HDTenEightyP/NetNews huggingface dataset:
From: lauson@en.ecn.purdue.edu (Patrick W Lauson)
Newsgroups: rec.audio
Subject: Re: How are speaker impedences specified?
Date: 2 Sep 92 02:31:40 GMT
Organization: Purdue University Engineering Computer Network

In article <78890@ut-emx.uucp> lihan@ccwf.cc.utexas.edu (Bruce G. Bostwick) writes:
>In article <1992Aug31.181551.9911@bmerh85.bnr.ca> shiv@bnr.ca (Shiv Naimpally) writes:
>>Impedance varies which is why you'll see impedance charts in some
>>magazine reviews. Normally the speaker literature will say something
>>to the effect that these speakers are nominally rated at 8 ohms (or
>>whatever).                            ^^^^^^^^^
>>
>>This means that on the impedance chart, this is the minimum impedance
>>the speakers have.
>
>Bear in mind, too, that the change in impedance with frequency isn't
>even roughly linear.  The voice coil is an inductor with a biased
>core, yes, but the cone is a mechanical component, and so is the air
>in and outside the box, and remember back emf?  That's right, the
>resonances and responses of the speaker, the box, and even the room to
>a tiny extent show up in the circuitry as 'backtalk' to the amp.  This
>means small (and sometimes large) peaks and dips in the impedance
>curve that change, often chaotically, when anything gets moved.

But my speakers have a perfectly flat impedance....

Zobel networks are a wonderful thing  :-)

-- 
------------------------------------------------------------------
| Pat Lawson                     :  Go Buckeyes!!!!!!            |
| lauson@en.ecn.purdue.edu       :    Scarlet and Gray Rules!!!! |
------------------------------------------------------------------
From: smith@eecg.toronto.edu (Michael B. Smith)
Newsgroups: rec.audio
Subject: Pro-Logic and Soundwave VR-2
Date: 2 Sep 92 01:19:09 GMT
Organization: Dept. of Electrical Engineering, University of Toronto

Just as many other articles in this news group have mentioned, I'm looking
for a Pro-Logic system of something higher in quality than an Atlanti,
Pioneer or Sony box.  The Yamaha A1000 would seem to do the trick, but
I wasn't overly impressed with the amps.  Of course, the chip set is
great!  So, one possibility is the Yamaha E1000 - I don't know for sure,
but is this basically an A1000 without the amps?  If so, this might be
a great ideal choice.

On the near horizon, I talked to a sales rep from NAD a few days ago,
and she claimed that NAD is bringing out a Pro-Logic decoder sometime
between Xmas and February called the NAD 900HT (could be wrong on
this).  Supposed to have minimal hall effects, and price around $1200
Canadian.  Couple this with the NAD 906 amp (6 by 30 Watts) and you've
got the makings of a good theatre.  Another possibility around the
corner is Harmon Kardon.  I heard rumours about a Pro-Logic receiver
soon, and maybe THX complient?  Source wasn't too reliable....

That's for the future, but what else exists now?  Sure, there's
a Lexison CP-2, or for those with the money, a CP-1.  The Fosgate
sounds nice, but $1600 for only Dolby Surround and no Pro-Logic??
Kinda pricey.  Have I missed any *GOOD* other possibilities for
out-board processors?  From looking around Toronto (Kromer, Brack,
Bay-Bloor, Kingsway-Audio, etc.) I haven't seen too much else.

My next question is to do with speakers.  I demo'ed a pair of
Soundwave VR-2's at Bay-Bloor radio on the weekkend hooked up to an
Adcom amp.  Beautiful smooth sound with excellent imaging.  The VR-1
was not quite as good (only one 8-inch woofer instead of two), but
also quite a steal at $1200 instead of $1700.  From looking though various
autio mags, I haven't found any reference to this American company, I
believe they are rather new, or its a new line from some other company.
Can anyone englighten me on this, or make any comments (good or bad)
on the VR-1s or VR-2s?

Thanks for any comments....

