> around 16.5, I was also told that CD is 15.5 as you always have at worst
> a .5 bit error, which makes sense.  Shane...?

(This is a reference?)  First, the 0.5 bit error is likely a distorted
echo of the 0.5 LSB max error of a uniform quantizer; it does not
apply to SNR specs.  CD is 16-bit linear PCM, end of story.

Second, let's take a look at the 16.5 bit number.  (Disclaimer: I
don't know the LP system very well, so take this with a grain of
salt.)  16.5 bits means about 100,000 levels.  If we assume a
modulated groove in the vinyl with, say, 1mm maximum extent, then
we need to measure this to the tune of 0.01 um.  This would be
rather difficult even at DC, with interferometric measurement, and
over large areas (square mm).  To do this over small areas, at
multi-kHz rates, and with a piece of diamond scrabbling over the
surface, is hopeless; you would destroy the surface even if you could
press it to that accuracy in the first place.

Now if we rate the LP at 70 dB SNR at best (is this generous?), i.e.
11 bits, then the physical resolution is 0.5 um, which is at the
edge of reasonableness.  There remains piezo noise and distortion,
thermal noise in the preamp, etc. which I don't really know any
numbers for.

Peter Monta   monta@image.mit.edu
MIT Advanced Television Research Program
From: jj@alice.att.com (jj, curmudgeons for trvth in audio)
Newsgroups: rec.audio
Subject: Re: 20 or 24 bit digital recording?
Date: 23 Jul 92 16:08:25 GMT
Article-I.D.: alice.23292
Reply-To: jj@alice.UUCP (jj, curmudgeons for trvth in audio)
Organization: NJ State Home for Bewildered Terminals

In article <1353@eagle.ukc.ac.uk> wgd@ukc.ac.uk (Warren Day) writes:
>Current vinyl is apparently about twice the resolution of CD (assuming
>you've got a clean record, but we've talked about that). 
No, Warren, we haven't talked about that.  The best vinyl in the world
has a noise level well aove the quantizing noise level of a CD,
and in no way can in considered to have 'twice the resolution
of vinyl'.

Since you state otherwise in such an authoritive fashion, I now request your
references, controls, experimental data (you have to have measured noise
levels somewhere to do make the claim you make) and so on.

I find (having done the appropriate measurements many times over
many different systems) the statement that "lp has twice the
resolution of CD" utterly, hysterically laughable, in fact,
absurd and bordering on misrepresentation.


>16384 ohms +/- 5% is about 800 ohms error.  In a multi-bit player there
>are also resistors of 1 ohm, 2 ohm, ... , 256 ohm , 512 ohm , 1024 ohm.
>So the errors really corrupt the sound produced.
Warren, Warren, Warren, what do you think they use for resistors
in the DA convertor ladder in a CD player?  The whole point of
laser trimming and such is that (some) manufacturers reach about 15 bits
of accuracy with their 18 bit convertors (I'm referring to parallel,
not delta-sigma convertors), and they're getting better all the time.

If they used YOUR example, they couldn't get past 4.3 bits.
-- 
 Bush    *Copyright alice!jj 1992, all rights reserved, except transmission
   vs       *by USENET and like free facilities granted. Said permission is
 Clinton  --    *granted only for complete copies that include this notice.
 Just Say !NO!       *Use on pay-for-read services specifically disallowed.
Newsgroups: rec.audio.pro
From: bussey@meaddata.com (Greg Bussey)
Subject: speaker cabinet design software
Organization: Mead Data Central, Dayton OH
Date: Mon, 27 Jul 1992 11:25:32 GMT


A friend asked me to solicit the net for info. I know there was alot
of discussion not too long ago.

Please send me info on any design programs you are familiar with.

Thanks!


---------------------------------------------------------------------
- Greg Bussey                                  bussey@meaddata.com  -
- If you choose not to decide, you still have made a choice  (rush) -
---------------------------------------------------------------------
From: mbreen@sdacs.ucsd.edu (Michael Breen)
Newsgroups: rec.audio.pro
Subject: Soundproofing
Date: 27 Jul 92 23:29:17 GMT
Organization: University of California, San Diego
NNTP-Posting-Host: sdacs.ucsd.edu

I posted recently regarding 'soundproofing' an area of my garage.
Thanks to all who have gotten me this far.  Now I can ask 'better'
questions.  Let me set it up again:

