HDTenEightyP/NetNews huggingface dataset:
From: mxl@cbnewsg.cb.att.com (marc.a.levy)
Newsgroups: rec.audio.car
Subject: Re: How to reduce alternator whine
Date: 23 Nov 92 20:45:51 GMT
Organization: AT&T

In article <1992Nov23.165447.19566@panix.com> dans@panix.com (Dan Simoes) writes:
>
>Could someone please post a description of how to reduce or eliminate 
>alternator whine coming through an amp using capacitors?
>
>I asked this once before, but didn't understand the replies.
>I rewired the amp using RCA shielded, gold-plug wires which run on
>the side of the car opposite the power wires (amp is trunk-mounted).
>The amp's power and ground are run directly to the battery, and the 
>trigger wire comes from the head unit.
>

This is a FAQ, and if it's not, it should be! (I have not seen
the FAQ in a while)

Anyway, my experience with Engine noise is that you dont NEED
to install any sort of filter network, or capcitor.  Although
this type of fix will work some of the time, it is almost
never nessasary.

Most alternator whine problems are due to a ground loop.  You
do not need to ground the amp directly to the battery, infact
this is a waste of time, and wire, and could actualy hurt the
quality of your system (Depending on the grade of wire used)
It is improtant that all components be grounded at the same
point on the chasis.

I have found many times that engine noise is almost always
either a installation problem, or defective equipment (Or
crappy equipment)         

I would first isolate all of the components to find out  what
component the noise is getting in.  The eaisest way to do this
is disconnect the audio input leads to the amplifier, and see
if the noise goes away, if it does, the problem is most likley
the head unit, so you may want to dissconnect the antenna
lead, and see if it goes away (The head unit is also grounded
to the chassis through the antenna cable)  The noise will
almost always go away at this point if you have only a head
unit and amplifier, but if the amp still makes noise even when
the audio inputs are not connected, the amp is either not
installed correctly, or is a hunk of junk.

If it is a hunk of junk, a Radio Shack High Current noise
filter MAY do the trick, but it is a $15 gamble.

Here is a example: I installed a system in my friends CRX this
weekend, the system was a CD player, 3 amplifiers, a
crossover, and 4 speakers+2 subwoofers.  After about a hour or
so working at getting the noise gone, I swapped out the
crossover.  The crossover was defective, and was causing a
ground loop.  We went out, and picked up a new one.. Now, with
a 560W system, there is no noise whatsoever.

Good luck.

Marc
Newsgroups: rec.audio.car
Subject: RE: CAR ALARMS
From: aleung@uwpg02.uwinnipeg.ca
Date: 21 NOV 92 21:01:29 CST
Organization: University of Winnipeg

I got my alarm system for two years. I just got one false alram so far.
I just using the cheapest ALPINE 8030A.
From: trw@spl1.spl.loral.com (Tim R Witort)
Newsgroups: rec.audio.car
Subject: Sony Changer Compatibility
Date: 19 Nov 92 23:21:52 GMT
Organization: Loral Software Productivity Laboratory

In article <CMM.0.90.4.722179090.clane@magnus.acs.ohio-state.edu>, clane@magnus.acs.ohio-state.edu (bored-out-of-my-skull) writes:
|> 
|> 
|> So Sony isnt making the changers that will work with the XR series anymore?
|> 
|> I was just going to ask that,  [expletive]!  I suppose when I graduate and get a
|> real car i will have to buy another stereo...........

   Good point.  Are the new "U" serires Sony CD changers 
compatible with their controllers that control the older
"X" series?  I wouldn't expect all of the nifty new features
of the "U" series to work, but would the standard old 
features work?  I have the Sony car DAT deck which can
control an "X" series CD changer - but will it control the
new "U" series?

-- Tim
Organization: Penn State University
Date: Mon, 23 Nov 1992 11:58:18 EST
From: Duane Whitlock <DMW122@psuvm.psu.edu>
Newsgroups: rec.audio.car
Subject: STUPID but SAFE?

