HDTenEightyP/NetNews huggingface dataset:
From: DPierce@world.std.com (Richard d Pierce)
Newsgroups: rec.audio
Subject: Re: Speaker building question
Keywords: speaker building
Date: 16 Oct 92 02:07:40 GMT
Organization: The World Public Access UNIX, Brookline, MA

In article <1992Oct15.141232.4843@panix.com> moskowit@panix.com (Len Moskowitz) writes:
>
>You can make the box act as if it's bigger by stuffing it with pillow
>stuffing (polyester batting) or fiberglass insulation.  (Some folks
>use wool batting but it settles and moths find it tasty.)  Stuffed at
>1 pound-per-cubic-foot, you can get as much as a 20% apparent increase
>in volume.  There's some exotic (and not very stable) stuff that'll
>give you more than 20% but it's expensive and doesn't live very long.
>

Well you sort of can but not exactly. Adding stuffing changes the way the box
works, especially for sealed boxes, by changing the compression from
adibiatic to isothermal in nature. Theoretically, you could gain nearly a
40% advantage. But it only works for enclosure designs that can tolerate
large absorbtion losses. This is OK (and even somewhat desirable) for
sealed boxes, but can completely screw up a well tuned reflex system
unless you take it into account ahead of time.

Even still, 20% ain't a lot. For example, if the system tuning ratio is
about 2 (the box compliance is half that of the driver compliance) the
additional compliance caused by stuffing will, at best, lower the
resonance by a paltry 5%, since the driver compliance still has a
significant effect on the system compliance as a whole.

Basically, if you screwed up on your cabinet and it's too small, make a
planter or a breadbox out of it, and do it right the next time.


-- 
|                Dick Pierce                |
|    Loudspeaker and Software Consulting    |
| 17 Sartelle Street   Pepperell, MA  01463 |
|       (508) 433-9183 (Voice and FAX)      |
Newsgroups: rec.audio,rec.video,misc.consumers
From: forman@ide.com (Bonnie Forman)
Subject: Re: Problems dealing with this mail order outfit
Keywords: Electronic Wholesalers, Mitsubishi U57 VCR 
Organization: Interactive Development Environments, SF
Distribution: usa
Date: Wed, 7 Oct 92 14:45:19 GMT

>
>In fact, has anyone ever got a dealer to honor one? What
>were your experiences? Was it worth buying?
>I can "trust" Consumer Reports without having
>to believe they know everything.
>-- 
>Chris Pelkie
>Scientific Visualization Producer
>Cornell Theory Center
>Ithaca, NY 14853-3801
>chrisp@tc.cornell.edu


  OK.  Last year I had to buy some electronic equipment
   for my part time business  (I teach aerobics and needed
   to put together a relatively inexpensive, but decent
   sound system).

   One of the items I bought was a Sony walkman for $99.
   Because I was using it for my business, I didn't want
   to risk it failing on me, even though it was not that
   expensive.  I got the extended warranty (maybe $12 for
   two years).  Oh yeah, this was from the Good Guys.

   Sure enough, 10 months later, I started having a serious
   problem with one of the connections (cackling noise).
   I brought it back.  They listened to the noise, and
   gave me another one with no other questions asked.
   
   There you go.

			Bonnie
	

-- 
********************************************************************
 forman@ide.com   * ``Things that are Real are given and received  *
 !sun!ide!forman  *            in Silence''      M.B.              *
********************************************************************
Newsgroups: rec.audio
From: nau@ssesco.com (William Nau)
Subject: Re: extended warranties & bankruptcies
Organization: SSESCO
Date: Thu, 15 Oct 1992 17:24:35 GMT

>It is very likey you are speaking of the Highland Superstores which
>pulled out of Texas and many other states.  I believe they are still
>in business in other parts of the U. S.  They have an 800 number you
>can call to arrange service.  (no, I dont know it)

