HDTenEightyP/NetNews huggingface dataset:
From: rslau@usc.edu (Robert Lau)
Newsgroups: rec.audio.car
Subject: Re: a/d/s pq8 Center channel woes...
Date: 14 Apr 1992 23:20:37 -0700
Organization: University of Southern California, USA
NNTP-Posting-Host: tarazed.usc.edu
In-reply-to: william@pvcs.pvamu.edu's message of 11 Apr 92 01:45:00 GMT

In article <10APR199220455801@zeus.tamu.edu> william@pvcs.pvamu.edu (Devine, William Charles) writes:

      Hi....I have an a/d/s pq8 four channel amplifier and i am trying 
	    to figure out a way to use my pre-existing center channel
	    i had connected to the punch 45 this amp is replacing.
	    I don't have a manual for this amp as i bought it from 
	    someone second hand.  I was wondering if anyone knew a way
	    to connect the center channel speakers to this amps left and
	    right front channels to achieve a mono signal...

I've got the manual and the schematic in front of me...  The PQ/8
is not mono-bridgeable.  Though the schematic mentions stereo/mono
switches are shown in stereo mode, I don't see how it could work
in mono given the circuit design...
                                                             I really liked
	    the sound from my center channel (ads 320i plate) and would
	    like to continue using it..

300i's are plates, 320i's are separates

-- 
Robert Lau - Systems Programmer, Unix Systems     213-740-2866
--  University Computing Services                 Internet: rslau@usc.edu
--  University of Southern California             Bitnet:   rslau@uscvm
--  1020 W Jefferson, LA, CA  USA, 90089-0251     UUCP:     ...!uunet!usc!rslau
From: rslau@usc.edu (Robert Lau)
Newsgroups: rec.audio.car
Subject: Re: Converting AC equipment to DC/phantom power
Date: 14 Apr 1992 23:16:04 -0700
Organization: University of Southern California, USA
NNTP-Posting-Host: tarazed.usc.edu
In-reply-to: c_banks@vger.nsu.edu's message of 8 Apr 92 15:49:00 EDT

In article <1986.29e315ec@vger.nsu.edu> c_banks@vger.nsu.edu writes:

   I know many of you have seen in many of the auto/stereo mags a number of guys
   that use equipment originally designed to be operated on AC power.  What I am
   interested in is converting an EQ and a NOISEGATE to run off of DC so that I
   can usem them in my car..(The Bob Clark stuff is Way to expensive!).

Ah, but you're paying for the R&D and his next vacation ;^) You probably
know this already but...  IASCA rules states that you cannot run DC-AC
converters (aka inverters) to power AC equipment in your vehicle.

   If you have any info please send me some e-mail or post.  

   1.  Are there any books available that offer a detailed illustration of the
   needed parts or supplies?

Your university's Science & Technology library (or the equiv) should have
plenty of books on high current DC regulated power supplies if you want to
build your own.  This is not trivial material, I went through many hellish
years in EE to be able to build this stuff.  Luckily, EQ'S, noisegate's and
other signal processing equipment in general don't draw too many amps.

What you are looking for is an encapsulated DC-DC power converter.  There
are several of these on the market.  Some can take an input voltage between
9 and 36 volts DC and produce a regulated 12V at several hundred milliamps.
Others require a higher input voltage (> 19V) but can produce up to 40 amps.

   2.  Is there one kind of equipment better suited for this type of conversion
   over another?

Stuff that's microprocessor controlled is the easiest since they usually
design the entire component to run off a single DC voltage so all you'll
need to do is replace the transformer, etc with your own clean regulated DC.

   3.  Is it easier or better to use DC verses phantom power?

My understanding is that PPI's phantom power was merely a tap off their
amp's internal regulated power supply.  It could only provide a few amps
which were only meant to power low-power equipment, like a pre-amp.

-- 
Robert Lau - Systems Programmer, Unix Systems     213-740-2866
--  University Computing Services                 Internet: rslau@usc.edu
--  University of Southern California             Bitnet:   rslau@uscvm
--  1020 W Jefferson, LA, CA  USA, 90089-0251     UUCP:     ...!uunet!usc!rslau
Newsgroups: rec.audio.car
From: mxl@cbnewsg.cb.att.com (marc.a.levy)
Subject: ported box
Organization: AT&T
Distribution: na
Date: Fri, 17 Apr 1992 15:24:15 GMT

This may be a real dumb question but when a port is
calculated for a speaker box, is the result the size of the
port measured from the INSIDE of the box->in, or the OUSTIDE
of the box-> in.