I've got a corner of my rented garage I want to put a band in.  Pretty
good size PA, guitar, bass (electric), and drums.  I will probably allow
for some 'comfort' room, like a sofa, and/or some bookcases, etc.  The
room will be mostly for rehearsal, occasionally to record (roughly) to
a 4-track.  The space is about 10'x15' (I can get up to 15'x20', if I can
get enough material to 'soundproof' it).  The way I want to set it up,
it's two walls, one with a window, a concrete floor, and a slanted roof
with rafters.  The 'box' is completed by two 'imaginary' walls.  I have
a bunch of 'foam', stuff from hospital beds, about 4" thick with 'cones'
on one side. flat on the other. I also have a bit of 'professional'
acoustic-tile-stuff.  All told, it *might* cover two walls.  I can get to a
bunch of plywood, and will spend a little if I have too.

I am mostly interested in 'soundproofing' so the neighbors can't hear
me.  I'm only interested in the acoustic properties of the room as far
as it doesn't cost me anything.  Given that:

1) what are my biggest 'sound leak' problems?  I assume closed
windows made pretty good 'speakers' to the outside world.

2) where can I best utilize the foam/plywood/other materials?  One
of the existing walls faces my house, so it will be my last 'sound leak'
worry.  I thought of hanging plywood perpendicular off the rafters to
create the two non-existing walls, then covering them with foam.

3) How can I cut corners?  I'll probably get an old sofa, and I
understand that can act as a great bass sink.  I could also try to get
some thick curtains.  I have lots of books and mags.  I hear carpet
don't do squat (as with egg-cartons).

4) Is there any advantage to 'baffles' (panels covered with foam)
situated in front of bass sources, like the kick drum or bass amp?
Will this dampen the sound inside more than it's worth?  Is there a
better way?  I understand they are good for 'isolation' when you're 
recording a bunch of musicians in the same room.

Thanks ahead of time.  Any crazy ideas, past experiences, or general 
banter on the subject is cool with me, email or posted (damn, I'm 
easy!)

Michael K. Breen
singing and philosophizing
(and still only really worried about the neighbor in the back)
Newsgroups: rec.audio.pro
From: tchannon@black.demon.co.uk (Tim Channon)
Subject: INFORMATION WANTED ON ARCHIVING RECORDINGS ON A LONG 
Distribution: world
Organization: null
Date: Thu, 23 Jul 1992 01:21:12 +0000

> Yamaha has just released a CD recorder which produces discs playable on
> standard CD players.  This allows you to library about 60 minutes of audio
> in a permanent state which shouldn't really go out of date.
> 
> Other companies will most likely be releasing the same sort of equipment in
> the coming months.  Reviews of this model seem to be quite good.  It costs
> $15,000 I believe.  Get the May issue of Mix Magazine for a complete review.
> 
Yamaha have had various engines on the market and Gotham Audio of New York 
have used one of these as part of a red book compatible mastering system.

What is unusual about the new Yamaha? The Philips family of CDR has  been  on 
the market and selling well for some time now. This meets Orange book and Red 
book on fixup. (press a button and wait).

Full  length  73  minute disks are becoming available. Ordinary 63 min blanks 
seem to be selling for 15 to 20 sterling. (for comparison full  price  CD  is 
around 12 sterling in record stores)

CDR is circa 3500 stirling.

  TC. 
    E-mail: tchannon@black.demon.co.uk or tchannon@cix.compulink.co.uk
                                
Newsgroups: rec.audio.pro
From: eacj@theory.TC.Cornell.EDU (Julian Vrieslander)
Subject: Re: The Lindsay-Geyer Corporation is online
Organization: Cornell Theory Center
Date: Thu, 23 Jul 1992 15:04:27 GMT

In article <!bgm+_f.calving@netcom.com> calving@netcom.com (The Lindsay-Geyer Corp) writes:
>In article <1992Jul21.152510.14537@col.hp.com> friedman@col.hp.com (John Friedman) writes:
>>calving@netcom.com (The Lindsay-Geyer Corp) writes:
>>> The Lindsay-Geyer Corporation is on line.
>>
>>Okay.  I'll bite.  What exactly is "The Lindsay-Geyer Corporation?"
>
>The maker of the World's best-sounding mic and other audio cables. 
>With our mic cable, it doesn't sound like PA anymore.
>It sounds like face-to-face.

