HDTenEightyP/NetNews huggingface dataset:
Newsgroups: rec.audio.car

>kirk@hpcc01.corp.hp.com (Kirk Lindstrom) writes:
>> Bolt is in fact a "Class A" amplifier, but my guess is it is a reference
>> to their input stage in the hopes of fooling people.  A true class-A
>> output amp for car audio is ludicrous.  Next we'll get tubes!  I
>> 
>> Kirk out
>
>Class A in a car is not possible in an output stage from what I have
>read... still looking for the source, though I suspect Autosound 2000.

Well, anything is possible.  It would be fairly easy to make a low power
true class-A amp for auto use, just few would buy it as the speakers to
appreciate it aren't that common and most wouldn't buy it since the "spec's
were so poor" i.e. not enough wattage for the avg boomer.  The better home
amps I've listened to lately are class-A for up to maybe 25 watts and then
switch into AB operation which is a neat trick.

>As for tubes, Milbert introduced their BaM-230 about 4.5 years ago.
>It is a $2000 (list) 30 watt per side tube amp using 6JN6 output
>tubes.  The problem with tubes in autosound had to do with the high
>voltage needed to drive them, but this baby is supposed take care of
>the problems with an impressive p/s.  I'd love to get my hands on one!
>
I've seen pictures of tubes in cars.  I wounder how long the filiments last if 
you drive over rough roads with sports-car or even van suspension?  High
voltage is OK, your coil does just fine, it just tubes aren't very efficient
and the way to make money in car audio is to squeese as much delivered power
as possible out of alternators and batteries.

Thanks for the info.
>\ Jason A. Reiser  \ Send E-Mail to jreiser@scott.skidmore.edu \
>---------------------------------------------------------------

Kirk out
=> "We are what we pretend to be."  -  Kurt Vonnegut Jr.
+---------------------------------------------------------------------+
| Kirk Lindstrom - OCD Product R & D | Hewlett-Packard Co.  M/S: 91UA |
|   Engineer/Scientist, Hardware     |                                |
|------------------------------------| Optical Communication Division |
|     kirk_lindstrom@sj.hp.com       |                                |
|    Kirk Lindstrom / HP0100/UX      | 370 W. Trimble Rd.             |
| ph 408 435 6404 | fax 408 435 6286 | San Jose, CA  95131-1096       |
+---------------------------------------------------------------------+

Newsgroups: rec.audio.car
From: blasjw@ntmtv.UUCP (Joseph Blas)
Subject: Where is PerfectBox? - 2nd try 
Reply-To: ntmtv!blasjw@ames.arc.nasa.gov (Joseph Blas)
Organization: Northern Telecom Inc, Mountain View, CA
Date: Mon, 21 Dec 1992 22:19:49 GMT


This is my second attempt in trying to locate PerfectBox which is a
speaker design program.  Could someone please tell me an ftp site
where I can find it.  I don't relly know how to use archie so that's
no help.  BTW this program is shareware.

	     Thanks in advance,

		       Joe


Joseph W. Blas    
ntmtv!blasjw@ames.arc.nasa.gov
Northern Telecom
Mt. View, CA
From: system@hale.cts.com (System Administration)
Newsgroups: rec.audio.car
Subject: Re: Rattles
Date: 1 Jan 93 01:10:03 GMT
Organization: Hale Telecommunications Inc.

kchau@fraser.sfu.ca (Kwok Kwong Albert Chau) writes:

> Anybody know of a good way to eliminate rattles from panels in the 
> passenger compartment?  Even with the screws good & tight, I get a 
> most annoying rattle from certain panels in the dash area.  I would
> think that there's plasticine type material for this purpose.  The 
> questions are what's it called, where can i get it, & how much $$.


You can use alot of different things, here's some we use at work 
depending on exactly what's happening....

Fiberglass insulation as a backing (Apply with contact cement.)

Rubber Grommets between the panel and chassis at the screw hole.

Thin sheets of uplostry foam.

Foam Insulation, in a can from your local hardware store.  Just feed the 
hose behand the panel and give it a quick shot.

If screws or bolts rattle loose, use thread-lok or teflon tape (on the 
threads) like that is used on natural gas pipes.