In other words, if I need a 2 inch long port, do I cut a 2
inch peice of pipe? or do I cut it a 2 1/4 peice to 
compensate for the 1/4 inch wood?

Marc.


Please respond in E-Mail, save bandwidth!
  
Newsgroups: rec.audio.car
From: robb@ais.org (Robert Gonyer)
Subject: Bass Help
Organization: UMCC
Date: Thu, 16 Apr 92 01:02:45 GMT

Hi there.  I am thinking of adding a subwoofer to my system.
Right now, I have a Pioneer pullout, 6 disk changer, Sherwood
(I think it is a 1240q or something), Infinity 602 door speakers, 
Yamaha sealed box (two 8" drivers, 2 horns and a 10" or 12" passive
radiator downfiring).  The problem is, when I really get thumping,
the radiator throws so far that it hits the bottom and makes an awful         
thfffpt sound (Yes, like bill the cat).  The woofers dont seem to be
over throwing, but the radiator just hits the bottom.  Would it help
to somehow run a crossover to filter out the real lows, and send them to 
a dual voice coil MTX 10" sub?  How would I go about crossing it over 
and building the box?  Theres not much room left in my car, I have
a ''78 mustang II, and the Yamaha takes quite a bit of room.  Also, 
would it put an extra load on the amp, or make it quieter?
I consider myself an amatuer radio installer, but I have put my whole system   
in, so I'm at least a very good amatuer.  Any comments and EMAIL welcome.
Oh, btw, I have the head unit powering the infinity's (25x2).
Thanks Much!
-Robb
Newsgroups: rec.audio.car
From: brian@hopi.ugrad.ee.ufl.edu (Brian Gentry)
Subject: Re: How much do you REALLY know? :-)
Organization: UF EE Department (student)
Date: Mon, 6 Apr 92 03:13:40 GMT

In article <1992Apr3.234205.10187@ge-dab.GE.COM>, harner@test1.dab.ge.com (Keith Harner) writes:
|> In article <ktgppeINNb9j@lisa.cs.widener.edu> poulson@cs.widener.edu (Joshua R. Poulson) writes:
|> >>I've uploaded a test that sees how much you know about being an 
|> >>installer.
|> 
|> I'm on a secure site and can not directly ftp. If this test is zipped
|> can someone please email to me. Thanks
|> 
|> 
|> 
|> --
|> =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
|> |Keith Harner                                   |harner@civax.DAB.GE.COM     |
|> |General Electric Simulation and Control Systems|harner@sunny.DAB.GE.COM     |
|> =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=


Hi Keith,

I'd be glad to upload it and send it to you.  As an additional note,
I've been meaning to write to you.  It's nice to have intelligent 
(and EE knowledgable) people writing to this group.  I also appreciate the
support you give me in backing up my claims.  Do you have uudecode so
that you can recieve binaries in the mail?  Even better, do you have Z-mail?
If you're still on, write me back, or if you're on an X-windows workstation,
Xtalk to me.  My display address is:  hopi.ugrad.ee.ufl.edu:0.0

                      Talk to you later,
                       Brian L. Gentry
                (brian@sioux.ugrad.ee.ufl.edu)
From: jsmith@ug.cs.dal.ca (Jeff N Smith)
Newsgroups: rec.audio.car
Subject: Install in Ford Ranger
Date: 9 Apr 92 00:58:44 GMT
Distribution: na
Organization: Math, Stats & CS, Dalhousie University, Halifax, NS, Canada

Hello,
	I have a friend who is building a system in an 85 Ranger.  He
now has 6x9's in the lower door, 4" in dash and 8" subs behind the seats.
Each set of speakers has its own amp.  Does anyone have any suggestions or
cool ideas on how to imporve the mid bass to high end sound quality.  The
present drivers are of above average quality.  Has anyone any experience
with dash modifications (eg replace 4" with 4x6's), installation of
drivers in the vents or 6 1/2" mid bass in the doors.  He also has
a set of Recaro seats instead of the bench seat.