I'm not sure how they did it on all states, but I in Minnesota they
(Highland) contracted out to Alex Audio & Video Repair to honor all
of Highland's extended warranties.  They probably did something like
that in Texas as well.  However, if you are in MN, you now know where
to go.
Newsgroups: rec.audio
From: bill@bilver.uucp (Bill Vermillion)
Subject: Re:  Dolby C vs. dbx - correction
Organization: W. J. Vermillion - Winter Park, FL
Date: Tue, 13 Oct 1992 13:22:53 GMT

In article <1992Oct9.133947.723@cmkrnl.com> jeh@cmkrnl.com writes:

>In article <1992Oct6.163540.15201@oakhill.sps.mot.com>, rvkl60@aus18a25.sps.mot.com (Tom Mathes) writes:

>> Sorry about the screw-up part folks.

>The source of confusion here may be that "compression" can mean either boosting
>the signal or cutting it, or some of each, depending on the original signal
>level and on compressor's parameters!  

Jamie - in most audio circles compression means to limit the dynamic
range - make it smaller than the original.  The reverse is usually
called expanison.

Devices which do both are often called 'companders'.

-- 
Bill Vermillion - bill@bilver.oau.org  bill.vermillion@oau.org
                - bill@bilver.uucp 
                - ..!{peora|ge-dab|tous|tarpit}!bilver!bill

Newsgroups: rec.audio
From: deanaj@elec.canterbury.ac.nz (A. J. Dean)
Subject: Audio test CD, how much?
Organization: Electrical Engineering, University of Canterbury, New Zealand
X-Newsreader: TIN [version 1.1 PL6]
Date: Fri, 16 Oct 1992 22:21:51 GMT

I would like an audio test CD, as in one with sine waves, frequency sweeps,
low level signals, linear ramps, errors, EFM violations, close tracks, etc
etc on it. I've got some good quality music discs which I use for testing
but they can be inconvenient and they don't do things like frequency sweeps.
Basically I want a 16 bit digital audio signal generator on a disc. 

I know such things exist, and I also know they can be very expensive (like a
floppy drive alignment disc). New release CDs sell here for around $35
(US$17 I suppose) - I would pay more than that for a test disc but not that
much more (ie US$50 is getting a bit too much). Second hand wouldn't bother
me, but I suppose it would be the kind of thing you'd want to hang on to
forever.  

Thanks,
Antony (deanaj@elec.canterbury.ac.nz)
From: mbk@poincare.ucsd.edu (Matt Kennel)
Newsgroups: rec.audio
Subject: Re: optical vs. coax digital interconnects
Date: 15 Oct 1992 07:44:44 GMT
Organization: Institute For Nonlinear Science, UCSD
NNTP-Posting-Host: poincare.ucsd.edu
X-Newsreader: Tin 1.1 PL3

smee@bristol.ac.uk (Paul Smee) writes:
: With CD-ROM, the
: precise timing of the bits coming into the io register to the computer
: is not critical, as long as the line is in the proper (0 or 1) state
: when the CPU clock pulse hits.  The precise timing is handled by the
: computer, not by the CD-ROM drive.  With audio CD, it is important that
: the bit transitions occur at precisely the right time, because the
: clocking is under control of the CD 'drive'. 

Is this really true?  I have no engineering facts, but my intuition
would be that it would be standard practice for the output DAC to emit
clock samples using a newly-generated clean clock signal, and only
get the magnitude from the input data.  Considering the transformations
that it takes to get raw bits read off a CD down to the actual quantized
amplitude data, this must be what happens at some level.

: -- 
: Paul Smee, Computing Service, University of Bristol, Bristol BS8 1UD, UK
:  P.Smee@bristol.ac.uk - ..!uunet!uknet!bsmail!p.smee - Tel +44 272 303132

--
-Matt Kennel  		mbk@inls1.ucsd.edu
-Institute for Nonlinear Science, University of California, San Diego
-*** AD: Archive for nonlinear dynamics papers & programs: FTP to
-***     lyapunov.ucsd.edu, username "anonymous".
Newsgroups: rec.audio
From: geno@uhunix.uhcc.Hawaii.Edu (Geno J. Baruffi III)
Subject: Nakamichi's new AV receiver & questions
Organization: University of Hawaii at Manoa
Distribution: usa
Date: Mon, 12 Oct 1992 17:54:09 GMT


Hello,
   Hope all of you are having a good day.  I've got a quick question for
you.  Recently in the mail I received an advertisement from a local
high end shop that mentioned a dolby pro-logic receiver from Nakamichi.

