HDTenEightyP/NetNews huggingface dataset:
From: matthews@eecs.ucdavis.edu (Thomas W. Matthews)
Newsgroups: rec.audio
Subject: Re: Cable Design Proposal
Date: 17 Nov 92 17:36:54 GMT
Organization: Division of Electrical Engineering and Computer Science, UC Davis


 kirk@hpcc01.corp.hp.com (Kirk Lindstrom) has written:

>WHAT IF.....I took a cable that was 50 Ohms at one end and tapered it to
>say 300 Ohms at the other end say 1 meter away.  I then put gold plated,
>RCA connectors on it and tell the user to plug the 50 Ohm end into their
>preamp and to plug the 300 Ohm end into their amp making sure not to mix
>this up.

I think that the transmission line must be at least a certain length,
expressed in wavelengths of the signal in the transmission line, before
the transformation of impedance will be effective.  In other words, the 
wavlength of even the highest frequency audio signal will still be so long
in the transmission line that what we see as a gradual taper will, to the 
waveform, be just another impedance bump  

>this up.  Me thinks that the preamp will deliver just a we bit more
>voltage to the amp with this strange cable and any reflections will be
>absorbed due to the low impedance upon return.

If the 50-Ohm end of the cable is driven with a 50-Ohm source, then 
reflections will be minimized at that termination (to the extent that 
the tapered cable really does have a 50-Ohm impedance there.

Certainly, according to traditional thinking, reflections on audio
"interconnects" of reasonable length are too quick to affect even a
20 kHz. component.   I'll take a guess at how one might calculate
the bad effects of reflections, and then someone else who has
given more thought to this area can give us a better idea.

If the interconnect is one meter long and has a propagation
velocity (is that the right term?) one-quarter the speed of
light, ten round-trip bounces (20 meters distance) would take 
267 nanoseconds.  One cycle at 50 kHz. takes 20 microseconds.
I think that after twenty bounces, any reflection would have 
dropped quite a bit in amplitude, and it will make about 360
bounces before the time of one-quarter cycle at 50 kHz. has passed.

Suppose that at each reflection, 0.8 of the signal amplitude
is reflected.  Then after 360 bounces, the signal amplitude is
698 dB down.  Is anyone advocating the position that an effect 
which decays to -698 dB within one-quarter cycle of a frequency 
that is well above the range of audibility produces an audible effect?

If I were experiencing some trouble with a particular interconnect,
I would be inclined to consider other factors before suspecting
reflections as the cause.  

I thought I'd post this to show how I'd approach the question, given
my engineering training.  However, I recognize that I may have
overlooked something, or even be completely wrong.  Given that
many readers think reflections are important, and my analysis
leads me to believe that they're not, I'm interested in reading
and learning from any discussion which follows.

Tom Matthews
Newsgroups: rec.audio
From: kong@leland.Stanford.EDU (Kong Kritayakirana)
Subject: JVC Mail Order
Organization: DSG, Stanford University, CA 94305, USA
Distribution: usa
Date: Fri, 20 Nov 92 04:47:52 GMT

Does anyone know a good place to mail-order JVC stuff. I'm interested in 
getting their 1050 CD player. A local store quoted me $650 on it. After
California's brutal sales tax, the total comes out to be $703. It is still
$100 below the MSRP. Will I save much more through mail order? I hate to
wait for things to get shipped to me, especially when I order from stores
in the east.

Kong Kritayakirana		kong@leland.stanford.edu
Newsgroups: rec.audio
Subject: Re: Why filter D/A output?
From: MATGBB@LURE.LATROBE.EDU.AU (BYRNES,Graham)
Date: Fri, 20 Nov 1992 00:04:15 GMT
 <1992Nov10.051755.21660@lugb.latrobe.edu.au> <PHILG.92Nov11173959@zug.ai.mit.edu> <1992Nov12.201144.28397@en.ecn.purdue.edu>
Organization: La Trobe University
X-News-Reader: VMS NEWS 1.24

In <1992Nov12.201144.28397@en.ecn.purdue.edu> syd@en.ecn.purdue.edu writes:

> philg@martigny.ai.mit.edu writes:
> 
> >Driving a nonlinear, i.e. distorting, system, i.e. amplifier/speaker,
> >with a single frequency produces an output made up only of that
> >frequency and its harmonics.  This can be shown easily by looking at a
> >Taylor series expansion of a nonlinear function and seeing what
> >happens to cosine squared and cosine cubed terms (use trig
> >identities).
> 
> This is [mathematically] not true in general.  
> Example: f(x) = arccos (x).  The output of such a system 
> when x = cos(t) is simply t, which is not periodic, and
> hence does not have a Fourier series expansion.
> 
> One could be more obnoxious by letting f(x) = cos (1.5 arccos(x)).
> 
> The Taylor series must converge at every point in order for this
> argument to work.  (Note that arccos (x) does not meet this requirement.)
> A sufficient condition for this is that the nonlinearity be continuous.
> (In the real world, this is probably a valid assumption.)
> 
> -- 
> Dennis Hilgenberg
> syd@ecn.purdue.edu
> LaRouche in '96
I guess we can at least assume that the transfer function is bounded
over any compact interval ? :-) One might even hope that it would be 
continuous....so we can use Taylor's theorem to get an arbitrarily
accurate approximation over the domain (ie possible input values).
Cheers, GB
(Yeah, I know, what a wank)
Newsgroups: rec.audio
From: whs70@dancer.cc.bellcore.com (sohl,william h)
Subject: Re: DAT and SCMS, some info
Organization: Bellcore, Livingston, NJ
Date: Fri, 20 Nov 92 16:52:21 GMT

In article <RLK.92Nov20095023@underprize.think.com> rlk@underprize.think.com (Robert Krawitz) writes:
>In article <1992Nov19.223410.21621@porthos.cc.bellcore.com> whs70@dancer.cc.bellcore.com (sohl,william h) writes:
>
>   In article <RLK.92Nov19155321@underprize.think.com> rlk@underprize.think.com (Robert Krawitz) writes:
>   >I'm curious as to whether the HRRA forbids record companies from putting
>   >an SCMS 10 code (no digital copies) on digital media?
>
>   A recording company is under no legal obligation to code original
>   material as uncopieable or otherwise.  In other words, if someone
>   wants to sell a CD or DAT tape which doesn't prohibit multiple
>   generations of copying, then the producer/originator of that CD
>   or DAT is perfectly free to encode the SCMS with an 00 coding
>   for unlimited copying.  
>
>I understand that.  My question is whether a record company is legally
>prohibited from using the 10 code, forbidding ANY copying.

Oops, sorry I misread what you were asking.  I just browsed through my
copy of the HRRA and can't see anything that would seemingly state that
a producer of CDs, DATs, etc. can't encode with a 10 code (the codes
themselves aren't even mentioned).  If, howver, a company did that, it
still wouldn't stop the digital-analog-digital copying, AND, it would
become known pretty fast that XXX CD is encoded with a "prohibit all
digital copies" coding and might then actually result in a lower
number of sales.

As several others have mentioned, the real gain for the recording
industry is the royalty tax on blank digital tapes.  I suspect the
industry fully knows it can't stop any of the taping that generally
goes on by individuals for their own use and they won't really try
to either.  The thing to watch is the probable cry for higher
royalty taxes in the future as well as an extension of royalty taxes
on other blank media (eg. analog cassettes, computer discs, etc.)

Standard Disclaimer- Any opinions, etc. are mine and NOT my employer's.
-----------------------------------------------------------------------
Note - If email replying to me with an automatic addressing process
bounces, manually address the resend using one of the addresses below.
-----------------------------------------------------------------------
Bill Sohl (K2UNK) BELLCORE (Bell Communications Research, Inc.)
Morristown, NJ             email via UUCP      bcr!dancer!whs70
201-829-2879 Weekdays      email via Internet  whs70@dancer.cc.bellcore.com

Newsgroups: rec.audio
From: bill@bilver.uucp (Bill Vermillion)
Subject: Re: Help!
Organization: W. J. Vermillion - Winter Park, FL
Date: Mon, 23 Nov 1992 14:42:39 GMT

In article <1992Nov22.201146.4559@news.columbia.edu> gmw1@cunixa.cc.columbia.edu (Gabe M Wiener) writes:
>In article <1992Nov19.223929.19874@bilver.uucp> bill@bilver.uucp (Bill Vermillion) writes:

>>While the erstwhile Tom Edison is know for having invented the
>>phonograph, he did not invent the record.  His phonograph used
>>cylinders.