Michael

-- 
--
Michael B. Smith					UofT:(416)978-1652
smith@picton.eecg.toronto.edu				Electrical Engineering
--
Time is a great teacher, but unfortunately it kills all its pupils.
From: mo@sdf.lonestar.org (Mohit Goyal)
Newsgroups: rec.audio
Subject: Sony MD
Date: 29 Aug 92 16:25:32 GMT
Organization: sdf Public Access UNIX, Dallas--unrestricted free shell access

Hello.  Does Sony still plan on releasing the Mini-Disc this fall?

I haven't heard anything about this wonderful new format for months.
It was all over the news back in May.

Anyways, I am just curious as to when MD players will begin appearing
in stores, and blank and pre-recorded MD's will begin appearing in
stores also.

Thank you very much.
Newsgroups: rec.audio
From: rogn@telematikk.idt.unit.no (Egil Rognvik)
Subject: DIY - Subwoofer advice needed.
Organization: IDT
Date: Tue, 1 Sep 1992 09:38:17 GMT

I'm about to build a subwoofer (active filters, 5 amps, two-way satellites, 
mono subwoofer). Using "The Loudspeaker Design Cookbook" I get vented 
enclosures of about 60 litres and f3 of about 30 Hz. I've seen more "popular" 
formulaes, and they give about 73 litres and f3 about 27 Hz.
Should I use the cookbook or the formulaes?
I know I can extend the frequency respons by enlargening the box and tuning 
to a lower frequency, loosing transient response. Is this advisable? 
Is lowering the response from 30 to 25 Hz with a 0.5 dB dip, or to 20 Hz with
a 2 dB dip worth it?
I'm considering building a compound (isobarik) system to lower the distortion.
Will the lowered distortion be significant (will I notice the difference)?

The element is a Vifa 8" with Vas=185 litres, Qts=0.37, f3=26 Hz.

Any comments appreciated.


egil

* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Egil Rognvik                                * egilro@idt.unit.no
The Norwegian Institute of Technology       * rogn@telematikk.idt.unit.no
Division of Computer Systems and Telematics *
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
From: chrisc@gold.gvg.tek.com (Chris Christensen)
Newsgroups: rec.audio
Subject: Re: Bi-Amp vs. Bridged Bi-Wire
Date: 2 Sep 92 18:24:40 GMT
Organization: Grass Valley Group, Grass Valley, CA

In article <1992Sep1.212321.9571@jarvis.csri.toronto.edu> smith@eecg.toronto.edu (Michael B. Smith) writes:
>Assume that you have speakers that can be bi-amped and you happen to
>have four amps available.  One possible setup would be to bi-amp the
>speakers (i.e. one amp for the left tweeter, one amp for the left
>woofer, etc.).  Assuming that your amps can be bridged, it should also
>be easy to hook these speakers to be only bi-wired, but driven by
>a bridged amp.  This should provide about double to triple the power,
>so they'll probably be louder.  But, the big question is, which version
>should sound "better"?  What are the merits of bi-wiring?

IMHO.......(And in my personal experience) If you Bi-Amp with an electronic
crossover AND bypass the crossover portion (only) of the internal passive
crossover you would have better sound.  Any Zobel and or response
compensation networks should be kept in tact.  Failure to remove the
passive crossover will reduce the effectiveness of the change to
electronic b-amping (but not eliminate it,  it is still the best way
to go).

Oh and electronic bi-amping is far superior (if done correctly) to the
"other" style of bi-amping where one uses two amplifiers and feeds a
full range signal to both LF and HF sections.

>(This comes from planning a pro-logic system with 10 amps and 5
>speakers, and wondering what to do with all of the extra amps...)

I hope that you will be using some of the power for a subwoofer!
And I hope that you will be able to use a center channel speaker  that
is identical to the Left and Right speaker!