Has anyone heard any information about this?  (I'm aware of the existence,
and the price, which was about $1150).

My question is, has anyone had a chance to listen to this, or seen any
reviews, or know how it compares to Denon's top AV receiver.
Or if there will be a mail order company selling it.

Also an unrelated question, I'm relatively new to the audio/video scene,
I wonder if someone could point me to a good book, that would provide
answers to common questions. Such topics might include (bridging amps,
Effects of wattage on sound, etc)


Thanks
Geno

Newsgroups: rec.audio
From: bmaraldo@watserv1.uwaterloo.ca (Commander Brett Maraldo)
Subject: Re: Black rubber CD rings - Any good ?
Organization: Unit 36 Research
Date: Wed, 14 Oct 1992 03:14:25 GMT

In article <1992Oct12.142940.18166@tc.fluke.COM> strong@tc.fluke.COM (Norm Strong) writes:
>In article <1992Oct7.090051.15754@news.weeg.uiowa.edu> smills@news.weeg.uiowa.edu (MuffinHead) writes:
>}gre253@mis.csiro.au (Steven Green (+61 6 276 6813)) writes:
>}>I have often seen adds for these black rubber CD rings in hi-fi magazines and
>}>thought nothing of them. Yesterday I borrowed an "Audio test" CD from a freind.
>}   The only thing they DO do is keep the edges from chipping if you happen
>}to drop the CD on concrete. They do NOTHING for the sound. It's another
>}Green Magic Marker phenomenon.
>As a matter of fact, they may actually ruin the sound.  The mass of the
>CD is part of a servo loop that controls the speed of the disc.  This is
>a negative feedback loop.  Adding mass to the CD just may cause this
>loop to become unstable.  It probably won't, because there is
>undoubtedly a large phase margin in the loop.  But it might! 

	From my experience the rings do not add enough weight to the disc to
cause tracking or speed feedback problems.  When I use the rings at home I
do not notice a change in sonic quality.  I do notice that the CD lens tracks
much better.  My evidence of this is by directly observing the lens focus
as the disc spins.  The lens moves in and out much less with a ring in place
on the same CD.  When I use the refracting light absorber, the allsop ring
and Finyl together I do notice a significant improvement in the sound.  I may
be convincing myelf of this, but to my ears its there.  On my friends higher
end system (Escoteric Audio, Krell, Martin Logan) I notice an improvement
with each of the three methods used individually.

Brett Maraldo


-- 
               --------     Unit 36 Research     ---------
	                "Alien Technology Today"
  	 	      bmaraldo@watserv1.UWaterloo.ca
  	           {uunet!clyde!utai}!watserv1!bmaraldo
From: kmr4@po.CWRU.Edu (Keith M. Ryan)
Newsgroups: rec.audio
Subject: Re: Stereo Review (was Re: Very expensive cables)
Date: 9 Oct 1992 16:10:15 GMT
Organization: Case Western Reserve University, Cleveland, OH (USA)
Reply-To: kmr4@po.CWRU.Edu (Keith M. Ryan)
NNTP-Posting-Host: thor.ins.cwru.edu


In a previous article, kester@mte.ncsu.edu (Dan Kester) says:


>I've seen very few (none?) posts from people who have heard differences between
>cables trying to explain those differences.  I have seen MANY posts from people
>who have all sorts of explanations why I shouldn't be able to hear the
>differences I claim to hear.  Who then leap to the conclusion that I didn't
>really hear them at all!
>
>I also see many posts saying that anyone who buys cable other than what can be
>found in a hardware store is a complete idiot.  I have asked before, and ask
>again:  Have these people even bothered to try to hear for themselves if
>different cables sound different????  If, after doing serious auditioning, they
>fail to hear differences, fine.  But don't go around spouting conclusions about
>what can or cannot be heard, that are not based on anything other than first
>semester EE courses!