>As far as I know, Edison *did* make discs also, but the groove was vertical
>instead of horizontal.

That was after Berliner if I remember.  I'll have to check.  A
great book on the history of audio is "From Tinfoil To Stereo".
Long out of print, but your local library may have it.

>>Emile also invented that wonderful device that we all know and low so
>>well - the microphone.

>Hm?  I would think that we'd credit the first microphone with Alexander
>Graham Bell...

Picky picky picky :-)

-- 
Bill Vermillion - bill@bilver.oau.org  bill.vermillion@oau.org
                - bill@bilver.uucp 
                - ..!{peora|tous|tarpit}!bilver!bill
From: tommes@convex.rz.uni-duesseldorf.de (Peter Tommes)
Newsgroups: rec.audio
Subject: INFO wanted: Musical Fidelity CD 1
Date: 16 Nov 1992 17:00:44 +0100
Organization: Heinrich-Heine-Universitaet Duesseldorf
NNTP-Posting-Host: convex.rz.uni-duesseldorf.de


I am considering to buy a Musical Fidelity CD 1 CD player. Does anyone have
comments to this player ? Any experiences ?
Thanks
Peter
From: alves@calvin.usc.edu (William Alves)
Newsgroups: rec.audio
Subject: Re: Interface Digital Audio <---> Computer ???
Date: 23 Nov 1992 17:53:05 -0800
Organization: University of Southern California, Los Angeles, CA
NNTP-Posting-Host: calvin.usc.edu

In article <logan.722231192@nectarine> logan@nectarine.ucsb.edu (Logan O. Bruns) writes:

>Does anyone know of any software, preferably PD, that will allow you to
>read audio data off a audio CD with a CDROM drive? 

It's a question of hardware, not software. Usually the D/A converter for
audio is a completely different data stream than CD-ROM data. I think
someone mentioned that the SGI CD-ROM has the capability, in addition to
the new Apple CD-ROMs.

>Also what format is sound stored in on audio CDs?

If you mean what audio format, 44.1kHz sampling rate 16-bit samples linear
pulse-code modulation. The actual format of the information on the disc
involves error-correction redundancy, inleaving, multiplexing, and "8 to
14" modulation (to keep the pits near their optimum size). For the details
of all of this information see Ken Pohlmann's book on Digital Audio or
Compact Discs.

Bill Alves

Newsgroups: rec.audio
From: znpt01@trc.amoco.com (Norman P. Tracy)
Subject: Re: 
Originator: znpt01@gpss43
Organization: Amoco Production Company, Tulsa Research
Date: Wed, 18 Nov 1992 21:15:55 GMT


With apologies to victims of hurricane Andrew, but as a victim of Stereo
Review I can't resist.

In article ,  writes:
> In rec.audio, jj@alice.att.com (jj, curmudgeon and all-around grouch) writes:

> I just got done reading the review of the Philips DCC900 DCC deck in
> this month's Stereo Review (everyone interested in DCC and MD should
> pick up a copy of this).  The reviewer concludes: "...anyone who
> expects to find that perceptual coding is hokum, or that their ears
> transcend the physiological constraints upon which it is based, will be
> shocked by the very high-fidelity sound DCC actually delivers.  There
> is..............
> 
> In his few hours of testing (before Hurricane Andrew hit his office),
         ------------------------------------------------------------
> he basically couldn't hear a difference between the CD and the DCC
> recording of the CD.  I find it hard the believe that any recording
> system that can do this, will degrade worse than cassette on multiple
> generations.  And, I expect that it's much better ...............
> 
> Curt