Hi all,
     I'm about to take my friends home from college and I'll be driving.  I've
got a fairly expensive radio and amp with speakers, 6x9's being the largest.
My question is that my amp has a subwoofer output.  Quite a powerful one, I thi
nk.  Would it be safe to hook an 8 ohm speaker to this amplifier?  What I'm ref
erring to is my home stereo speaker.  It's 270 max at 8 ohm. It's a SonySS-U511
 or something like-definately not top of the line, but it has 2 12" woofers.  I
f I put it securely in my trunk, will it damage the speaker?  I'm not going to
do this, unless someone responds to me and tells me its safe.  I don't want to
ruin my home speaker in ANY way though, because .... well, I just don't want to
.  If anybody could e-mail the consequences of my putting the home speaker in m
y trunk, please do so by Tuesday 11/23 afternoon, because I'm leaving then.
     I realize that this is stupid so I'd appreciate refraining from sending me
 mail telling me so.  Also, this is purely temporarily.  I'm happy with my syst
em, but I have that gut-level desire to impress them with some deep bass.  Any
responses are greatly appreciated.

Rec.audio.car amateur TEMPORARILY in "show-off" mode to his friends...
DMW122@psuvm.psu.edu
(Duane Whitlock)
Newsgroups: rec.audio.car
From: chenh@neptune.ecs.csus.edu (H. Philip Chen)
Subject: Uni-Link, Re: Sony Changer Compatibility
Organization: California State University, Sacramento
Date: Mon, 23 Nov 92 01:15:14 GMT

jeh@cmkrnl.com writes:
:: [...]
: [...]
:The old "X" series have an cable with about a dozen pins in the connector.  I
:got a look at the connector for the U-series changer (a Dow Stereo sales droid 
:tried to sell me one to go with my XR-7280).  The connector looks similar from
:a distance, but close up it appeared that there were just two (2) pins!  
:
:I'm not sure how they're multiplexing two channels of audio plus control
:signals to and from the changer PLUS power on two wires (plus the shield)... I
:suppose that using "phantom power" techniques and putting the control signals
:on carriers above the audio band would do it.  Heck, the audio could be riding
:on a carrier for that matter -- Sony has chips to encode stereo audio on a 200
:kHz or so carrier and to decode it back again; these are used in their infrared
:headphones.  They could be doing the same thing here, just eliminating the IR
:part. 
:
:However it works, it's surely a different signalling scheme than the X series
:uses, so forget about hooking one to the other with a simple cable adapter. 
:
:Of course I could be wrong.  Don't rush out and buy a new head unit on my 
:advice alone!  I suppose the best thing to do would be to call Sony and ask
:them if an adapter is available.  Let us know what you find out. 
:

Sounds like wrong information to me.

The Unilink connector has eight (8) pins!  And then there's another 
one - the shield (may be the ground/reference).

The connector will only go in one way, ie. won't fit if one tries to 
plug it in upside down.  

Not only that, there are two separate audio outputs (RCA type). 



-phil

Newsgroups: rec.audio.car
From: brian@crow.eel.ufl.edu (Brian Gentry)
Subject: Re: capacitors
Organization: UF EE Department (student)
Date: Sun, 15 Nov 92 22:53:41 GMT

In article <gilchr.721474539@ee.ualberta.ca>, gilchr@ee.ualberta.ca (Andrew Gilchrist) writes:

[...]
|> Passive crossovers aren't good for more than 6dB/octave.  If you
|> go past that, the rolloff at the -3dB point gets flatter and flatter.

Do you mean that the response at the -3 dB point is not really -3 dB?
Or do you mean that the instantaneous slope at the -3dB point gets
closer to 0?  Or is it something else?

Look at the passive crossover circuits used in high-end dynamic loudspeaker
systems.  Most of them are 12 or 18 dB/oct in at least one section.  These
loudspeakers sound very good.  Are you suggesting that the only loudspeakers
that sound good are either actively crossed over or use 6dB/oct slopes?

6dB/oct slopes CAN produce a minimum phase output, but that is perhaps their
only benifit.  Higher slopes protect your drivers more and minimize the 
interaction of the drivers outside of the crossover region.  Both of these
are desirable characteristics.  In addition, it is not possible to achieve
some effects without using higher order slopes.  For example, the D'Appolito
configuration requires an ACOUSTICAL 18dB/oct slope on both the tweeter
and midrange.  You'd be hard pressed to find a tweeter and a mid that had
12 dB/oct slopes without crossovers.  These slopes would have to be located
exactly at the crossover frequency.  This is the only way you could use 
first order crossovers and still get the excellent polar pattern offered
by the D'Appolito configuration.  Otherwise you have to use 12 or 18 dB/oct
crossovers to satisfy the slope condition of the D'Appolito configuration.