This should at least spark some ideas of your own.....
Newsgroups: rec.audio.car
From: mgarber@magnus.acs.ohio-state.edu (Max D Garber)
Subject: Re: Mail order companies/addresses
Organization: The Ohio State University
Distribution: rec
Date: Wed, 30 Dec 1992 17:13:41 GMT


I would like to have such a list as well.
-- 
1983 Pontiac 2000 SE   1986 Mercury Topaz GS     1983 Honda NIGHTHAWK 650
    'BABY BOOOM'          'MS. BABY BOOOM'           'MINT CONDITION'
"Car-Audio for Sale"     Under Construction     "Bike For Sale-Make Offer"
       'HIS'                   'HERS'                    'THEIRS'
From: wrob@unixg.ubc.ca (Robert Wong)
Newsgroups: rec.audio.car
Subject: Re: Temperature in car CD player
Date: 1 Jan 1993 10:47:58 GMT
Organization: University of British Columbia, Vancouver, B.C., Canada
Distribution: world
NNTP-Posting-Host: unixg.ubc.ca

In article <C04u57.BAI@usenet.ucs.indiana.edu> bhostetl@silver.ucs.indiana.edu (Brian Hostetler) writes:
>	When I pull my CDs out of my Pioneer after a few songs, 
>they are incredibly hot.  Have there been any studies on whether 
I've got the same problem w/my Panasonic CS shuttle deck.
 RWW.


-- 
Robert W. "What!?! I've-been-tying-my-shoelaces-backwards-all-my-life?" Wong Jr.
wrob@unixg.ubc.ca (ASCII only)
Newsgroups: rec.audio.car
From: brian@tunica.eel.ufl.edu (Brian Gentry)
Subject: Re: dB, volts vs. watts (was Re: Why so much power?
Organization: UF EE Department (student)
Distribution: na
Date: Sat, 2 Jan 93 20:44:15 GMT

There seems to be a lot of confusion about what dB is.  dB is a power
ratio.  This is very important so I'll say it again:  dB is a power
ratio.  Terms like dBV and dBW don't really have any meaning.  Before
I'm attacked let me explain.  The DEFINITION of dB is:

dB gain = 10 * log{base 10}[power_out/power_in]

So, if you have a black box with a set of input terminals and a set of
output terminals you can measure the dB gain from one port to the other
(a port is two terminals which voltage is applied to).

The confusion comes when you don't have a watt-meter to measure the power
with.  Most engineers know the formulas V=I*R and P=I*V.  You can combine
these to get P = V^2/R.  Substituting this for the powers in the definition
of dB you get:

dB gain = 10 * log[(Vout^2 * Rin) /(Vin^2 * Rout)]

Now if (and only if) the input resistance (Rin) is equal to the output
resistance (Rout), they cancel leaving us with:

dB gain = 10 * log[ Vout^2/Vin^2 ] 

This simplifies (using laws of logarithms) to:

dB gain = 20 * log[Vout/Vin]

Unfortunately most manufacturers and engineers have forgoten that the 
output resistance MUST be equal to the input resistance in order to
use this last form.  Because of this, we get lots of meaningless units
like dBV.  To be fair, dBV does tell you the ratio of voltages--and this
is useful.  Unfortunately dBV has very little relation to the definition
of dB.  dBV is NOT a POWER ratio.

To add even more confusion, acoustical phenomenon are quantified using
dB.  So we see formulas for SPL that contain 20 * log[Pressure1/Pressure2].
This formula doesn't really measure a power ratio of any black box.  It
compares a measured pressure to a reference pressure.  This reference pressure
is assumed to be radiating in the the same ACOUSTIC impedance as the pressure
being compared.  This should hold true for any measurement made in full space
at close to standard temperature and standard pressure.  (25 deg. C and 1 atm).

As someone else mentioned "dBA" is an A-weighted measurement of SPL.
A-weighting is only valid for SPLs in the vicinity of 60 dB.  This makes
it very inappropriate for most real world audio situations.  Because it
rolls of the highs and the lows, it can make a piece of noisy equipment
seem less noisy by lessening the effects of the high and low frequency 
noise.  Manufacturers the specify any of their ratings in dBA are not
showing the whole picture.

