HDTenEightyP/NetNews huggingface dataset:
From: kevins@eng.auburn.edu (Kevin Sullivan)
Subject: Crossover question
Organization: Auburn University Engineering
Date: Tue, 15 Dec 1992 14:07:27 GMT

Dig if you will the picture:

A 4 ohm tweeter with a 3.3 microfarad cap on the + terminal,
as a first order (6 dB/octave) high pass filter, -3dB cutoff
around 12kHz, right?

So I add this to my rear speakers of my van, but the tweeters 
are way too loud, relative to the woofer (yes I have a big hole 
in the midrange back there, the front speakers fill it in).  
So I put two 10 ohm 10 watt resistors in series with the cap, so 
I have:

amp + --------/\/\/\--------||--------- tweeter +
              20 ohm      3.3MFD
                                        (4 ohm)
amp - --------------------------------- tweeter - 

Does this not change my crossover frequency to 2000 Hz?  If so 
the system should sound terrible, but it sounds great (except 
for the lack of mids when running only the rear speakers).  What's 
going on here?

One more thing that might help or hinder analysis: this is the 
Chrysler/Infinity sound system, where low power speaker level 
signals are sent to the four corners of the vehicle.  This 
signal goes directly to the tweeter of a coaxial speaker and 
(in parallel) also to the input of a power amp for the woofer.  
There's a small amp on the back of each speaker.  Don't know 
the amp's input impedance but I'd guess pretty high relative 
to the tweeter.

Please help me figure this out.  It sounds great, I just don't 
want to blow the tweeters.

Newsgroups: rec.audio
From: dcovell@hfglobe.intel.com (David Covell)
Subject: Re: Good deals on scopes?
Organization: Intel Corporation
Date: Tue, 15 Dec 1992 20:01:23 GMT

Ted_Eugene_Viens@cup.portal.com writes:

>>
>>I'm looking for a source for a reliable scope at a nice price. I'm looking

>(Tucker Elec., Rag Elec., etc.) for used HP and Tek 50 to 100 Mhz models at
>Tucker Elec., Rag Elec., etc.) for used HP and Tek 50 to 100 Mhz models at
>about the same prices...

Please tell me more about the Tucker used scopes. Are they beat up? Do they
have some of the newer models?
From: law40001@nusunix1.nus.sg (CHENG KWONG WING)
Newsgroups: rec.audio
Subject: Amp/Speaker Question
Date: 10 Dec 92 01:27:40 GMT
Organization: National University of Singapore
X-Newsreader: TIN [version 1.1 PL6]


Could anyone please enlighten me on this:

1.  Whether a mixer (eg. Soundcraft) should be used as a pre-amp for a
home set-up?  Whether there would be a drop in sound quality if one
should do so?
> I currently have a Tandberg pre & power, and I've been playing around
with a mixer and feel that one can be much flexible with a mixer as a
pre-amp.  Oh, yes I'm referring to a mixer & an amp of about the same
price region.

2.  I'm been hearing my friend raving about his newly bought AMR
speakers & was wondering if anyone out there have any opinions about it?
I haven't heard the pair personally so I know nuts about it and I've
also never heard it mentioned on the net!

3.  I currently own a pair of B&W 801F, the original model not the
matrix version, and I find that the bass is not as tight as I would I
like it to be.  I saw some comments about putting it on stands and
spiking it.  Would all that really help?  As the costs of buying proper
stands and all that is pretty high, when I got the pair sometime back, I
only paid about US$1300 for it!

Thanks in advance for any replies.