	I agree. I have heard differences between certain cables, albeit
I feel certain individuals overexagerate the benafits. However, I am not
trying to come up with any cockamamie theories on cable design.

	This is the main problem I have with the ads. I can accept them
saying it sounds different. ( after all, so do I ) But, I can not handle
their BS on why it sounds different. To give you an example: 

	Most Audioquest ads are reasonable. They tell you their construction
	physically,not some mumbo jumbo. "Emerald uses 99.99..% percent pure	
	copper, Lapis and Diamond use pure solid silver. All three are resis-
	tance welded to direct-gold plated FPC copper plugs ( RCA or XLR )."
	
	Then there are the ones which just ooze BS and snake oil: such as
	Tice. Come one, trained electrons? He speaks as if they went to	obe-
	dience school! If you claim your products sound different, fine. I
	can handle that, but don't try to justify your claims with BS!

	Another problem is overexageration. Sure, I understand some of it
	is PR marketing, but come on! [ maybe I'm hypocritical on this, as
	I love the Maxell ads... ]


	Because I feel this way, I auditioned cables which I felt were made
by more honest and reputable people. That's why I settled on the Audioquests.
( I did in home tests on 5 RCA cables, and 3 speaker wires ). And, they did
not cost me an arm and a leg! [ sure, the silver lapis sure sounded better,
but just was not worth the increased cost, IMHO ]

-- 
	Mr. Bush has the dubious distinction of the second largest tax
raise in US history; right behind Mr. Reagan. They're the real slickersters,
with their theivery fingers in our wallets, with a grin and a gleem in their 
eyes.   What a "no new taxes" bastard.
Newsgroups: rec.audio
From: alex@research.canon.oz.au (Alex Danilo)
Subject: Re: pro logic
Summary: Everyone should have it
Keywords: how does this work
Organization: Canon Information Systems Research Australia
Date: Wed, 14 Oct 1992 10:03:26 GMT

In article <183804@pyramid.pyramid.com>,
 lstowell@pyrnova.pyramid.com (Lon Stowell) Writes:

> In article <3901@faatcrl.faa.gov> frankc@faatcrl (Frank Coffman) writes:
> >...what it does, but I don't understand HOW it does it, and the salespeople
> >I've talked to obviously don't know themselves.
> >
> >Does it just work on recorded media?   
>     No.  Whether it works at all on recorded media depends on
>     whether or not the recording has Dolby Surround encoding.
> >Does it do it's thing on regular TV broadcasts?
>     If they are Dolby Surround encoded, yes.

It works by phase encoding the background channel information onto a stereo
pair. The stereo signals typically have to be amplitude correlated within
about 1/2 db, this is done by the decoder. It basically 'grabs' the common
signal (bandwidth limited) and sends it to the centre speaker, then subtracts
this signal from the left/right pair. The rear signal is then delayed, 7.5kHz
limited and sent to the back pair. The surround pair really contain a mono
signal, as you'd find in a cinema, though a lot of commercial units will add
a bit of left/right to give a sort of stereo effect from the rear.

> >Is this a flash in the pan?
> >
>     Isn't everything?

Hardly, almost all of the movies coming out for years have been dolby encoded,
the only recent (serious) alternative has been the LucasFilm THX system.

> >Is it time to buy or is the technology still unfolding?
> 
>    There's lotsa programming out there that is Dolby Surround
>    encoded.   
> 
>    Pro-Logic is just an enhancement to the decoder....
> 
Pro Logic means 5 speakers, normal cheap Dolby surround units have only 4,
i.e. no centre speaker. Pro-Logic is the only real one (ala cinemas), the
reason for the centre speaker is so that no matter where you are in the room,
the dialog comes from the middle - no stereo imaging required. Since the main
thrust of cinema surround comes from systems using a centre speaker, nothing
else will do - i.e. don't just buy Dolby Surround, buy Pro-Logic.
	Having used it for years now, combined with a video projector, it
gives a great effect - not as subjectively spectacular as some hall-effect
stereo, but excellent for properly mixed Dolby films (read, more realistic).
From: rghoff@bb1t.monsanto.com
Newsgroups: rec.audio
Subject: Elect. Ground = Expensive cables?
Date: 9 Oct 92 16:08:53 CST
Organization: Monsanto Company, St. Louis, MO



	I thought I add another dimension to the "Green Pen" list. And
	this is one that I think really does help the system's performance.