			Brian L. Gentry
		    (brian@sioux.eel.ufl.edu)
Newsgroups: rec.audio.car
From: swu@att.com (Chi-Sharn Wu)
Subject: Turing on radio creates buzz ?
Originator: news@cbnewsb.cb.att.com
Reply-To: swu@probe.att.com
Organization: AT&T Bell Laboratories
Distribution: usa
Date: Thu, 31 Dec 1992 14:19:12 GMT

After I installed a CD changer to my Maximum GXE 92 last week, I just 
noticed that depressing the accelerator pedal will create little  high-frequency buzz if I turned on the radio or CD changer.
I don't know where it comes from.
I will appreciate if anyone can explain the problem.

---

Chi-Sharn Wu
swu@probe.att.com
From: Berger@cup.portal.com (Mark - Berger)
Newsgroups: rec.audio.car
Subject: Sony UniLink head unit with 13-pin changer?
Date: Tue, 22 Dec 92 13:39:29 PST
Organization: The Portal System (TM)
Distribution: usa


I have a Sony A30 CD changer in my trunk and a hole in my dash!

Local stereo retailers have told me that the new generation of Sony UniLink 
stereos cannot be used with the older 13-pin changers.  However, a fellow
at Sound City (a mail order shop) says he will soon be receiving a plug
from Sony to connect the two.  He did not have a model # yet.  Sony has no
knowledge of this, but the customer service guy I talked with thinks its in
the works (unofficially, of course).  Apparently the marketing department
has to make a decision.

I would love to buy a new UniLink head unit, but I don't want to buy a new

changer for no reason.  

Those of you who follow the car audio press may know:  Any rumblings in the
wind?

My fall back, of course, is to buy a Blaupunkt or similar tuner which can
control my older changer, but I think their ergonomics leave a bit to be
desired.  

I appreciate any wisdom you can share.
Newsgroups: rec.audio.car
From: bruce@pages.com(Bruce Henderson)
Subject: Re: DAT availability
Organization: Banzai Research Institute
Distribution: usa
Date: Wed, 23 Dec 1992 17:58:50 GMT

In article <22DEC199212403049@vx.cis.umn.edu> daven@vx.cis.umn.edu (David  
Nieters) writes:
> Does anyone know if there are DAT players still being made for the
> automobile?  If so, where can I get information on them?
> 
> David Nieters
> University of Minnesota
> daven@vx.acs.umn.edu

I am sorry to hear that.  I currently have a Kenwood KDT 99R in my CRX and I  
have a Sony DTX-10 in my other car.  I purchased the Kenwood first, about 2  
years ago.  I am very happy with it.  Sadly enough it is no longer being made.   
I bought the DTX-10 a year later, I am not as happy with it.  But it still more  
or less serves it purpose.  I had to go to great lengths to bash one out of  
Sony because they were not making them any more.  Car DAT decks are not  
available in the US as of this time.  You have 3 options

1)	Find and buy a used one
2)	Get a portable DAT walkman (like Sony's DTC-D3)
3)	Buy a "Grey Market" japaneese unit.Some models are

Sony 		DTX-10  120,000 Yen
ADDZEST		DAC-700  98,000 Yen
ADDZEST		DAT-909 198,000 Yen

Hope this helps

Bruce
Newsgroups: rec.audio.car
From: sykes@donner.cc.bellcore.com (sykes,michael)
Subject: 88 Prelude CD player problems
Organization: Bellcore, Livingston, NJ
Distribution: usa
Date: Wed, 23 Dec 92 21:05:20 GMT

Hello,

This is my first post but I figured that this is the place to get some
help. 

I have an 88 Honda Prelude with a factory CD player. (I bought the car used)
The CD player doesn't work. It will take the disc in but it will not play.
Is there a replacement I can get for just the CD player alone? The tape
deck is below the CD and they are seperate units. If I can just replace
the CD player this would be the eaisest answer to the problem.

Suggestions are welcomed!!!
E-mail direct if you like, I don't read this group often.