	Please e-mail or post any help that you can!!!

e-mail jsmith@ug.cs.dal.ca

Jeff Smith
Dalhousie University
Halifax NS
CANADA
Newsgroups: rec.audio.car
From: jreiser@scott.skidmore.edu (jason reiser)
Subject: Re: cassette adaptation needed
Organization: Skidmore College, Saratoga Springs NY
Date: Wed, 15 Apr 1992 19:06:29 GMT

goodnuff@lamp.Princeton.EDU (David W. Goodnuff) writes:
> 
> 
> Hello, forgive me if this has been discussed before.
> I just got a new car that has a pretty good radio.
> Unfortunately, it does not have a cassette deck.  Does anyone have any
> ideas of any way that I could hook up my walkman to the car speakers?
> I guess that I would have to go inside and manually attach the headphone
> output to the speakers... Thanks. (email replies welcome)
> 

This can be done without too many hastles:
        Acquire a Sony XA-7 or XA-7A (from a car stereo dealer).  This
unit is an RF modulator.  It plugs into your radio's antenna jack, and
the antenna gets pluged into it.  The RF modulator has 3 wires... one
is +12 volt, one ground and one is a trigger wire.  Whenever there is
+12 volts going into the trigger wire, the modulator will be on.  It
has a pair of RCA inputs which you can attach to the walkman with an
adaptor.  You'll need to buy a switch to control power to the XA-7(A)
and whenever it is on, one radio station will be replaced be the
signal from your walkman.  I have a feeling that I might be confusing
you, but if you have any questions about how this is accomplished,
please feel free to contact me.
 
                                - Jason Reiser
 
Sony RF modulators sell for about $40 - $60
 
  /\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\
  \                                                            /
  / Jason Reiser  Skidmore College, Saratoga Springs, NY 12866 \
  \            E-Mail at jreiser@scott.skidmore.edu            /
  /                    Or Call 518-581-7079                    \
  \                                                            /
   \/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/
                                                                

P.S.  Try to avoid double posting on the same user group.
Newsgroups: rec.audio.car
From: yystg@lims01.lerc.nasa.gov (STEVE GRAHAM)
Subject: Re: DSP for automatic Volume Control
News-Software: VAX/VMS VNEWS 1.41    
Organization: NASA Lewis Research Center
Distribution: usa
Date: 14 Apr 1992 09:05 EST  

In article <3735097@tronix.SignalPath.on.ca>, louis@tronix.SignalPath.on.ca (Louis Bertrand) writes...
>stanbach@apple.com (Francis Stanbach) writes:
>> Does anyone manufacture a car stereo with a DSP that automatically
>> changes the volume of the music depending on the noise inside the car.
>> You install a microphone near the headrest and the system plays music
>> through the speakers to adjust focus.
>> 
> 
>I've often thought about such a design, but the problem with
>adaptive filters is the compromise between speed of response
>and convergence accuracy.  Too far either way and the effects 
>are audibly unpleasant.  However, it is not inconceivable to 
>have the parameters measured and set at installation time, 
>where the adaptive convergence trade-off can be tweaked.
> 
>Besides, people bitch about a $100 equaliser, would they go
>for a $500 (my guess) DSP box?
> 
> -- Louis

Another interesting gadget - a dsp to shape the response curve to match the 
ears response at given volumes - i.e. an extended "loudness control".  This 
would allow you to adjust the volume to any level and not have to raise/
lower bass when you turn the volume up/down.  I think I would pay some $$ 
if such a beast were made.

S. Graham
Newsgroups: rec.audio.car
From: yystg@lims01.lerc.nasa.gov (STEVE GRAHAM)
Subject: Re: DSP for automatic Volume Control
News-Software: VAX/VMS VNEWS 1.41    
Organization: NASA Lewis Research Center
Distribution: usa
Date: 17 Apr 1992 09:37 EST  

In article <26858106@tronix.SignalPath.on.ca>, louis@tronix.SignalPath.on.ca (Louis Bertrand) writes...
>yystg@lims01.lerc.nasa.gov (STEVE GRAHAM) writes:
>> Another interesting gadget - a dsp to shape the response curve to match the 
>> ears response at given volumes - i.e. an extended "loudness control".  This 
>> would allow you to adjust the volume to any level and not have to raise/
>> lower bass when you turn the volume up/down.  I think I would pay some $$ 
>> if such a beast were made.
>> 
>It would be fun to experiment with, but I don't know that it would
>be well received by a wide audience.
> 
>The problem is that this gizmo would have to deal with the 
>psycho-acoustic effects of hearing.  The response changes with
>absolute volume (Fletcher-Munson curves, etc).  It is also
>susceptible to "masking" -- a strong signal at a given frequency
>will mask softer ones at adjacent frequencies.  Finally,
>a given frequency is perceived as a different pitch depending
>on the volume.
>So the shape of the absolute response is a very dynamic thing 
>and trying to track it could very well make things worse.
> 
>A, B, C, and D weighting curves are pegged to particular 
>listening levels and a simple algorithm so smoothly transition
>from one to the other would be worth playing with, but
>listener preferences would make the gizmo really chancey.
>(Then again, there's a lot of Epicentres out there...)
> 
>Ciao!
> -- Louis
>--
>Louis Bertrand   *   Lynden, Ontario, Canada   *   (416) 648-8066
>Signal Path Designs (Analog - Digital - Audio - Embedded uCs)
>louis@SignalPath.on.ca (new -- may not work yet)
>louis%tronix@maccs.dcss.mcmaster.ca (old -- still works fine)