--
--
____________________   .    .   __         . 
\______NCC_1701_____|) .____.--"--"---._____ 
             ||      /-----._________.----/  
     /=======||====/___/       "--"          
   . \==\____________|(-                .   
Newsgroups: rec.audio
From: whs70@dancer.cc.bellcore.com (sohl,william h)
Subject: Re: Digital-to-Digital copying
Organization: Bellcore, Livingston, NJ
Date: Tue, 15 Dec 92 15:03:36 GMT

In article <Bz9rCs.J7t@ssesco.com> nau@ssesco.com (William Nau) writes:
>Bill Sohl writes;
>>Now as to the legality of such equipmen, my understanding is it is OK
>>for "professional audio folks," but not the common riffraf audiophile :-)
>>Of course the determination of who is or isn't a pro has never been
>>tested in any court as far as I know.
>
>If it's legal for the pros, it's legal for common folk.  I don't believe
>that they need special Federal liscenses to make copies.  Please correct
>me if I am wrong, so I can bitch even more.

I don't think you're wrong either, but please don't bitch at me as
I'm just the messeneger :-) :-)

>As long as I'm at it.  Suppose I feed the digital signal into my home
>PC.  Is it illegal for me to clear those bits in my PC?  Can I then
>send those bits off to another DAT (or any digital recording device)?
>At what point is it wrong?  Does SCMS's existance make it illegal to
>bypass it?  What exactly does the law (if there is one) say?  Forgive
>me.  I know that all of this has been discussed before, but I guess 
>some of us were asleep.

I think it is all pretty fuzzy in terms of what, if anything, could
be done to prosecute, go after, sue someone for doing any of the
things you mention.  The very fact that there can exist "pro equipment"
that has no SCMS restrictions is a big loophole that would prevent
(IMHO) prosecution, etc.  As you also note, there's little that
could be done to establish that anyone is or isn't a pro...

The main goal of the federal laws was not so much the SCMS as it
is the establishment of royalty fees on blank DAT tapes and
DAT tape recorders (as well as other digital audio recording
media and equipment (DCC??,  MD???)

To get a copy of the law itself, contact one of your state senators
or your local congress critter and ask for a copy of the 1991
Home Recording Rights Act which was passed by congress and signed
by Bush within the last 2 months.

Standard Disclaimer- Any opinions, etc. are mine and NOT my employer's.
-----------------------------------------------------------------------
Bill Sohl (K2UNK) BELLCORE (Bell Communications Research, Inc.)
Morristown, NJ             email via UUCP      bcr!cc!whs70
201-829-2879 Weekdays      email via Internet  whs70@cc.bellcore.com
From: chrz@tellabs.com (Peter Chrzanowski)
Newsgroups: rec.audio
Subject: Re: Amp classes  was: Re: A/V Pro-Logic receiver: Onkyo or Technics ?
Date: 11 Dec 92 18:32:43 GMT
Organization: Tellabs, Inc.

In article <Mf8PI4_00WAt8O_Hdg@andrew.cmu.edu>, Martin David Frankel <mf3s+@andrew.cmu.edu> writes:
> 
> Can someone describe the differences between these classes a little more
> fully?  From a technical as well as a sound quality standpoint?  I'd be
> eternally grateful. Or just point me to a good reference on the subject.

Horowitz and Hill, _The Art of Electronics_, is a good introduction to 
practical electronics.  It's kinda expensive (~$40.) but has been through
many editions, so you might be able to get a cheap used one. 

In a class B amplifier, there are at least two output devices but only
one is conducting at any given time -- one conducts when the output is
positive, the other when it is negative.  An amplifier of this type
has a theoretical efficiency of 70.7%.

Most audio amplifiers have class AB output stages; these are similar to
the above, but both devices conduct a little bit when the output is
near zero.


> 
> I once saw an amp that claimed to be "Class AA".  What does THAT mean?
> 

The "traditional" amp classes are A, AB, B, and C (with class D generally
referring to some sort of pulse-width modulation scheme).

The other "classes" tend to have non-standard, manufacturer defined meanings.
For example, some amps have an extra "booster" power supply that charges
capacitors which can be used to deliver a lot of extra power for a very
brief period of time.  
>             -- Martin
Newsgroups: rec.audio
From: stuart@uwa.oz.au (Mather)
Subject: Re: Amp classes was: Re: A/V Pro-Logic receiver: Onkyo or Technics ?
Organization: Elec Eng, Univ of Western Australia
Date: 17 Dec 92 01:36:47 GMT

grego@bit.UUCP (Greg Sanguinetti) writes:

>In article <Mf8PI4_00WAt8O_Hdg@andrew.cmu.edu> mf3s+@andrew.cmu.edu (Martin David Frankel) writes:
>>I once saw an amp that claimed to be "Class AA".  What does THAT mean?