-- 
Chris Christensen                  The opinions I express are my own,
chrisc@gold.gvg.tek.com            and sometimes they are wrong!
916-478-3419 FAX 916-478-3887      After all, I *AM* only human.
From: joncon@hpcc01.corp.hp.com (Jon Connolly)
Date: Sat, 29 Aug 1992 02:27:18 GMT
Subject: Re: Acoustic studio monitors?
Organization: the HP Corporate notes server
Newsgroups: rec.audio

A friend bought some speakers from somebody in a van once. I don't know if
they were Acoustic or not but they actually turned out to be decent
speakers.  When you get down to it ( considering they do work at all)
$200 is not a whole lot of money to spend on speakers.  125 watts is
a reasonable amount of power and the one's I heard put out pretty 
well.  Obviously, you weren't looking to buy the ultimate in speaker
systems so I would say you didn't  get ripped off but got a decent
pair of speakers that if you decide you don't like you could always
use them when you're in your yard.  Throw 'em on the back porch when
you're kickin' it in the yard and you don't have to drag your Infinity's
or your JBLs or whatever it is you decided was the killer deal outside.

Just my opinion,  By the way, I think the speakers my buddy bought 
are still kicking after 8-10 years of very active duty.  


Jon
Newsgroups: rec.audio
From: smith@eecg.toronto.edu (Michael B. Smith)
Subject: Bi-Amp vs. Bridged Bi-Wire
Organization: Dept. of Electrical Engineering, University of Toronto
Date: 2 Sep 92 01:23:21 GMT

Assume that you have speakers that can be bi-amped and you happen to
have four amps available.  One possible setup would be to bi-amp the
speakers (i.e. one amp for the left tweeter, one amp for the left
woofer, etc.).  Assuming that your amps can be bridged, it should also
be easy to hook these speakers to be only bi-wired, but driven by
a bridged amp.  This should provide about double to triple the power,
so they'll probably be louder.  But, the big question is, which version
should sound "better"?  What are the merits of bi-wiring?

(This comes from planning a pro-logic system with 10 amps and 5
speakers, and wondering what to do with all of the extra amps...)

Michael
-- 
--
Michael B. Smith					UofT:(416)978-1652
smith@picton.eecg.toronto.edu				Electrical Engineering
--
Time is a great teacher, but unfortunately it kills all its pupils.
Newsgroups: rec.audio
From: shashaan@bronze.ucs.indiana.edu (Ali Shashaani)
Subject: Beyer Headphone Dealer?
Organization: Indiana University
Date: Fri, 28 Aug 1992 14:00:30 GMT


	Hello everyone,

	I'm interested in purchasing a set of Beyer headphones, but 
that's sort of where my knowledge ends.  What are the models that you
would recommend for home listening (in this case with a Rotel 960 preamp)?
Do you know of any reliable dealers?  Any and all replies are appreciated.
Thank you!

	--Ali
From: pardo@cs.washington.edu (David Keppel)
Newsgroups: rec.audio
Subject: CD deterioration
Date: 2 Sep 92 15:36:52 GMT
Organization: Computer Science & Engineering, U. of Washington, Seattle

[Pardon if this is a FAQ; I looked and didn't see a FAQ list.]

I have some CD's that are deteriorating, and I wonder what I can expect
for the rest of my collection.

I generally write my name in indellible marker on disks, jewel boxes,
etc., so I can loan them out and think I have a better chance of
getting them back.  I loaned a disk (Epic label, 1987 copyright) to a
friend who had skipping problems.  I held the CD up to a lamp and
looked at the other side.  Normally, litte light gets through a disk,
but where my name is written it seems that the metal in the middle of
the sandwich had disappeared along one edge of my writing, and the
light shines through brightly.

Curious, I looked at a number of other CDs in my collection.  All of
them have occasional bright spots, possibly manufacturing imperfections
and easily handled by the error correction equipment.  One of the disks
(Kaleidoscope label, 1987 copyright) has too many imperfections to
count, probably on the order of a thousand.  None of the imperfections
correspond to writing on the non-playing side, but this disk has
substantially more writing on it than the rest, as all four artists
signed the disk for me.