I can picture this life size...........
Reviewer - "Sorry about the DCC900 review but Andrew is about to hit us,
gotta evacuate."
Editor (snug as a bug in a rug in his New York office) - "WHAT!!!! Phillips
has bought two page ads in every issue for the rest of the year. I've
GOT to have that review or your (line breaks up as tree falls on wires)."
Reviewer - "But boss .."
Editor - No buts, you've got the only DCC900 in North America an I WILL have
your review in my fax hopper or you'll never see another Pioneer A/V receiver
for as long as you live.  Fail me and you'll never work in this town again!"
Reviewer - "Yes, sir."
Hanging up his phone the dejected Reviewer returns to the equipment rack.
As the 50mph winds beat rain against his windows he loads the CD and DCC
with identical copies of 'Oliva Newtion John's Greatest Hits'.  Taking his
place in the Listening Chair he picks up the remotes to begin the critical
test upon which millions of audiophiles throughout the english speaking
world will base their judgements.

Norman Tracy (ntracy@trc.amoco.com)
From: smee@bristol.ac.uk (Paul Smee)
Newsgroups: rec.audio
Subject: Re: Pioneer LLC CD players
Date: 23 Nov 92 10:32:42 GMT
Reply-To: P.Smee@bristol.ac.uk (Paul Smee)
Organization: University of Bristol

In article <1992Nov19.204304.3607@spang.Camosun.BC.CA> dbarker@spang.Camosun.BC.CA (Deryk Barker) writes:
>Does anyone have any experience with the new Pioneer LLC (can't recall
>what it stands for) CD players? Reviews I've seen sound encouraging.
>
>Deryk Barker, Computer Science Dept., Camosun College, Victoria B.C.

Hey, hi there Deryk, fancy seeing you here.

One of our hifi mags did a short article about it last month.
Basically, the ads are mis-leading.  It does NOT 'faithfully reproduce
the freqs above 22 KHz' -- which, Nyquist would tell us, is impossible
anyway.  What it does is use a sort of weaker filtering, so that some
of the artifacts from the sampling and reconstruction process come
through.

In essence, with 44.1 kHz sampling, when you reconstruct you get the
original frequency spectrum, plus a 'reflection' off of 44.1 kHz.
(Plus higher order ones which we'll ignore.)  E.g. if the real music
contains 5kHz, 12kHz, and 20kHz signals, then with LLC the reconstructed 
stuff contains that plus 39.1kHz (44.1 - 5), 32.1kHz (44.1 - 12) and
24.1kHz (you get the idea).

There's evidence to show that some people find that this extra
high-freq stuff helps make the thing sound 'better' in some strange
way, even though it's (a) theoretically beyond the range of hearing,
and (b) not the real harmonics you'd expect with those signals.
However, some people find it sounds worse.  (And, of course, some can't
tell the difference.)

One thing the article specifically warned about, though, is that the
presence of that super-audio signal can drive some amps into heavy
intermodulation distortion -- which you might not like.  Also, some of
those 'super-audio' freqs may approach the breakup frequency of your
speakers (specially if you have metal-dome tweeters) which again can
have 'interesting' effects on the sound.  (In fact, given that you
shouldn't be able to hear these freqs, seems to me that a plausible
explanation of the alleged audio effect might be that the unhearable
stuff drives the amps and speakers into a pathological condition which
might or might not be nicer, but which is has effects down in the
hearing range.

Or, in other words, for sure you shouldn't buy one unless you've tried
it with the same amp/speakers setup you plan to listen to it with, and
have decided that you personally like it. 

-- 
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
From: hoov@hogbbs.scol.pa.us (Brian Hoover)
Newsgroups: rec.audio
Subject: Sony discmen
Date: Sun, 15 Nov 92 18:49:54 EST
Organization: The Heart of Gold BBS, Lemont PA

From what I've read, the two players basically have the same features.  
The 808k is streamlined and alot thinner than the 802k, if that is a 
factor for you.  Generally speaking, tho, these CD players are almost 
identical.  However, I have never used either of the two models, so I'm 
not absolutely sure as to the exact features of each.  Go to your local 
audio store and ask the salesperson.  They are the most qualified in 
answerin such questions.