	Use a copper grounding spike for you house wiring instead of 
	hooking up the the cold water pipes. The idea being that you will
	isolate your wiring from the rest of the neighborhood - or 
	something like that.
	
	I did this about a year ago and it seems that my TV has a cleaner
	picture and maybe, just maybe, my stereo sounds a little cleaner.
	The TV picture is a definate, the stereo is a big maybe (just trying
	to justify the extra $25.00 for the spike to my wife probably :-).

	What do the rest of you on this group think?

	Oh, BTW, I do use the water pipes for my TV and scanner antenna's.
	Shouldn't that counteract any affects of the grounding spike?

	From one that doesn't beleive in the magic of monster cables.....

	Rick Hoffman.




Newsgroups: rec.audio
From: resou@darcy.mi.uib.no (Odd Arild Urtveit)
Subject: Re: Black rubber CD rings - Any good ?
Organization: University of Bergen, Norway
Date: Wed, 7 Oct 92 12:25:42 GMT

In article <1992Oct7.090051.15754@news.weeg.uiowa.edu>, smills@news.weeg.uiowa.edu (MuffinHead) writes:
> gre253@mis.csiro.au (Steven Green (+61 6 276 6813)) writes:
> 
> >I have often seen adds for these black rubber CD rings in hi-fi magazines and
> >thought nothing of them. Yesterday I borrowed an "Audio test" CD from a freind.
> >It had one of these on it. The music tracks on this CD sound great. I tried
> >it without the ring and could not detect any difference.
> >Whats the feeling of people out there regarding these rings. Are they simply
> >another snake-oil remedy or do they actually work ?
> 
>    The only thing they DO do is keep the edges from chipping if you happen
> to drop the CD on concrete. They do NOTHING for the sound. It's another
> Green Magic Marker phenomenon.
> 

Hi MuffinHead!

I've been experimenting with what you call 'Green Magic Markers' for a while and have diskovered that they makes big improvement to SOME CDs, not all.  In the beginning I thought, like you, that this would not work, and on the first CD it didn't.  The truth is that the effect of theese (well, I've actually just tried one, the 'CD Stoplight') green pens are very much dependent on the CD.  On some CDs the effect is neglible but on others it may open a new world to you.  The effect may also vary from on CD pl




ayer to another.  And one improtant thing:  If you use a realy good pair of headphones, like the Stax Lambda (the one I'm using), you should be able to hear differences on almost all CDs.  I once turned a disbeliever into a believer in a snap by 'painting' one of his bad sounding CD with the Stoplight.  He spent the rest of the night listening to the CD.

One CD I've discovered big improvement on is Paul Simon's 'The Rythm Of The Saints'.  On one of the tracks there are lots of 'jungle noises'.  Without the green marker it feels like you are standing in the beginning of the forrest, but with the marker you are standing in the middle of it with the sound comming from all directions.

Odd Arild Urtveit.
resou@mi.uib.no
From: znpt01@trc.amoco.com (Norman P. Tracy)
Newsgroups: rec.audio
Subject: Re: magazines
Date: 7 Oct 92 21:41:20 GMT
Organization: Amoco Production Company, Tulsa Research
Originator: znpt01@gpss43


In article <440@bit.UUCP>, grego@bit.UUCP (Greg Sanguinetti) writes:
> In article <1992Oct1.224748.13054@newshost.unh.edu> dcm2@kepler.unh.edu (Tommy the Cat) writes:
> > requested magazine recomendations for working with tube audio projects:
> 
> Chris, try out Glass Audio. It only comes out twice a year and costs $18
> for a two year sub but is reported to be well worth it if you are serious
> about heating glass. Give em a call at (603)924-9464
> 
> Now me, I'm hopelessly stuck on silicon substrates so this recomendation
> is second hand.
> -grego
> -- 

Slight correction, Glass Audio is now published 4 times a year.  The full
address is:

Audio Amateur Publications
POBox 576, Dept E92, Peterborough, NH 03458
(603) 924-9464 voice (603) 924-9467 fax

Back issues are available, the '92 series has really come into its own.