I've heard that the Aluminum on older disks could deteriorate, but I
was under the impression that that happened only on some older disks,
manufactured pre-1985.  I wonder if there are other sorts of expectable
deterioration, and what I can expect.  Also, I note a direct
correlation between my writing and the disk's deterioration, in the
case of the Epic-label disk, so I'm wondering if anybody knows what
about my writing on this disk caused deterioration and why it's not
apparant on the other disks I looked at.  It's a shame if my writing on
the disks -- so that I can keep my collection -- results in me losing
my collection, but I'm most concerned about avoiding future damage.

		;-D on  ( Lossy storage )  Pardo
Newsgroups: rec.audio
From: wampler@microunity.com (Kurt Wampler)
Subject: Re: How do I use a "bias fine adjustment?"
Keywords: cassette decks, gizmos, misplaced instructions.
Organization: MicroUnity Systems Engineering Inc.
Date: Fri, 28 Aug 1992 16:27:40 GMT

mather@sees.bangor.ac.uk (Paul Mather) writes:

>Finally, could someone suggest how I might use my fine bias control
>to "tune in" a tape in practise?  I recently used a That's EM-X tape
>which came out sounding a little bassy when recording with Dolby on.
--------------------------------------------------------------------------------
Here's a simple method for establishing fine bias setting without special noise
generators or other instruments:

Pick a good-quality recording; put it in your CD player.  Set up to record the
piece on the tape you want to establish a bias setting for.  Turn the fine bias
knob all the way clockwise.  Begin recording the sample selection.  With the
second-hand on your watch, adjust the fine bias control 1 step-mark every 15
seconds or so in the counter-clockwise direction until you reach the other
end of its travel.

Now rewind the tape and the CD and play them back simultaneously so you can
A/B switch between them with your tape monitor button.  Set the bias control
back to the original full-clockwise position, and follow the adjustment
procedure again, one step every 15 seconds while listening to the playback.
When the tape recording sounds closest to the original CD recording in its
treble balance, stop adjusting the bias control and note its position.  This
is close to the ideal setting for this type of tape.

You need to repeat this procedure for each brand and type of tape you intend
to record on.  I keep a little card with bias setting information under my
cassette deck for quick reference.

Kurt Wampler
wampler@MicroUnity.com
Newsgroups: rec.audio
From: gary@st.unocal.com (Gary Cattelino)
Subject: Re: A/V Prologic Receivers--FULL SUMMARY! [LON]
Organization: Unocal Corporation
Date: Wed, 2 Sep 1992 20:26:30 GMT

In article <28259@sophia.inria.fr>, td@babar.inria.fr (Thierry Despeyroux) writes:
|> I have also been impressed by the Yamaha DSP-A1000. But after this test
|> I came to a place where it was possible to compare it with other "simple"
|> amp. A good amp is by far better. In particular for classical music. So 
|> I bought a normal good amp, and I am now looking for a Dolby surround/Pro-
|> Logic/DSP for the additional channels. Of course I will have two boxes and
|> some more cables. But I hope that for the same amount of money, I will get
|> something of better musical quality.
|> 
|> When you want to buy a surround/DSP system, compare it also with traditional
|> amps. In particular if it is expensive.
|> 
|> By the way, I have read that a Kenwood (can't remember the number, but may check)
|> provides the best front amp. I don't know if you can trust in comparative tests.

Good point!  Have you listened to the hi-end Denon A/V surround amps?
The Denon A/V amps (I have a 3020) are the best I've heard.  I also
listen to a lot of classical music.

Has anyone done a serious musical evaulation of all these A/V amps?
-- 
Gary A. Cattelino                  Unocal Corporate Information Services
Phone: (714) 693-6762              5460 E. La Palma Ave.
INTERNET: gary@unocal.COM          Anaheim, CA 92807
Newsgroups: rec.audio
From: ec49726@uxa.cso.uiuc.edu (Manny C. )
Subject: Re: HSU Research Sub woofers
Organization: University of Illinois at Urbana
Date: Fri, 28 Aug 1992 07:15:46 GMT
Keywords: woofers

shiv@bnr.ca (Shiv Naimpally) writes:

>Check the Velodyne powered subs, I've heard them and they are very good.