                                     Hoov
From: gmw1@cunixa.cc.columbia.edu (Gabe M Wiener)
Newsgroups: rec.audio
Subject: Re: reel-to-reel decks ?
Date: 22 Nov 92 20:24:25 GMT
Reply-To: gmw1@cunixa.cc.columbia.edu (Gabe M Wiener)
Organization: Columbia University

In article <1992Nov21.000040.11533@cc.umontreal.ca> rodiers@JSP.UMontreal.CA (Rodier Stephane) writes:
>
>        Can anyone give me manufacturers name that makes reel-to-rell decks
>other than TEAC and REVOX (by the way do they still make them ?). 
>Furthermore, some price range would be appreciated....

Tascam (teac), Studer (revox), Otari, Sony, Fostex.


--
Gabe Wiener - Columbia Univ.     "This 'telephone' has too many shortcomings 
gmw1@cunixa.cc.columbia.edu       to be seriously considered as a means of 
N2GPZ in ham radio circles        communication. The device is inherently of
72355,1226 on CI$                 no value to us." -Western Union memo, 1877
Newsgroups: rec.audio
From: mjf9968@rigel.tamu.edu (Pi(3.143832666))
Subject: new *M*U*S*I*C* *L*I*T*E*
News-Software: VAX/VMS VNEWS 1.41    
Keywords:  ;)
Organization: Texas A&M University, Academic Computing Services
Date: Wed, 18 Nov 1992 13:15:00 GMT


                        PHILLIPS

	the company that brought you the cassette
	tape-- the only medium that *guarantees* the
	consumer will have to by a new copy of that
	favorite album every two years-- now brings
	you:

                   *M*U*S*I*C* *L*I*T*E*
                         (aka DCC)

	YES!  New and amazing Music Lite!   All the
	profit margin with only 80% of the sound!

	Why give your customers all the music at 
	half the price when you can give them half
	the music at all the price?

	Yes, with our new and wonderful compression
	scheme we can delete out those parts of the
	music that the consumer won't really miss
	anyway.  Our test show that the Average
	Consumer won't be able to tell the difference,
	as long as you show them lot's of charts
	before-hand proving that they won't be able
	to tell the difference.  That's what psycho-
	acoustics are all about!  Just let them play
	with all the nifty buttons on our machines
	and all talk of "lossy compression" goes right
	out the window!

               Remember, that's Phillips' new 

                   *M*U*S*I*C* *L*I*T*E*
            "It's digital, so it HAS to be good!!"
From: lihan@ccwf.cc.utexas.edu (Bruce G. Bostwick)
Newsgroups: rec.audio
Subject: Re: Dolby C
Keywords: Dolby
Date: 22 Nov 92 20:36:06 GMT
Distribution: usa
Organization: The University of Texas at Austin, Austin TX

ssr@cypress.com (Bapcha/FPGA) writes:
>gmw1@cunixa.cc.columbia.edu (Gabe M Wiener) writes:
>>
>>Dolby C is dynamic, Dolby B is static.  The compression effect changes
>>throughout a Dolby C recording.  As such, you *cannot* readily play it
>>back on a machine without Dolby C, whereas you certainly can play a Dolby
>>B tape back on a machine sans Dolby.
>>
>>Playing a Dolby C tape back w/o Dolby C will give, ah, less than desirable
>>results.

^^ this is very similar to my experiences with Dolby C ^^

>NOOOOOOOOOOO!!!!!!!!!!!!!!  Dolby B and C have similar ways of compensating
>for the hiss on a tape (assuming a zero noise source).  B compensates by
>10dB and C; by 20dB.  Hence if you record Dolby C,  and play it back on Dolby
>B,  just use the treble control to cut 10dB (oh well - till it sounds less
>"shrill"),  and you'll be all set !!