Isn't Lindsay-Geyer also the source for an audiophile cable that caused
a lot of controversy a year or two ago?  I don't follow these matters
very closely, but I recall seeing claims about how this stuff used
"highly magnetic" materials to achieve new performance levels.  I am sure
that some of the net-skeptics would enjoy reading a technical explanation
of the physical principles that give this cable its advantages.

Or alternatively, perhaps you can give a technical explanation of the
marketing principles used to sell such a product. ;-)

Note that I am not being totally cynical here - I am glad to see
manufacturers on the net, and if you can provide a real explanation for
the alleged superiority of your cables, I would be very interested in
reading it.
-- 
Julian Vrieslander 
Neurobiology & Behavior, Mudd Hall, Cornell University, Ithaca NY 14853    
INTERNET: eacj@theory.tc.cornell.edu     BITNET: eacj@crnlthry
UUCP: ..cornell!batcomputer!eacj
Newsgroups: rec.audio.pro
From: jay@cmn6.Stanford.EDU (Jay Kadis)
Subject: Re: AKG 414 - different models
Organization: DSO, Stanford University
Date: Thu, 23 Jul 92 22:38:26 GMT

In article <6948.2a6e9382@dcatla.uucp> duslt@dcatla.uucp writes:
> What is the difference between the ULS and TL models of the AKG 414?   
I've
> heard that the TL is better.  Why?
> 
> Lee Taylor
> Atlanta, GA
> duslt@dcatla.uucp


The ULS models have transformer outputs while the TLs use active  
electronics.  The main differences are high frequency linearity, which the  
TLs are supposed to improve, and some bass handling capability.  The ULS  
might actually be better if radiated noise is a problem, since they can be  
totally isolated due to the transformer output.  The ULS models don't  
sound bad, of course.

Jay Kadis
jay@ccrma.stanford.edu

Newsgroups: rec.audio.pro
From: tchannon@black.demon.co.uk (Tim Channon)
Subject: Uncorrected errors on digital transfer
Distribution: world
Organization: null
Date: Thu, 30 Jul 1992 23:40:30 +0000

Any uncorrected error at any point in a mastering chain may cause a hard 
coded error. I have a lot of anecdotal evidence that this is a common 
occurance and in my opinion can be responsible for some of the bad sounds 
which some of our 'golden ear' friends do not like about CD. On top of that 
there are replay errors on the CD which are yet again audible.

It is high time that the issue was fully addressed so what better than 
starting to shout about the problem.

Here is an example of the problem:
A recording is mastered on DAT. The recording is then digitally transfered to 
some other system. 
Unfortunately DAT (in common with all other media) does produce occasional 
uncorrectable errors. Now, if you listen to the DAT analog output you will 
probably hear nothing unusual because the DAT interpolates over the error -- 
** this is not true of the digital output ** where the sample will be flagged 
as unreliable but will _not_ be interpolated.
I know of no DAT that interpolates digital output or equipment which 
interpolates on digital input.
If you listen on equipment connected to the digital link you may hear bad 
noises.

I recently designed commercial equipment which happens as a side issue to 
indicate flagged errors on the digital link. Watching this is educational and 
even CD players can show a great deal of bad data being output.

A cure for some of this on CD is to clean the disk! Honest! 
The advice of 'do not touch the face of the disk' is good.

The transfer of material to a CD mastering plant on UMatic is a potential 
source of these errors. I have spoken to some plants (sic) and there is 
either no admitted knowledge of the problem or a policy is implemented. The 
policy seems to be to make a decision as to whether to reject the tape. I am 
unconvinced that all errors will be caught even if monitoring has taken place 
at the CD plant.
Then there is the matter of producing a UMatic tape containing perfect data.

  TC. 
    E-mail: tchannon@black.demon.co.uk or tchannon@cix.compulink.co.uk
From: tonyb@juliet.ll.mit.edu ( Tony Berke )
Newsgroups: rec.audio.pro
Subject: Re: Soundproofing
Date: 28 Jul 92 18:56:44 GMT
Organization: M.I.T. Lincoln Lab - Group 43

In article <1520sdINNb2@network.ucsd.edu> mbreen@sdacs.ucsd.edu (Michael Breen) writes:

   [...]

   I've got a corner of my rented garage I want to put a band in.  Pretty
   good size PA, guitar, bass (electric), and drums.  I will probably allow
   for some 'comfort' room, like a sofa, and/or some bookcases, etc.  The
   room will be mostly for rehearsal, occasionally to record (roughly) to
   a 4-track.  The space is about 10'x15' (I can get up to 15'x20', if I can
   get enough material to 'soundproof' it)...