I have the Velodyne 810. It is the lowest model that Velodyne makes and 
it is excellent for what it offers. I've tried the Yamaha, klipsch and a
couple of other homemade subs. To sum it up, Velodyne had the cleanest, 
and most powerful bass for what it has to offer. I spent the extra $100
from the Yamaha sw100 just to get the V810. It was the only sub that could
blend in with my speakers without excessive boominessnd distortion. 
The Velodynes could also play any kind of music without overkilling the bass
in some frequencies as with some other subs which are good for hitting just that one good note in a rap song.

Manny

-- 
Manny Chen                                   |      Summer of '92!
NREMT-A, CPR - Instructor  American Red Cross|
University Of Illinois @ Urbana - Champaign  |      ec49726@uxa.cso.uiuc.edu
Illini Emergency Medical Services            |
From: shiv@bnr.ca (Shiv Naimpally)
Newsgroups: rec.audio
Subject: Re: Need some DAT Advice
Date: 2 Sep 92 17:08:28 GMT
Reply-To: shiv@bnr.ca (Shiv Naimpally)
Organization: Bell-Northern Research Ltd.

You might want to try the dat-heads ! There is a dat digest that has
an excellent FAQ of prices, comments, etc. on various DATs. You can also
ask the dat-heads about various models. ANYONE interested in DAT should
subscribe:

Internet: dat-heads-request@fuggles.acc.virginia.edu
          dat-heads-request@uvaarpa.Virginia.EDU
Bitnet:   dath-req@virginia
UUCP:     ...!uunet!virginia!dat-heads-request
Newsgroups: rec.audio
From: hlj@hal.nta.no (Harald Ljoen FBA)
Subject: Re: Where can I find the Nyquest theorem
Reply-To: hlj@hal.nta.no
Organization: Norwegian Telecom Research
Date: Mon, 31 Aug 92 15:19:14 GMT

In article <1992Aug31.114555.17504@discus.technion.ac.il>, sorin@techunix.technion.ac.il (Goldenberg Sorin) writes:
>Question
>A signal say x(t) is bandlimited to W hz.
>I produce a signal x'(t) by multiplying the original signal x(t) by 0 at
>times i/2/W. x'(t)'s spectrum is the same as x(t) s. Then I sample x'(t)
              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>at time i/W/2, so I get a sampling frequency of 2W. All the samples will be
>0, so I can't construct x'(t) from it's samples. What went wrong ?
>
The assumption underlined above does not hold. x'(t)'s spectrum is not
bandlimited at all, and cannot be sampled at *any* frequency without introducing
severe aliasing errors.

-- 
***** hlj@hal.nta.no (Harald Ljo"en) expressing his private opinions ******
From: mohan@cs.utexas.edu (Mohankumar Guruswamy)
Newsgroups: rec.audio
Subject: Help with stereo pickup in a VHS VCR
Date: 2 Sep 1992 15:53:21 -0500
Organization: U Texas Dept of Computer Sciences, Austin TX
Distribution: world
NNTP-Posting-Host: cs.utexas.edu



My VHS stereo VCR (JVC HR840U) is having problems picking up the stereo
part of the audio from tapes.  I have had the VCR for about 2 years without
any problem.  I don't enjoy the movies as much as I used to when I 
could listen to the wonderful hi-fi stereo recordings :-(

I have tried cleaning the heads with a MAXELL head cleaning tape 
(the kind where you add a few drops of cleaning liquid to the tape 
before recording onto it), but it didn't help a bit.

Prior to this problem I never had to adjust tracking to get a stable picture 
(it has a "digital tracking system" - whatever that means).  
But, recently I've had to perform tracking manually for a stable 
noise-free picture.

Is there anything else I could do myself (like trying some other head-
cleaning system) before taking it in to a VCR repair shop.