Call for a free catalog sez happy customer:
Norman Tracy (znpt01@trc.amoco.com)
Newsgroups: rec.audio
From: trussell@cwis.unomaha.edu (Tim Russell)
Subject: Re: Terk Powered FM Antennas
Organization: University of Nebraska at Omaha
Date: Fri, 16 Oct 1992 23:39:41 GMT

gerald.b.ross@um.cc.umich.edu (Gerald Ross) writes:

>Any comments of these Terk powered antennas?

    I don't use one at home because I don't need it, but I have one on my
stereo in my office at work, since it's inside a metal building with opaque
windows, etc.  It helps me pull in area stations quite nicely, and doesn't
amplify the noise of my computer sitting next to it much either.  I'm quite
happy with it.

    Not sure what model it is, but it's the vertical one with the blue loop
that folds down and the dial on the right side.  I got it for about $35
at a local audio store.

--
   Tim Russell                 Omaha, NE              trussell@unomaha.edu
      "Who can doubt that pleasure is the only goal of a reasoned life?"
                                                   -- Epicurus
Newsgroups: rec.audio
From: greene@newton.ccs.tuns.ca (Courtney Greene)
Subject: Driver quality & ports
Organization: Technical University of Nova Scotia, Halifax, N.S.
Date: Tue, 13 Oct 1992 15:06:02 GMT

Hello,

I'm about to order some drivers to build a set of speakers. I've
narrowed my choices (due to $) down to seas, vifa or peerlerss. I don't
have my catalogue with me so I can't quote model numbers, but can anyone
compare the overall quality of drivers from the three mentioned companies.

I intend to build the speakers from a kit, the kit consists of a diagram
and the necessary components (not the box). If I choose to double the 
thickness of the front board on which I wish to mount the drivers do I
need to lengthen the port tube? In other words is the length of the tube
based on a cabinet thickness of 19mm or .75in? or is it simply the length
of tube through which the sound must travel?

Thanks,
Courtney
greene@tuns.ca

Newsgroups: rec.audio
From: kester@mte.ncsu.edu (Dan Kester)
Subject: Re: Stereo Review (was Re: Very expensive cables)
Organization: North Carolina State University
Date: Fri, 9 Oct 1992 14:27:50 GMT

In article <7490238@hpfcso.FC.HP.COM> myers@hpfcso.FC.HP.COM (Bob Myers)
writes:

>
>Now, note that the above doesn't say that a given individual shouldn't
>do whatever the hell they want to with their own hard-earned bucks.  I
>would be the last person to try to talk you out of your choice if you've
>listened and truly believe that you hear a difference - it's not MY money,
>and it's therefore none of MY business.  Just don't then start posting about
>WHY the damn things work unless you've got some better ideas than we've seen
>presented in the past, and don't expect everyone to automatically accept
>the idea that the difference is real and repeatable.
>

I've seen very few (none?) posts from people who have heard differences between
cables trying to explain those differences.  I have seen MANY posts from people
who have all sorts of explanations why I shouldn't be able to hear the
differences I claim to hear.  Who then leap to the conclusion that I didn't
really hear them at all!

I also see many posts saying that anyone who buys cable other than what can be
found in a hardware store is a complete idiot.  I have asked before, and ask
again:  Have these people even bothered to try to hear for themselves if
different cables sound different????  If, after doing serious auditioning, they
fail to hear differences, fine.  But don't go around spouting conclusions about
what can or cannot be heard, that are not based on anything other than first
semester EE courses!

Dan Kester
kester@mte.ncsu.edu