If one wanted to get really tricky;  make the slopes user adjustable so 
they can tailor the thingy to their own ear.  I can see another full size 
DIN opening being chewed up already ;-)  Anyway, it was just a thought.  
BTW, Tony C. who works with me just dropped off the info papers on the new 
Pioneer Premier KEX-M900 car stereo with DSP and it does have a changing 
Loudness contour.  Neat!  And every other gadget around!  How does it sound
..???  The only bad thing I can see off hand is that it only comes in a 
cassette/CD changer model; I've always preferred in dash CD players :-(

S. Graham
From: sb611785@longs.LANCE.ColoState.EDU (s.burden)
Newsgroups: rec.audio.car
Subject: Shielding
Date: 16 Apr 92 16:04:25 GMT
Reply-To: sb611785@longs.LANCE.ColoState.EDU (s.burden)
Organization: Engineering College, Colorado State University


	I'm in the process of a do-it-yourself install in a 78 Sicrocco and am
woried about noise problems.  I'v seen a couple articles of installs
that use lead shielding around some of the wires.  The stuff looks like
hollow braided flexable ground strap with the wires fed through it.  Has
anyone had any experience with using this method?  If it does work, what
wires do I shield?  The low level signal wires, the power cables...? 
Thanks in advance.

                                                                    
Sean Burden
From: HAMILTON@daq.semi.harris.com (Fred Hamilton)
Newsgroups: rec.audio.car
Subject: Aftermarket speakers in an 88 Dodge Daytona
Date: 7 Apr 92 23:24:05 GMT
Article-I.D.: mlb.1992Apr7.232405.4445
Organization: Harris Semiconductor, Data Acquisition Products, Santa Clara CA
X-News-Reader: VMS NEWS 1.20


I need to replace the stock speakers in my 88 Daytona.  The door
speakers are 5 1/2", the rear are 5x7s.

1)  Has anyone succesfully (and ELEGANTLY) installed 6 1/2" speakers in
    the doors?  The Crutchfield catalog indicates that this is 
    possible...

2)  Any suggestions on good 5x7s, or can I use another size there as well?

Thanks!

-Fred
From: william@pvcs.pvamu.edu (Devine, William Charles)
Newsgroups: rec.audio.car
Subject: Cerwin Vega Enclosure?
Date: 9 Apr 92 01:37:00 GMT
Organization: Texas A&M University, Academic Computing Services
News-Software: VAX/VMS VNEWS 1.41


   Does anyone know of any exotic enclosures that can be used for
Cerwin Vega's LE-12D's?  I'm getting a pair in a week or so and would
like to do something different than their recommended vented enclosures.
they recommend a 3.0 ft^3 with a 3" port 12" long.
I would like to use around 1.5 to 2.0 ft^3 per driver since i have about
4.0 ft^3 available.  I'm thinking about a bandpass or 6th or 7th order or
something as such..  I just want something different for show.

 Does anybody have any suggestions?  I would be inputting 130 watts
per speaker (with their voice coils in parallel for a 2 ohm speaker)
anybody?
Thanx
                          Whiz Kid
--------------------------------------------------------------------------
william@pvcs.pvamu.edu    --------    devine@riphys.rice.edu
--------------------------------------------------------------------------
From: "mike frisch" <mike.frisch@canrem.com>
Newsgroups: rec.audio.car
Subject: 6s & 8s
Date: 16 Apr 92 15:29:48 EST
Reply-To: "mike frisch" <mike.frisch@canrem.com>
Distribution: rec
Organization: Canada Remote Systems


Robert Lau <rslau@usc.edu> writes...

RL> Yes, it's true, you're limited by plain & simple physics.  To get satisfyin
RL> bass, you've got to move lots of air quickly.  Unfortunately, 6" woofers
RL> generally can't do this.  What you can look for is a long excursion 6"
RL> and/or a well designed box.  But even with a good box, there's the trade-of
RL> between frequency range and sensitivity...