Thanks in advance,

  Mohan

Newsgroups: rec.audio
From: rrogers@watson.ibm.com (Ryan Rogers)
Subject: Re: SONY STRAV970 center channel Que
Date: Fri, 28 Aug 1992 20:10:22 GMT
News-Software: IBM OS/2 PM RN (NR/2) v0.1 by O. Vishnepolsky and R. Rogers
Reply-To: rrogers@watson.ibm.com (Ryan Rogers)
Disclaimer: This posting represents the poster's views, not necessarily those of IBM
Organization: IBM T.J. Watson Research Center

In  <1992Aug27.225253.5107@tandem.com>  gekko@sjere.Berkeley.EDU (Atanu Mishra) writes:
>
>  This question is directed primarily to SONY STRAV970 owners, though
> others might also have some useful suggestions!
>
>  The AV970 receiver/amp does not come with a center-channel amp,
> unlike it's sister model, the AV1070.

  First...I own the 1070 and it does have a center channel...

>  Any and all suggestions ( including prices/places etc. ) welcome.
>

   I use Infinity SM152's as my fronts, and even though I currently do
not own a center channel speaker, I do have some suggestions.  What
ever you do, buy a speaker made specifically for the center channel
(or at lease one with minimal bass).

   When looking for a center speaker (which will typically recieve
signals from a very small range of the frequencies, that of voices),
you need one which will concentrate on those frequencies.  Also,
center channel speakers (if there any good at all) will have a case
that inhibits magnetic forces from getting in or out.  This is
due to the fact that a center speaker will most likely be near a
tv, and you can't have the two components interacting with each
other.

   The power output of the 970 is enough for any such speaker.  At
school a friend of mine had a Pioneer center channel speaker (I
can't remember the model #) which cost about $80.  Even with my
Infinity's it sounded decent and added a LOT to the surround effect
w/o a LOT of dough.

   Hope some of this info helps in your hunt.  :-)


--
Sincerely,
Ryan Rogers
From: vpo@teradata.com (Vandoren Outten)
Newsgroups: rec.audio
Subject: Re: CD deterioration
Date: 2 Sep 92 20:00:35 GMT
Reply-To: vpo@tdat.teradata.com (Vandoren Outten)
Organization: Teradata Corp., El Segundo, CA

In article <1992Sep2.153652.13952@beaver.cs.washington.edu> pardo@cs.washington.edu (David Keppel) writes:
>[Pardon if this is a FAQ; I looked and didn't see a FAQ list.]
>
>I have some CD's that are deteriorating, and I wonder what I can expect
>for the rest of my collection.
>
>I generally write my name in indellible marker on disks, jewel boxes,
>etc., so I can loan them out and think I have a better chance of
>getting them back.  I loaned a disk (Epic label, 1987 copyright) to a
>friend who had skipping problems.  I held the CD up to a lamp and
>looked at the other side.  Normally, litte light gets through a disk,
>but where my name is written it seems that the metal in the middle of
>the sandwich had disappeared along one edge of my writing, and the
>light shines through brightly.
>

Most of the stereo mags I've read have discouraged readers from
using markers to label their CDs. The fact that the damage appears where
you've written your name is the obvious clue to what the problem is.

I started buying CDs in 1984 and to date, none of them have spontaneously
deteriorated (at least I haven't noticed it).

I hope your collection is small...



               *******************************************
               * Vandoren P. Outten,  Principal Engineer *
               *  NS DBS Department,  AT&T/NCR/Teradata  *
               *   Vandoren.Outten@ElSegundoCA.NCR.COM   *
               *******************************************
               * These  opinions,  while  correct,  are  *
               * not  necessarily those  of my employer. *
               *******************************************
Newsgroups: rec.audio
From: vcb@irk.ugcs.caltech.edu (Vance Carl Bjorn)
Subject: Re: Shoppers Advantage on CompuServe
Organization: California Institute of Technology, Pasadena
Date: Thu, 3 Sep 1992 18:41:53 GMT


I purchased the Onkyo 909PRO from Shoppers Advantage for $1190 with
shipping.  This is about $200 less than the cheapest mailorder place 
and it is factory authorized, as far as I can tell.  I also purchased 
a Sharp LCD video projector a while back from them and saved $1000 over
mail order prices.  The only drawback is that it takes 3-4 weeks for
delivery.  

vcb@ugcs.caltech.edu

Newsgroups: rec.audio