[...]
|> 
|> Andrew

			Brian L. Gentry
		   (brian@sioux.eel.ufl.edu)
From: st1q9@rosie.uh.edu (Devine, Della M)
Newsgroups: rec.audio.car
Subject: Re: DREAM SYSTEM...
Date: 23 Nov 1992 00:23 CST
Organization: University of Houston
Distribution: world
NNTP-Posting-Host: rosie.uh.edu
News-Software: VAX/VMS VNEWS 1.41    

In article <1992Nov21.062540.5066@ra.oc.com>, jdavis@wizard.etsu.edu (Jason Davis) writes...
>About a year ago someone wrote about something similar to this that supposidly
>existed, I believe on the east coast.  The system described included 20 of the
>EV (Electro Voice) 30 inch subs running on Orion Power.  The enclosure w/ subs
>was located in the trailor which was 'booted' to the tractor.  Has anyone else
>ever heard anything about this?  This was in a letter included in CA&E.  I
>don't recall the date, it could have been a couple of years.  Verification
>anyone?
>							-Jason Lee Davis  73's

   I remember that too!!!   It was in a letter response about that
 1 million watt cadillac that everybody wrote letters to CA&E to laugh at.
The guy said that he's running 20,000 watts on 20 EV 30" subs and another
5,000 watts on his woofers/midbass/midrange/and tweeters.  All orions.
I just assumed he was full of shit as was the cadillac. And i guess i was
right cuz we would've DEFINITELY heard something about it if it actually
did come out!

   On an aside, i remember the New York Philharmonic Orchestra (i think that's
the name) was using 90 of the Linear 5002's for their mobile orchestral
system for outside performances and such.  45,000 WATTS!!!!  I about
died...  Bet it's nice to eh?  That was announced in a CA&E and
Car Stereo Review Mag about a year ago.  So i assumed it was viable
information.

                              William C. Devine, II
reply to: Devine@pvhep.pvamu.edu
From: keys@starchild.ncsl.nist.gov (Lawrence B. Keys)
Newsgroups: rec.audio.car
Subject: Decreasing Volume in Sub-box
Date: 16 Nov 92 17:28:56 GMT
Organization: National Institute of Standards & Technology


Last week i took off from work, and during that time i decided to 
build a subbox for my JL Audio 12W5 subwoofer.  Based on the specs
that i got from the dealer the box should have an interior volume of
2.5 and a port of 4" inside diameter @ 6.9" length, for optimum
performance.  Well as it turns out the interior volume of the box that i
is actually 3.1 cubic feet.

After i built the box, and realized my error, i took my box to the dealer
to listen to in his sound room.  I did this because, i don't have an amp
for my sub, and also because i don't yet have a crossover.

In the sound room the box sounded great to me, although, i continue to
wonder if the box were more to spec., would it perform even better.  At
higher volumes the cone seemed to flop around more.


Anyway, my question is, how can i reduce box volume without building
a new box, and without making the box any heavier?  Would blocks of 
foam of the proper volume do the trick?`

any and all suggestion welcomed.

Thanks,
                                                   .              
                                                 /                
Larry                            __/    ______ /                  
keys@csmes.ncsl.nist.gov       /                \                 
                         _ _ _      __      _____  \------- ===   
            ---------- /  __ /    /  /    /__  __/            \   
         /            /  / ____  /  /       / /                |  
        |            / /___/  / /  /__   __/ /__              /   
        /_____       \______/  /_____ / /______/        --- ////   
             \_____           2 liter 16v       \_______/         
                                                                              

                            lb.'n till it Hz
                        

Newsgroups: rec.audio.car
From: gilchr@ee.ualberta.ca (Andrew Gilchrist)
Subject: Re: Capacitors, etc... CALMLY
Organization: University Of Alberta, Edmonton Canada
Date: Mon, 23 Nov 1992 10:59:31 GMT

brian@hopi.eel.ufl.edu (Brian Gentry) writes:

>I thought that the major reason for using these caps was because of the
>poor transient capability of the car battery.  I know that a battery 
>can put out a lot of current for a short time (i.e. starting the car) but
>I thought it had bad performance for very fast transients.