>It's battery operated     ;^)

>sorry couldn't resist.
>-- 
>>>Never heard of it. Probably a marketing gimmick. Can't be "Class A"
>>>A 100watt "Class A" would have heatsinks the size of a large bathtub!
>>>Well... almost :)
>---------------------------------------------------------------------------
>Grego Sanguinetti, Bipolar Integrated Technology | Water, water everywhere,
>grego@bit.uucp or grego%bit%ogi.cse.edu          | but I'd rather drink
>or bit!grego@ogi.cse.edu or ...!ogicse!bit!grego | beer.
Newsgroups: rec.audio
From: dmd39855@uxa.cso.uiuc.edu (Daniel DuBois)
Subject: Re: DCC and MD Quality
Organization: University of Illinois at Urbana
Date: Sat, 19 Dec 1992 00:52:19 GMT

owen@emds.enet.dec.com (Steve Owen) writes:


>In article <1992Dec17.192744.86020@ns1.cc.lehigh.edu>, jap1@ns1.cc.lehigh.edu (JOSEPH ALEXANDER PADULA) writes...
>>It is a sad day indeed when "CD quality" is the aspiration for new media. 

>Agreed... but 99% of the audio buying public has already been suckered into 
>thinking that CD sound is the be-all end-all of sound quality.  They are 
>mistaken.

>Later...
>Steve

I'm not an audiophile.. Is there something better than CD?  Are you
referring to live performances or something?

-Dan
Newsgroups: rec.audio
From: sloan@iastate.edu (Eric R Sloan)
Subject: Inexpensive speaker driver souce
Organization: Iowa State University, Ames, IA
Date: Wed, 16 Dec 1992 21:56:34 GMT

Sorry, I would have e-mailed but I lost the article.........

The best place that I have found for inexpensive drivers is

Parts Express out of Dayton OH.  They have a large selection (IMHO)

of raw drivers and kits. Also some assorted electronics and auto-sound.

I placed an order with them about 2 weeks ago for a pair of tweeters 

(due to a bad bi-amping experiment, some people may remember..)

Anyway the prices are decent and I ordered on Mon. and got the stuff Fri.

    Parts Express
    340 E. First St.
    Dayton OH, 45402       1-800-338-0531


-------------------------------------------------------Eric Sloan---------------
From: lstowell@pyrnova.mis.pyramid.com (Lon Stowell)
Newsgroups: rec.audio
Subject: Re: hooking portable CD to tape-less car radio
Date: 11 Dec 92 18:41:28 GMT
Reply-To: lstowell@pyrnova.pyramid.com (Lon Stowell)
Organization: Pyramid Technology Corp., Mountain View, CA

In article <Dec.9.21.00.45.1992.13883@athos.rutgers.edu> borgida@athos.rutgers.edu (Alex Borgida) writes:
>
>I have a Toyota without a tape deck, but with a radio and speakers
>that I am quite happy with. I also have a portable CD player that I
>use in the garden, at work, etc. I was told by a local "car stereo"
>place that it is *not* possible to hook up wires to the car radio so
>that I can listen to my portable CD player in the car, when I go on
>long trips. 
   '
   This is somewhat true, it would be difficult.  The typical
   inexpensive car radio doesn't have any extra inputs for hooking
   up such things as tape decks, CD players, etc.  

   Since the unit doesn't have the extra's, I'll make the assumption
   that it is not one of Toyota's higher end units...and the sound
   quality would not really do justice to the output of a player
   anyway.  

   You might be able to use your player if you can find a small
   cheap FM modulator and hook it up to the output of the
   player...tune the radio to an unused station, and listen.  But I
   expect that would be more expensive than upgrading the system to
   one with a tape deck....then you can use a CD to cassette
   emulator and get reasonable sound...since you'd be keeping your
   current speakers.