Thanks,

Mike

-- 
Michael H. Sykes
Standard disclaimers apply
sykes@donner.cc.bellcore.com
"It was like that when I got here" - Homer J. Simpson
Xref: sparky rec.audio.car:5518 misc.forsale:34359
Organization: University of Central Florida--Computer Services
Date: Thursday, 31 Dec 1992 00:45:42 EST
From: Stanley Tong <STONG@UCF1VM.BITNET>
Newsgroups: rec.audio.car,misc.forsale
Subject: 4Sale: Pioneer CD-contrl/Cass/Tuner; EQ

I am posting this for a friend who does have access to netnews,

For Sale:
     Pioneer KEX-M800 Component Multi-CD Control Full Logic Cassete deck
     with Detachable Face Security.
             Super Tuner III
             18FM/6AM Presets
             32Track/16 Magazine Programmability
             2 acoustic memories
             etc.
          Just check with any Pioneer dealer on more features and price.

      ASKING $395 (obo)

 ALSO For Sale:
     Pioneer EQ-6500 9-Band Graphic Equalizer
             with Post-EQ Crossover Network and Subwoofer Output

      ASKING $195 (obo)


 **** WILL SELL BOTH FOR $550 (again obo)  ****

Please send replies
         E-Mail to  stong@ucf1vm.cc.ucf.edu
                or
         call Mike (owner) at (407)275-0086


     Thanks............
From: jzerden@pro-cynosure.cts.com (Jon Zerden)
Newsgroups: rec.audio.car
Subject: Re: Where is PerfectBox? - 2nd try
Date: 31 Dec 1992 01:31:48 -0600
Organization: ProLine [pro-cynosure]
NNTP-Posting-Host: cs.utexas.edu

Well all.. due to malfunctions on the BBS's I have lost the messages for
the last couple of days.. If I have not replayed to you, please try again!

Still for sale: JVC-KSRG8 head unit - detachable face, 2 color illum, cd
controlls.. EVERYTHING! $285.00 (a $420.00 head unit) brand new IN BOX (I
even have a receipt!)

Jon Zerden                         Sysop Of Triumvirate BBS
InterNet: JZerden@pro-cynosure.cts.com          410-486-9812
CI$ 73520,167                      Genie: J.Zerden
                FutureNet #1@#11
Newsgroups: rec.audio.car
From: jdavis@wizard.etsu.edu (Jason Davis)
Subject: Re: Why so much power?
Reply-To: jdavis@wizard.etsu.edu (Jason Davis)
Organization: East Texas State University, Commerce, TX
Date: Wed, 23 Dec 1992 06:41:23 GMT

...something else to consider for automotive power requirements is the
variable noise floor present in automobiles.  The need for ample headroom
is made even more crucial by the high noise floors in some vehicles.  It
is well established that a system will run more efficiently when there is
more power available than the speakers normally require to operate at a
comfortable listening level.  This is known as headroom which allows the
amps to run cooler and safely below the voltage rails of the amplifier.
When you do things in a car such as rev the engine, drive with the windows
down, etc. you increase the amount of ambient noise (noise floor) perceived
in the interior.  It is therefore necessary to have amplifiers with enough
headroom to allow you to increase the volume enough to compensate for the
increase in noise so it can be heard.  I know that driving at 80mph with
my windows down with the twin firestick antennae and dual-band HAM antenna
on my truck it takes most of the 695W I'm running in my truck to overcome
the wind noise.

   Hope this helps clarify neighbor :-)  (Dallas to Klondike = 65 mi. N.E.)

-Jason Lee Davis

)
   /|  Jason Lee Davis                        <jdavis@wizard.etsu.edu>  |\
||/_|  Shiloh Productions sound co. ____      <s2903d@etsuv2.etsu.edu>  |_\||
||\ |  Rt. 1  Box 175              (_ |_)     <s2903d@etsuvax2.bitnet>  | /||
   \|  Klondike, Texas 75448 ________)| _____ (903) 886-2903            |/
From: kist@acsu.buffalo.edu (james e kist)
Newsgroups: rec.audio.car
Subject: DCC
Date: 24 Dec 92 21:21:30 GMT
Organization: UB



Could somebody tell me exactly how Digitally Coded Cassettes differ from
DAT? I mean, since DAT has failed, how can any manufacturer possibly think
that they're going to get anywhere with this format? 
From: kirk@hpcc01.corp.hp.com (Kirk Lindstrom)
Date: Sat, 26 Dec 1992 14:52:54 GMT
Subject: Re: Why so much power?
Organization: Shredding the water of SF Bay, HP-OCD
From: daven@vx.cis.umn.edu (David Nieters)
Subject: DAT availability
News-Software: VAX/VMS VNEWS 1.41    
Organization: University of Minnesota CIS
Distribution: usa
Date: Tue, 22 Dec 1992 17:40:00 GMT

I had an Apline 5900 DAT player in my car up until a year ago when the
whole car was stolen.  When the police recovered the car, all the stereo
equipment was gone.  I've been looking to replace the DAT player this
summer, but it seems that manufacturers are getting out of that market,
including Alpine.