No... I don't think anyone said that.  Let me take another stab at this.
The charging voltage (say 13.8, just for fun) is higher than the
battery voltage.  If you are drawing current from the battery, this implies
that your load voltage is around 12 Volts... thus, your car is failing to
keep the load voltage regulated to an acceptable level.  If your
load voltage is fluctuating 13%, as in this example, it is possible that
it will affect amplifier performance.  SO, the purpose of the
bypass/"stiffening" capacitors, is to improve the regulation of your
charging system... particularly with transient current demand.
(it would surprise me to discover that your car's alternator had a very
low AC impedance... however, since my specialty is not car charging
systems, I will refrain from making bold assertions in this area)


>be mistaken.  In any case, the highest frequency we should be worried about
>is 22.05kHz as this is the highest frequency reproducable by a CD player.

No. Since the amplifier is a non-linear load, it's tough to predict the
max. frequency to expect... 

>I have seen a comparison of capacitance vs.
>frequency for a big electrolytic, before and after being bypassed with a

This confuses me.  Please describe the testing procedure.

>I think that especially for this application (stiffening capacitors) the use
>of small "bypass" caps is really overkill.  I think that you would not be
>able to tell the difference audibly and would probably be hard pressed to
>measure it.
Possibly.

Andrew
From: mohrt@cse.unl.edu (Monte Ohrt)
Newsgroups: rec.audio.car
Subject: FOR SALE
Date: 17 Nov 1992 22:21:30 GMT
Organization: University of Nebraska--Lincoln	
Distribution: usa
NNTP-Posting-Host: cse.unl.edu

I have the following items for sale:    

SONY XE-90 Mk II Equalizer:

9-band graphic eq. 
Line-level in-out  (passive)
fader control
Listening pos. control
.005% THD
built in sub-crossover

This unit is brand new...  Warranty good through July '93
Comes with manuals, box, mounting brackets, the works.
I paid $199.99 for it.. asking $110 o.b.o.

---------------------------------------------------------

LA sound 3-way crossover:

modes: 2-way/3-way/2-way+sub
Slope: 12 db octave
Multiple input cap.
Adjustable crossover frequencies.
	Low: 80hz/125Hz/250Hz
	High: 2.3khz/3.5khz/5khz
Adj. output levels
S/N ratio: 115 db

This is also like new in the box.  asking $110 o.b.o.

----------------------------------------------------------

Pyle 2-way door speakers:

5 1/4 speakers.  (1 pair)  used for about a month.
give me your best offer on these.

----------------------------------------------------------

that's it!  

mohrt@cse.unl.edu

--
     *        .        .          * .    .        . .        .        *
Monte Ohrt      .    *       ________________ _      .    ____      *
U. of Nebraska at Lin.   .  <-_______________|*) .  ___==/    \==___
Internet: mohrt@cse.unl.edu  ~.      *   | |  ~  --==================--
Xref: sparky rec.audio.car:4938 alt.locksmithing:2025 alt.tasteless:12685
From: dunster@sdsu.edu (mark dunster)
Newsgroups: rec.audio.car,alt.locksmithing,alt.tasteless
Subject: Nabbing a car thief (was: car alarms)
Date: 18 Nov 92 22:36:16 GMT
Organization: sdsu
NNTP-Posting-Host: mathfp14.sdsu.edu

In article <kmr4.257.722096419@po.CWRU.edu>, kmr4@po.CWRU.edu 
(Keith M. Ryan) writes:

> My first alarm was a Crime Stopper Pager (4901?), for $110 from 
> crutchfield.

                        <technical details deleted> 

>  	It saved my system on three occasions, twice they had cut the ground 
> strap, and foolishly thought it was disabled. One time, the thief ( a local 
> punk who knew I had a sound system ) thought this disabled the system. 

 
> 	Late one night, ~ 3 am, my pager went off, and I quickly put my 
> shoes on, called 911 then grabbed the family 12 ga. I quietly went out the 
> back door, and came around. He was lying on the seat, trying to work the 
> Alpine head unit out. I shone my maglight on him, and told him to freeze. I 
> think he lost his bowels. :-) Doing hard time, doing hard time. They got him 
> on grand theft auto.

Presumably, then, you held this s.o.b. captive whilst waiting for the cops
to arrive. I've often wondered about someone actually doing this, and now
at long last I've discovered a real person who has. I'm intrigued:

How did the cops react when they arrived on the scene? Did they order you 
to drop your weapon? (after all, they don't know at first sight who's the 
good guy).