>They said I would have to buy a "changer", I think the
>kind that goes in the trunk.
>
   That may or may not be pure BS.  It may be that you don't have
   ROOM in your car for a CD player in the dash....

>Can someone please explain why not? If it is lack of proper
>amplification, is it possible to buy a "cheap" amplifier and hook that
>to the wires going to the car's speakers?  Why is it so hard to tie
>wires to the ones coming out of the radio and going to the speakers?
>
   Yes, you could buy a cheap amp and hood it to the earphone out of
   your CD player and hook it to your speakers.   If you need the
   radio, install a pair of switches in the speaker wires so you can
   select the CD/amp or your radio.   

   This may be your cheapest answer.  
Newsgroups: rec.audio
From: jcd@punch (John C. Davis)
Subject: Help? Surround Sound Amplifiation Suggestions
Organization: The Aerospace Corporation; El Segundo, CA
Date: Fri, 11 Dec 1992 22:38:55 GMT

I have an investment in my stereo and would like to upgrade to Dolby Pro  
Logic without scrapping my initial investment. I would like suggestions on  
how to add amplification to my system. (eg integrated amplifier w/ Pro  
Logic, Pro Logic w/o amplification and seperate amplifier etc...)

My current system is:

Adcom GTP 500? Remote Control Preamplifier
Carver 1.0t Amplifier
B&W DM 220 Speakers

Any suggestions would be appreciated?
John C Davis
jcd@punch.aero.org
Newsgroups: rec.audio
From: georgen@gpu.utcs.utoronto.ca (G. Ng)
Subject: Re: dt990 pro and sennheiser hd560: any recomendations?
Organization: UTCS Public Access
Date: Sun, 13 Dec 1992 15:25:28 GMT

In article <1992Dec13.065916.11555@julian.uwo.ca> janik@gfx.engga.uwo.ca (Janik Joire) writes:
>	I own a pair of Beyer Dynamic DT-990. When I auditioned different
>pairs of headphones and decided on the DT-990, no other model came close!

I agree.  I too bought a dt990 several years back.  I'm sure the performance
of BD's dt990 pro (and perhaps their new dt911) are just as good if not
better.

>without any noticable pull. In my honest opinion, the DT-990 could just be
>the *best* pair of electro-dynamic headphones in that price range.

They most likely are.  Short of buying some expensive Stax electrostatics,
in the dynamic market, BD's are the best if not *the* best.

gn
From: mjf9968@rigel.tamu.edu (Pi(3.143832666))
Newsgroups: rec.audio
Subject: tweaks for cheap speakers
Date: 12 Dec 1992 22:56 CST
Organization: Texas A&M University, Academic Computing Services
Distribution: world
NNTP-Posting-Host: rigel.tamu.edu
News-Software: VAX/VMS VNEWS 1.41    

	I wanted better bass response out of my el-cheapo
Yamaha speakers (model NS-4), so I pushed them back against
the wall.  (They had been sitting out about 8-10 inches from
it.)  Voila!  More bass.
	Now, however, I'm really noticing how "mushy" the
bass is.  Was the bass always this mushy, and I just didn't
notice it before?  Or is this another effect of the speakers 
being closer to the wall?  And most importantly, is there 
anything I can do to "tighten" up the bass, without losing too 
much of the response, that will cost very little?  (If I had 
money I'd just buy some better speakers.)
	In other words, I want a free lunch.
	Any suggestions?

	Living better through chemistry,
	Mike "Pi" Freeman
	MJF9968@rigel.tamu.edu
Newsgroups: rec.audio
From: mlm2@crux1.cit.cornell.edu (Mark Lee Margolis)
Subject: Parasound 1200, 2200 amps
Organization: Cornell Information Technologies
Date: 18 Dec 92 04:06:04 GMT

Anyone own or have any experience with the Parasound HCA-1200 or HCA-2200 
amps? I am thinking of upgrading (yet again) from the Parasound HCA-800II
to a more powerful amp, and I was wondering what people thought or have heard
of those more powerful amps, especially in comparison to the 800-II and other
high end amps.