If you really want to soundproof your room, foam on the walls isn't going
to do all that much by itself.  It might soak up the cymbals, but not much
else, I think.

What you need to do is build a "room within a room", ie a
free-standing box made of 2x4's and sheetrock.  This doesn't need to
cost too much -- 2x4's are a buck each, and sheetrock is pretty cheap
as well.  You then can stuff your bedfoam inbetween the outside and
inside walls (er, maybe not -- I'm sure that's a firecode violation.
A few inches of fiberglass will work well and won't cost too much).
This can give you a very big attenuation compared to just about any
other construction method.

If the above is out of the question, I supposed you might get away
with a couple of thick sheets of sheetrock applied directly onto the
garage walls and ceiling.  Make up a thick foam-lined plywood cover
for the window and come up with an airtight gasketing system.

Garage doors are sonic sieves, you'll need to do something very
serious to them, such as build a (removable) wall out of 2x4s and
sheetrock (both sides, preferable) in front of them, with some sort of
gasketing around the whole thing.  Barring that, a couple of sheets of
plywood, some bracing, and lots of gasketing, and foam between it and
the doors will help, but be far from optimal.  Real attenuation takes
mass, but just stopping air leaks can go a long way.

Also, pay attention to the eaves.  The garage might have soffit vents,
and even if it doesn't, many builders use 1/4" plywood in the soffit
panels.  If you sheetrock the ceiling sound won't be in a position to
leave via that route, but stuffing some fiberglass into the area might
be a good idea anyway.

Are you fully depressed yet?

Tony
Newsgroups: rec.audio.pro,rec.music.makers,rec.music.synth
From: jacob@max.cc.brandeis.edu ( )
Subject: recording choral monophonic music [?]
Organization: Brandeis University Math Department
Date: Thu, 23 Jul 1992 04:07:45 GMT

First I have a rather specific question: what's the typical set-up
for recording choral *monophonic* music (such as Gregorian Chant; as
opposed to polyphonic music a capella, i.e. w/o instruments, where
the choir is divided into sections that each sings its own line in
the polyphony; such are for example works by Josquin des Pres or Palestrina)

Basically what type of machine is used in recording choral monophonic music?
2-track, 4-track, 8-track or what? Also how are the choir and the mics usually
placed?

If it makes a difference whether the recording is made live (for example in
a church w/o any special accoustic insulation) or in studio consider that I've
asked the question for both...

                                 *
                               *   *

Second I have a more general question which is more in the style of a clari-
fication. Is it correct that multitrack recording (4-track and above) is only
used for popular music (like I've always thought until now that I've really
asked myself that question), or is it completely false? Again if it makes
a difference whether it's live or studio I'd be interested to hear the answer
for both.
Organization: The American University - University Computing Center
Date: Wednesday, 22 Jul 1992 11:10:02 EDT
From: Eric Ashman <EASHMAN@auvm.american.edu>
Newsgroups: rec.audio.pro
Subject: Re: INFORMATION WANTED ON ARCHIVING RECORDINGS ON A LONG TERM BASIS

Yamaha has just released a CD recorder which produces discs playable on
standard CD players.  This allows you to library about 60 minutes of audio
in a permanent state which shouldn't really go out of date.

Other companies will most likely be releasing the same sort of equipment in
the coming months.  Reviews of this model seem to be quite good.  It costs
$15,000 I believe.  Get the May issue of Mix Magazine for a complete review.

Eric Ashman, American University
Newsgroups: rec.audio.pro
From: kludge@grissom.larc.nasa.gov ( Scott Dorsey)
Subject: Re: Resurrecting Recordings
Organization: NASA Langley Research Center and Reptile Farm
Date: Thu, 30 Jul 1992 13:37:05 GMT

In article <1992Jul30.083054.8578@iccgcc.decnet.ab.com> ireland@iccgcc.decnet.ab.com writes:
>Resurrecting old recordings using digital technology has been going on for 
>a handful of years now. I believe the way its done is to sample in
>the record into memory. Then you put a little bit (of the song) at a time
>on your monitor. At this point you are looking at the music waveforms for
>a particular section. You then roll the mouse up to any high amplitude
>transients that look like they could be "pops", and then erase (or cut,
>or whatever) the peak, thus eliminating the pop. I suppose you would want
>to do a before and after comparison at this point to make sure you are 
>happy with the modification. 