What did they think of you holding a thief at gunpoint? Did they commend
you, or were they a little pissed off (their recommendation is to never
confront a thief if possible)

Is it actually legal to make a "citizen's arrest" of a car thief with 
a gun?

How did you hold the thief? Did you make him stay lying on the floor, with
his hands behind his head?

If he had decided to make a run for it, you presumably wouldn't want to 
shoot him in the back (manslaughter I would think). My guess is that most 
thieves would just make a run for it, and not give up quietly.

Anyway, good job! Nail those son-of-a-bitch bastards! 
Cheers, mark dunster
From: mary@Cayman.COM (Mary Malmros)
Newsgroups: rec.audio.car
Subject: Re: CAR ALARMS
Date: 19 Nov 92 15:48:49 GMT
Organization: Cayman Systems Inc., Cambridge, MA
In-reply-to: rob.runkle@cccbbs.UUCP's message of 16 Nov 92 22:10:00 GMT


In article <3653.110.uupcb@cccbbs.UUCP> rob.runkle@cccbbs.UUCP (Rob Runkle) writes:

   -> Maybe I am alone in this statement.
   -> I would almost love to see some jerk get his car stolen
   -> when I think of all of the false alarms I have to deal with!!

   I hope you are alone.  Bitch and Moan......Awww!  I don't know about you
   but I have alot to protect in my car and if my alarm goes off once or
   twice a year........tough!  I have 4 different sensors in my car and it
   RARELY ever goes off.  If it does....it is because some ass bumped it or
   something.  So....as you say it.....DEAL WITH IT!
		   Thanx,  Rob Runkle
   P.S.  Lets see if we can make everthing perfectly silent for this guy.


You completely miss the point.  One comedian referred to audible car
alarms as "urban crickets", and that's exactly what they are.  NOBODY
PAYS ANY ATTENTION TO THEM!  They are useless!  When an alarm goes
off in my street late at night, do you think people come running
out to see if it's their car being took off?  No, they roll over and
go back to sleep.  

I don't see any point in buying an audible alarm.  There are exactly
two things that I would do: the Club, and lo-jack.  
--
------------------------------------------------------------------------------
 Mary Malmros     | Cayman Systems Inc, 26 Landsdowne St, Cambridge, MA 02139
 mary@cayman.com  | Phone 617-494-1999  Fax 617-494-5167  AppleLink CAYMAN.TECH
From: rob.runkle@cccbbs.UUCP (Rob Runkle) 
Newsgroups: rec.audio.car
Subject: RE: CAR ALARMS
Date: 20 Nov 92 01:11:00 GMT
Distribution: world
Organization: Cincinnati Computer Connection BBS - Cincinnati, OH - 513-752-8248
Reply-To: rob.runkle@cccbbs.UUCP (Rob Runkle) 

Mary,
-> You completely miss the point.  One comedian referred to audible car
-> alarms as "urban crickets", and that's exactly what they are. NOBODY
-> PAYS ANY ATTENTION TO THEM!  They are useless!  When an alarm goes
-> off in my street late at night, do you think people come running out
-> to see if it's their car being took off?  No, they roll over and go
-> back to sleep.

        That is totally untrue!!!  Every time I turn my alarm off or on
in a parking lot I am amazed that EVERYONE looks.  It is a little
embarassing when you accidentally scare someone who is walking next to
it.  The point is....people do notice alarms and they are not ignored.
Now I agree that one may hear an alarm outside and just ignore it...but
normally a thief will not take that chance.  There is much more prey out
there.  Prey that won't bite back and gives LESS chance of the breakin
getting noticed.  That is the total purpose of an alarm.  Yes!  It is
nice that MAYBE someone would notice but the main reason is to deter the
thief and give him a reason to go on to the next car.  Maybe you should
quit getting your facts off of the comedy channel.
        Thanxs  Rob Runkle
P.S.  You bet I will get up if I hear my alarm go off.  Damn Straight!
      It helps that my car is usually parked outside my window though.
P.S.S.  The only time that I have had a car broken into was the one time
        that I did not have the alarm in.  It was being serviced.  My
        bad habit of leaving the radar detector on the dash was quite
        the cause...but I left it there many times before.  Others cars
        were broken into in my lot but never mine.  My area has a
        pretty high rate of this kind of crime.