No, I'm afraid you're wrong.  Dolby C is definitely dynamic in its
compression -- you can hear it if you happen to play back a C-encoded
tape without any Dolby, and less pronounced if you play back with B
instead of C.  You can also hear the effect if you happen to have C
engaged on a non-C tape -- the compression and envelope change in
response to high-end peaks on the tape, which does not happen with B.
(I tend to prefer not to use C for this very reason -- it works better
if you use C on both ends, but the results are so distressing on
anything that can't decode C, like my wife's stereo and both of the
decks in our cars! -- because the drawbacks and hassles outweigh the
10-15% improvement in dynamic range.)

The companding in Dolby, incidentally, is just in the top part of the
signal spectrum, unlike dbx (rest its soul) which compresses/expands
the entire spectrum.  B and C divide the spectrum differently as well.

oh well, at least it's not Burwen system...

-- 
<BGB>
lihan@ccwf.cc.utexas.edu        /     "I can't complain,
(really Bruce Bostwick)        /   but sometimes I still do"
from the great state of TEXAS /         --Joe Walsh--
From: lstowell@pyrnova.mis.pyramid.com (Lon Stowell)
Newsgroups: rec.audio
Subject: Re: HELP! Info on MD and DCC
Date: 23 Nov 92 21:01:59 GMT
Reply-To: lstowell@pyrnova.pyramid.com (Lon Stowell)
Organization: Pyramid Technology Corp., Mountain View, CA

In article <7490254@hpfcso.FC.HP.COM> myers@hpfcso.FC.HP.COM (Bob Myers) writes:
>
>Hey, anybody remember the ORIGINAL stereo disc format, in which there were 
>two completely separate tracks, and you played the thing with a Y-shaped
>tonearm?
>
    Wasn't that the Cook format?
From: kim@Software.Mitel.COM (Kim Letkeman)
Newsgroups: rec.audio
Subject: Re: TV speakers as centre channel ( was Re: Pro Logic Center channel speakers )
Date: 16 Nov 92 14:15:24 GMT
	<lg00njINNqj8@exodus.Eng.Sun.COM>
	<1992Nov16.030619.4152@mel.dit.csiro.au>
Organization: MITEL Public Switching, Kanata, Ontario, Canada
In-reply-to: gre253@mis.csiro.au's message of 16 Nov 92 03:06:19 GMT

In article <1992Nov16.030619.4152@mel.dit.csiro.au> gre253@mis.csiro.au (Steven Green (+61 6 276 6813)) writes:

| Firstly, the speakers in you TV are shit compared to virtually any
| centre speaker you can buy. Even high-end TV's have shit speakers!

Absloutely correct. Since Dolby recommends a speaker of the same
quality as the left and right speakers, the only thing that would make
TV speakers acceptable as center channels is to use TV quality
speakers for the left and right as well. I shudder at the thought.

| However, a centre speaker tends to move the dialog off screen. Try
| closing your eyes and mentally placing where the people are - you
| see what I'm talking about.

This is useful as a mental exercise perhaps, but is not all that
relevant to real life. I use a pair of unshielded speakers as my
centers and sit them a foot above the TV. They are almost 2 feet above
the main speakers. I never notice the height difference, I'm sure
because the speakers I use have very good dispersion from side to side
(I lay them on their sides.)

Pans in and out of the center are very smooth sounding.

| You could try what I have done. Use a centre speaker on top of the
| TV together with the TV speakers ( if it has one on either side ).
| The net effect is to place the dialog _in_ the screen. It really
| does work! And little ( if any ) quality is lost since the centre
| speaker is still carrying half the load.

I expect that this would just confuse the ears and serve to defocus
the dialog and screw up the tonal balance. If this is working for you
then your problem all along been may have been a very low quality
center channel speaker.

A couple of days ago I heard a new center channel speaker by Profile
which sounded quite good for a very low ($149 CDN) price. They were
playing Star Trek V on laser, which is pretty good source material,
and I admit I was tempted.

But, I went home and listened to a brand new copy of Sister Act on VHS
and realized that my Mission 760's are still much better able to
handle the high sound levels that appear from time to time in
virtually any movie.

I believe that it really helps to get the best center channel you can
afford.
--
Kim Letkeman	kim@Software.Mitel.COM