There's a lot more than just click and pop supression.  The shellac recordings
had a lot of low-level noise (due to the filler that was used to polish the
steel needles and keep them fitting into the groove), and this is next to
impossible to remove with a click supression algorithm.  A noise gating 
system can do it, but also tends to be harsh on the low-level detail of the
music.

Also, dynamically switching between reading the right and the left groove
can help with a lot of the worst damage.  The Packburn systems do a very nice
job of this, probably better than any of the digital systems I have used.

It's also possible to use a nonlinear transform which is an inverse of the
cutter transfer function, to help reduce nonlinearities in the original
cutter.  Especially with acetates, which have very good preservation of the
cutter movements but were usually made with non-feedback cutters, this is
a good (if difficult to perform) use of digital systems.
--scott
From: robertj@tekgen.bv.tek.com (Robert Jaquiss)
Newsgroups: rec.audio.pro
Subject: INFORMATION WANTED ON ARCHIVING RECORDINGS ON A LONG TERM BASIS
Date: 21 Jul 92 21:36:38 GMT
Organization: Tektronix, Inc.


     I am looking for information and/or opinions on how to archive audio
recordings on a long term basis.  Thanks in advnace.

	Robert Jaquiss

Internet: robertj@tekgen.bv.tek.com
Xref: sparky rec.audio.pro:1339 rec.music.makers:8514 rec.music.synth:12664
From: sklower@diva.Berkeley.EDU (Keith Sklower)
Newsgroups: rec.audio.pro,rec.music.makers,rec.music.synth
Subject: Re: multitrack recordings of other than popular music
Date: 24 Jul 92 00:38:56 GMT
Organization: UC Berkeley TCS

In article <1992Jul23.040745.4793@news.cs.brandeis.edu> jacob@max.cc.brandeis.edu ( ) writes:
}Is it correct that multitrack recording (4-track and above) is only
}used for popular music ... ? ... if it makes
}a difference whether it's live or studio I'd be interested to hear the answer
}for both.

I saw a Harmonia Mundi recording being made during a live performance of
the Philharmonia Baroque.  They used 4 microphones (and I don't
think any of them were stereo mics).  (They all plugged into normal
3 element XLR connectors in the stage of Hertz Hall here)
(I vaguely recall hearing of them using their own 4 track recorder
which samples at a 50Khz rate).

Recordings of the San Francisco Symphony have been made by ``London''
records with many, many microphones fed into a multitrack recorders
sitting outside the building in a semi-rig.  (According to pictures
in the local paper).

I have it on reasonably good authority (only second hand from a
friend of the engineers involved) that some recordings in the
past 3 years of the Saint Louis symphony were recorded with
multiple microphones mixed live onto a 2-track DAT recorder.
(Originally a Sony PCM-2500 with the antialiasing filters
replaced by apogee filters, more recently a Sony PCM-2700.
The mutual friend was the guy who ``moded'' the DAT).
Newsgroups: rec.audio.pro,rec.music.makers,rec.music.synth
From: dan@cafws2.eng.uci.edu (Dan Harkless)
Newsgroups: rec.audio.pro
Subject: Re: Tascam MDR-8
Date: 23 Jul 92 16:53:09 GMT
Organization: University of California, Irvine

In article <3582@blue.cis.pitt.edu.UUCP> metlay@minerva.phyast.pitt.edu (metlay) writes:
>>Obviously VHS is less expensive but I've heard that 8mm is technically
>>superior, but that's at the level of a "rumour"... or thereabouts.
>
>Nope, it's the truth. VHS tape transports haul the tape out of the 
>machine and wrap it halfway around creation; 8mm is much gentler on
>the tape. It's also more compact, more solid in terms of tape winding
>and rewinding, and a commonly accepted standard for computer use (before
>the DAT came along, 8mm backup media were the most popular ones around;
>in fact, they may still be).

	Yes, Exabyte / 8mm backup drives are still the most popular, though
DAT / 4mm offers several advantages, including access / wind time.

------------------------------------------------------------------------------
| Dan Harkless                | "The sore in my soul                         |
| dan@cafws1.eng.uci.edu      |  The mark in my heart  ->  Front 242,        |
| dharkles@bonnie.ics.uci.edu |  Her acid reign..."        Tragedy >For You< |
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