Does anyone know if there are DAT players still being made for the
automobile?  If so, where can I get information on them?

David Nieters
University of Minnesota
daven@vx.acs.umn.edu
From: jzerden@pro-cynosure.cts.com (Jon Zerden)
Newsgroups: rec.audio.car
Subject: Pagers
Date: 26 Dec 1992 12:57:04 -0600
Organization: ProLine [pro-cynosure]
NNTP-Posting-Host: cs.utexas.edu

Does anyone have any expierence with Car Alarm Pagers? I have looked at
both Alpine and AutoPage.. but don't know whats the best.

ANy suggestions?

Jon
Jon Zerden                         Sysop Of Triumvirate BBS
InterNet: JZerden@pro-cynosure.cts.com          410-486-9812
CI$ 73520,167                      Genie: J.Zerden
                FutureNet #1@#11
From: f4ax@vax5.cit.cornell.edu
Newsgroups: rec.audio.car
Subject: Re: Mail order companies/addresses
Date: 29 Dec 92 15:57:21 EST
Distribution: rec
Organization: Cornell University

In article <1992Dec28.204101.209@csc.ti.com>,
ajones@dadd.ti.com (Alan Jones) writes: 
> I recently saw one or two postings which had the names and addresses of some
> good mail order companies which market car audio components.  Would someone be
> so kind as to post (or email) the names and addresses?
> 
> Also, does this newsgroup have a FAQ?  If so, whar is it???
> 
> ---
> sincerely,
> Alan Jones  /  Texas Instruments, Dallas, TX  /  email=ajones@tiasic.csc.ti.com
> 

Ditto.  I've been looking for a list since last summer!

Jason
From: boing@mcl.ucsb.edu (Geff Hanoian)
Newsgroups: rec.audio.car
Subject: Re: Crossover question
Date: 3 Jan 93 07:08:47 GMT


	Well only a minor problem would be that your amp is 
	being driven @24ohms (or so).

	boing
--
----------------------------------------------------------------------------
|             DISCLAIMER!!!!!!  The opinions I express are my own.         |
|  Nakamichi, Precision Power, AVI SOUND, and Monster Cable Speaker Wire.  |
|        boing@mcl.mcl.ucsb.edu   FRIENDS DON'T LET FRIENDS USE MACS!      |
From: tom@math.ufl.edu (Thomas J Gillen)
Newsgroups: rec.audio.car
Subject: Toshiba CD changer:  any good?
Date: 21 Dec 92 18:38:23 GMT
Organization: University of Florida Department of Mathematics



	I recently saw (at Sam's, no less!) a Toshiba 6-disc changer
with FM-connector for $289.00.

	The price seems ridicuously low, and I'm just wondering if, as
I fear, I'll be getting what I pay for! 

	I don't remember the model number (TX-900?), but I'm sure
there can't be many Toshibas for near that price.

	But if anybody has any opinions, warnings, or advice, I'd
appreciate the info.

	Regards,

	Tom
From: kirk@hpcc01.corp.hp.com (Kirk Lindstrom)
Date: Wed, 23 Dec 1992 17:14:50 GMT
Subject: Re: Why so much power?
Organization: Shredding the water of SF Bay, HP-OCD
From: demaine@ee.ualberta.ca (Cal Demaine)
Subject: Re: Isobarik subwoofer design
Organization: University Of Alberta, Edmonton Canada
Distribution: usa
Date: Wed, 30 Dec 1992 09:12:15 GMT

jsvec@umaxa.weeg.uiowa.edu writes:

>I want to build a subwoofer, and have more or less decided to try an 
>Isobarik design using two Madisound 12" woofers.  I was just wondering if
>anyone out there has had experience/luck in building Isobarik boxes and/or
>has any comments about Madisound drivers.