- Mark

--
**********************************
Mark L. Margolis
mlm2@crux1.cit.cornell.edu
fnox@vax5.cit.cornell.edu
Newsgroups: rec.audio
From: kong@leland.Stanford.EDU (Kong Kritayakirana)
Subject: Shine On
Organization: DSG, Stanford University, CA 94305, USA
Date: Fri, 18 Dec 92 02:14:30 GMT

Recommended for PF fans: "Shine On"
Improved sound quality over previous releases. 9 CDs total. Nice book
and postcards.

Newsgroups: rec.audio
From: billn@hpcvaac.cv.hp.com (bill nelson)
Subject: Re: Hopefully New MD Questions
Organization: Hewlett-Packard Company, Corvallis, Oregon USA
Distribution: rec.audio
Date: Sun, 13 Dec 1992 12:12:38 GMT

jj@alice.att.com (jj, curmudgeon and all-around grouch) writes:
: In article <1992Dec8.065649.13579@hpcvaac.cv.hp.com> billn@hpcvaac.cv.hp.com (bill nelson) writes:
: >deleon@adobe.com (Michael de Leon) writes:
: >: All in all it sounds and looks like a winner but a few questions remain
: >: in my mind.
: >: Is the duplication of a regular CD to MD exact?
: >As to sound, yes. As to exact, no. There is one bit in (each byte of?) the
: >data stream that is changed. I keeps you from using that copy to make other
: >digital to digital copies. Of course, if the tape/disc you want to copy
: >already has that bit set - then you will not be able to make the first copy.
: This is complete misinformation.  MD uses a lossy compression algorithm
: to compress the bit rate of the audio signal to a lower rate that
: can be stored and recovered from the MD in real time.

Not misinformation - just poorly stated. To most people, the copy will sound
the same as the original. Critical listeners may, or may not, be able to
consistently tell which sounds better. The copy will not be exact, for the
reason you stated. That is what I meant.

: This is completely independant from the SCMS issue that billn answers.
: The question of the quality of the MD compression algorithm is still
: unanswered, but Sony admits that it is not "CD quality" but rather
: "close to CD quality".
: 
: Two trips through the MD encode and decode will very likely
: sound worse than the original.  This issue has already been
: dispusted and laid to rest in this newsgroup.

Two trips? One trip through the encoder to record. One trip through
the decoder to play. Or are the manufacturers making thing unnecessarily
complicated?

: >The copy protect circuitry is already there - see above. You still will
: >be able to make digital to analog to digital copies - with attendent
: >degradation.
: This is, of course, also wrong.  Even a PCM digital to PCM digital
: copy will show degredation because of the compression algorithm.

How? If you are copying a stream of digital bits, then you do not go
go through a decode/encode cycle. There is no need to do so to make
a digital to digital copy. Whether the manufacturers do so is another
matter. You should be able to take a CD and make a digital tape that
matches the original bit-for-bit (except for error correction to  
correct defects in the original recording).

Bill
From: wdh@grouper.mkt.csd.harris.com (W. David Higgins)
Newsgroups: rec.audio
Subject: Re: Sony ES vs. Sony A/V receivers
Date: 14 Dec 92 19:08:59 GMT
Organization: Harris CSD, Ft. Lauderdale, FL

In article <bsj2r!r@rpi.edu> monitn@rebecca.its.rpi.edu (Nicholas Monitto) writes:
>2ftntold@kuhub.cc.ukans.edu writes:
>
>>After reading a favorable review on the Sony STR-GX99ES A/V receiver, I
>
>The STR-GX99ES is 120x2F [stereo only] or 75x2F, 75C, 60surround [probably 30
>per channel] when run in surround.

I'd read the fine print.  A friend purchased a Sony AV receiver this
weekend and called up to ask what the phrase "8 / 16 ohm speakers only"
meant.  It wasn't clear if this was true for all 5 channels, or only for
the surround amps.  He has 4 ohm speakers (B&W 620s, I think).