     I should've made myself a little more clear.  I am simply looking
for a quality 6" or 8" sub that will give me some low frequency
reproduction (ie. better than a mid-bass).  Sorry for the
misunderstanding.

     Thanks...

Mike.

+----------------------------------------------------------------+
|  Mike Frisch                  Usenet:  mike.frisch@canrem.com  |
|  Newmarket, Ontario, Canada                                    |
+----------------------------------------------------------------+

---
  OLX 2.2  Old musicians never die, they just decompose.
--
Canada Remote Systems  - Toronto, Ontario/Detroit, MI
World's Largest PCBOARD System - 416-629-7000/629-7044
Newsgroups: rec.audio.car
From: eag9s@hagar3.acc.Virginia.EDU (Edward Alexander Gianos)
Subject: Installing Portable Cd player
Reply-To: eag9s@hagar3.acc.Virginia.EDU (Edward Alexander Gianos)
Organization: University of Virginia
Distribution: uva
Date: Thu, 9 Apr 1992 19:22:13 GMT

Hey everyone...HELP!

I am installing my portable CD player in my car semi-permanently, and I
have two problems that I cannot seem to be able to solve......so I turn
to y'all for help.

First, I built a 12V-3V power supply for it.  However, it introduces
a bunch of motor noise into the line.  The unit connects by RCA leads in
the back of my Denon head unit.  The power supply I built automatically
senses when the CD is turned on, and turns the head unit control lead to
12V.  Hence, hit play, the head unit goes to CD, hit stop, back to the 
tuner.  :)  BUT, i digress, whenever the motor moves to another song, it
comes through the speakers loud and clear.  Also, there is a continual
thump thump thump thump...  that I think is the power spinning the
inertial wheel of the CD transport, or something.  My question is:
How can I eliminate these noises?  I have tried putting 50 micro-F t0
1000 micro-F caps on the 12V and 3V lines, with no luck.  The voltage
stepdown is done with a voltage regulator.  Is that chip the culprit?
C'mon you bright EEs, I need some ideas, please...

Second, I cannot seem to mount it well to eliminate the bumps and skips.
I am trying to put it (a panasonic SL-NP1) in the glove compartment, and
different permutations of foam and velcro haven't really helped.  I took
out a bunch of the foam, and now it doesn't skip on really good bass
anymore.  Ideas, anyone??  

I am really stuck here, so, ack!

Many thanks in advance....

Ed Gianos
eag9s@virginia.edu
From: dsg6397@cs.rit.edu (David S Greenberg)
Newsgroups: rec.audio.car
Subject: Going Through the file wall
Date: 16 Apr 92 15:36:36 GMT
Organization: Rochester Institute of Technology, Rochester, NY


	I was wondering if anyone knows:  Is there some trick to routing
power / ground cables from the engine compartment through the fire wall
and into the car interior. I spend a long time trying to find an existing
hole big enough to route 2 10 ga. cables through. I ended up drilling a 
hole (what a bitch!!!) and worrying about hitting something important.
	It ended up working out ok, but I figure there must be an easier
way!

						Dave
From: louis@tronix.SignalPath.on.ca (Louis Bertrand)
Subject: Re: DSP for automatic Volume Control
Newsgroups: rec.audio.car
Date: 7 Apr 92 17:15:53 GMT
Distribution: usa
Organization: Signal Path Designs

stanbach@apple.com (Francis Stanbach) writes:
> Does anyone manufacture a car stereo with a DSP that automatically
> changes the volume of the music depending on the noise inside the car.
> You install a microphone near the headrest and the system plays music
> through the speakers to adjust focus.
> 

I've often thought about such a design, but the problem with
adaptive filters is the compromise between speed of response
and convergence accuracy.  Too far either way and the effects 
are audibly unpleasant.  However, it is not inconceivable to 
have the parameters measured and set at installation time, 
where the adaptive convergence trade-off can be tweaked.

Besides, people bitch about a $100 equaliser, would they go
for a $500 (my guess) DSP box?

 -- Louis
--
Louis Bertrand   *   Lynden, Ontario, Canada   *   (416) 648-8066
Signal Path Designs (Analog - Digital - Audio - Embedded uCs)
louis@SignalPath.on.ca (new -- may not work yet)
louis%tronix@maccs.dcss.mcmaster.ca (old -- still works fine)