Well, I haven't had any experience with Madisound drivers, but I have built
almost exactly the box you've described.  Except with 10" drivers.

>I have read a number of articles in Speaker Builder that mention Madisound
>drivers sometimes (?) tend to be way off spec (any comments)?  I have been

Again, no experience with Madisound, but suffice to say that many
manufacturer's products tend to be way off spec.  Don't trust anyone.

>unable to find any other drivers with specs that would suggest that they would
>be able to produce large amounts of subsonic (below 30Hz) output in a box
>that is as small as the one that the Madisound drivers (supposedly) require.

Weeeeeell, I don't want to admit this, but Radio Shack sells a 8 Ohm, 10"
driver that, if used in an isobaric (note the 'C') arrangement, will go to
almost exactly 20Hz, flat, in about 3.9 cubic feet.  (Nice run-on sentence,
Cal.)  Cost-effective and experimental are the key words here.

I built one.  Tested it.  Slapped it into a car, and was not that impressed.
(Typical, I'm rarely impressed with ported designs.)  However, when I stood
outside of the car with the windows down and the music playing, the system
was much more impressive.

Moral of that story (and many others as yet unvoiced):  Don't mistake
extended frequency response as the ultimate desirable goal in car subwoofer
design. (There I go on my crusade again.  Sorry.)

>I would prefer a higer efficiency driver, but it seems that most high 
>efficiency drivers tend to sacrafice low frequency extension.

I don't believe the physics of drivers makes this a requirement, but I have
not made any comparisons.  Usually I don't bother with the efficiency
calculations - power is cheap!

>Any comments/suggestions would be appreciated.  Basically, I guess, I'm
>looking for drivers which cost less than $80 which will go flat to 20HZ
>in a less than 5 cu.ft. box...

  - Just grumping with the Post-Christmas Blahs
    - Cal

-- 
--------------------------------------------------------------------------------
  - Cal Demaine                   | "You shot him in the back!"                 
    (demaine@bode.ee.ualberta.ca) |    "His back was to me!"  - El Diablo    
--------------------------------------------------------------------------------
Newsgroups: rec.audio.car
From: bstdenis@mailbox.fwrdc.rtsg.mot.com (Brian St. Denis)
Subject: subwoofers/boxes
Organization: Fort Worth Research and Development Center, Motorola, Inc.
Date: Tue, 29 Dec 1992 09:16:15 GMT


I have a 12" MTX RTP woofer (2 voice coils, their top of the line, $110)
in a 1.6 cu. ft. box, vented.  The information that came with the woofer
says it should be 1.7 cu. ft. box, but otherwise it is exact to specs.
My buddy has a Petrus Prowler PZ 124, $130, in a 2 cu. ft. box, vented
according to his instructions.  I hooked my woofer and box up to his amp.
There is no competition, the Petrus is way better, way lower, way cleaner,
even louder.  My MTX even grounds out once in a while the Prowler woofer did
not even though it was producing much more bass.

My question is can the difference in woofers make such a huge difference?
Or, could it be that my box isn't right (ie can .1 cu. inches be a problem
or could MTX have specified a bad box)?  My dealer also sold Alpine and
another type of woofer and suggested the MTX for me.

According to the response from this, I will either have to get a different
woofer, a different box or both.

Thanks in advance and any comments about MTX or other woofers are appreciated.

-Brian

Newsgroups: rec.audio.car
From: moskowit@panix.com (Len Moskowitz)
Subject: Re: Isobarik subwoofer design
Organization: Panix Public Access Internet & Unix, NYC
Date: Sat, 2 Jan 1993 23:22:16 GMT

Cal Demaine writes:

>Well, with the drivers mounted back to front, and wired IN PHASE, the volume
>of the tunnel is immaterial.

Not quite.  The spacing of the drivers in the tunnel affects the
frequency at which "isonulls" and "isopeaks" appear in the frequency
response of the system.  The dirvers are never completely identical and
you get destructive and constructive interference within the tunnel.
The shorter the tunnel, the higher the frequency at which the
interference occurs.  Ideally you want them above the frequency range of
the composite woofer.

Speaker Builder magazine had a construction article that confirmed this
rather non-intuitive effect.

-- 
Len Moskowitz
moskowit@panix.com
Newsgroups: rec.audio.car