What it means, BTW, is Sony skimped on the output stage of the receiver.
Even a nominal 8 ohm speaker may have frequencies where it presents a
lower impedance load to the amp.  An amp should have enough current
capability to drive 4 ohm loads.  Amplifiers are rated driving
8 ohm resistive loads.  Real life loads (speakers) are different.

In any case, be careful when purchasing a receiver.  Don't
concern yourself too much with wattage ratings (you'll never hear 
the difference between 45 and 50 watts a channel, all other things
held equal).  I'd much rather have a 40 w/ch amp that could drive
4 ohm loads @ 80 w/ch than a 60 w/ch amp that shuts down trying
the same thing.
Newsgroups: rec.audio
From: bill@bilver.uucp (Bill Vermillion)
Subject: Re: Do I really need 200W?
Organization: W. J. Vermillion - Winter Park, FL
Date: Mon, 14 Dec 1992 02:47:12 GMT

In article <1992Dec10.165802.318@siemens.co.at> howdii@patty.gud.siemens.co.at () writes:

>You have to decide yourself, if you need really 200W. 
>Here some examples:
>e.g., you have a speaker with a SPL of 90 dB/W/m. (SPL = sound pressure level)
>To sense, that music is louder, you have to power up for 3 dB.
>To get music louder for 3 dB, the amplifier must send double power to
>the speakers as in the moment before.
>
>So here is a list of SPL and W according to the example:
>
>   1W ....  90 dB
>   2W ....  93 dB
>   4W ....  96 dB
>   8W ....  99 dB
>  16W .... 102 dB
>  32W .... 105 dB
>  64W .... 108 dB
> 128W .... 111 dB
> 256W .... 114 dB
> 512W .... 117 dB
>1024W .... 120 dB
>
>I suppose, a HIFI-speaker with a SPL of 90 dB/W/m can reach a max. SPL of
>about 110 dB/W/m before beeing destroyed by overpowering. At least, 120 dB
>will let your ears tingle. You see, Watts are not all. 10 W with the speaker
>described above will be about 100 dB, and this is much noisy in a normal
>room. 

(rest of the paragraph deleted).

Using the above figures - and given that you want to reproduced the
recorded sounds as accurately as recorded, 200 W should be about the
MINIMUM power you would want, if you listen to anything with transients
and run about 95db in a listening environment. 

When in the studio I had great opportunity to observe the differences
between average power and peak power.   Most transients come in at
about 10db over normal signal, but I have seen cases, typcially
percussive instruments used in jazz, where 20db peaks have been seen.

If the recording were digitally recorded, and these were not clipped
during input or recording,  and your typically power to the speakers
was 4 watts, to be able to maintaing a 20db transient with no clipping
(eg distortion) you would need over 250 watts for an instant.  

Most amps used to be able to handle a quick transient at about double
the rated power, but lately most amps I have seen give only a 2b
headroom over rated power.

My systems have always had fairly efficient speakers, driven by amps
that were capable of large amounts of power, but run almost at 'idle'.

I typically run about 2 watts to my speakers, and have lots of
headroom.  I put about 96 db at the listening position - 10-12 feet
from the speakers with this amount.


-- 
Bill Vermillion - bill@bilver.oau.org  bill@bilver.uucp
                - ..!{peora|tous|tarpit}!bilver!bill
From: "herb chong" <herb.chong@channel1.com>
Newsgroups: rec.audio
Subject: mobile fidelity....
Date: 18 Dec 92 04:59:54 EST
Reply-To: "herb chong" <herb.chong@channel1.com>
Distribution: rec
Organization: Channel 1 Communications

SS=>I thought the gold made a better surface for the laser to ride on,
  =>producing less of a need for error correction.

in the sense that the gold is essentially corrosion proof, yes.

Herb...
---
  OLX 2.2  At the prompt, remove disk, spit on it, then retry.
--
Channel 1 (R)   Cambridge, MA