HDTenEightyP/NetNews huggingface dataset:
From: jch@alexander.cs.umn.edu (J.C. Hamlin)
Newsgroups: rec.audio.car
Subject: Re: Pro defeats Car Alarm - Here's how
Date: 26 Jan 93 22:32:00 GMT
Article-I.D.: news2.C1HFxE.81
Organization: University of Minnesota

In article <1993Jan23.193533@usho21.hou281.chevron.com>, hhtra@usho21.hou281.chevron.com (T.M.Haddock) writes:
|> 
|>  Several installers on the net have assured me that this is not 
|>  a NEW trick and similiar "shocking" techniques have been discussed
|>  here before.  So here it is:
|>  They removed the Jeep's left front parking light lens and bulb and
|>  stuffed the socket with aluminum foil.  They then triggered the alarm
|>  (hit it?) and when the alarm started to flash the parking lights, the
|>  "short" zapped the alarm's brain before the siren could give more than
|>  a chirp.

This works, and you're right, it isn't an old technique, except the
fact that all comercial alarms (of quality) that I know about come
with a fuse on all external outputs.  (i.e. anything that puts out a
voltage has a fuse on it.  Only one notable exception is the wire
that's almost never used, the positive door trigger).  The parking
lights output is always fused, and most of the time a relay will be
used instead of a direct connection to the lights because they draw
more current than the brain is capable of -- thus putting the trigger
and the lights on two circuits.

|>  This is suppose to work on most alarms that are not internally
|>  fused against it.

Or externally fused.  The parking lights connection wire almost always 
has an obvious fuse on it.

|>  I was told that my CODE ALARM ELITE is protected but the others are not.
|>  I was told that PRESTIGE, EXCALIBUR, and VIPER alarms are still 
|>  susceptable to this trick so, if you have these brands, be sure to 
|>  fuse all external wires and/or use relays.

These alarms all come with externally fused flashing light lines that are 
only capable of about 7 amps, which means that they'll almost always 
be connected by a professional installer by a relay to the lights.
If a *professional* installer does your installation, you can be sure that 
"tricks" like these won't work.

J.C. Hamlin
Automotive Sound & Security by Hamlin
jch@cs.umn.edu
From: keys@starchild.ncsl.nist.gov (Lawrence B. Keys)
Newsgroups: rec.audio.car
Subject: Box Builder Question?
Date: 25 Jan 93 15:06:47 GMT
Organization: National Institute of Standards & Technology


I have a question for the sub box building experts.  Will the 
response of a ported box remain unchanged if the dimensions are
changed?

To be more specific,  i have a ported box which has an volume of 
2.5 cubic ft.  It is made of 3/4"  MDF, and has a 4"x6.9" port. 
The driver is a single 12".  This box (to me) sounds great, hence
i want the retain the same sound characteristics.

I need to build a box which better conforms to my trunk, thereby 
using the space that i have better.  If i build another box using
the same driver,same port size,same building materials and give the
box the same volume, but change the dimensions...

	Will it sound the same???

I'd appreciate any help, thanks,
                                                  
                                                  
                                                  .  
                                                 /                
Larry                            __/    _______/_                 
keys@csmes.ncsl.nist.gov       /                  \               
                          _____     __     _____    \------- ===
            ----------- / ____/   /  /   /__  __/              \
         /     ___    /  / ___   /  /      / /    ____          |
        |    /      \/ /__ /  | /  /__  __/ /__ /       \      / 
        /___         \_______/ /_____/ /______/            ====OO
            \       /                           \       /         
                -                                   -
       ------------------  lb.'n till it Hz  --------------------            

Newsgroups: rec.audio.car
From: anandjr@hubcap.clemson.edu (Rajesh Anandjiwala)
Subject: HELP FOR GM-DELCO Radio/Tape Player
Organization: Clemson University, Clemson SC
Distribution: usa
Date: Fri, 22 Jan 1993 13:43:12 GMT



In my car (OLDS, 98, REGENCY) recently tape player was
not working, so I removed and found that the belt was
broken so I purchased a new belt and replaced. However, while
putting back the player in the dashboard I found that
the tape is still not working in playing mode. It does
work in FAST FORWARD and REVERSE MODE. I have a few questions as
below:

(1) As the tape is working for FF and REVERSE mode, the motor
is working, I do not know why it should not work in
PLAY mode.

(2) What is the threading arrangement of the belt, I wonder
if I have not put the belt rightly.

Could some knowledgeable help me in fixing this problem.

Many thanks for yoyr time and kind favor.

Rajesh Anandjiwala
anandjr@hubcap.clemson.edu

Newsgroups: rec.audio.car
From: fayne@tellabs.com (Jeffrey Fayne)
Subject: Re: Installation Related Item Sources
Organization: Tellabs, Lisle, IL
Distribution: usa
Date: Tue, 26 Jan 1993 13:32:45 GMT

 OOPS, sorry about the multi-posting. Looks like our new poster went
nuts (again)  :(

-- 
_____________________________________________________________________________
                                             
 F-14             |    _    |             | Jeffrey M. Fayne
   Tomcat         |  /^ ^\  |             | Tellabs, Inc.   Lisle, IL  60532
      ____________|_(  .  )_|____________ | 708-512-7726    FAX:708-852-7346
           --*/--|_| (___) |_|--\*--      | fayne@tellabs.com
              *       O O       *     fjs | #include<StdDisclaimer.h>
_____________________________________________________________________________
From: jch@alexander.cs.umn.edu (J.C. Hamlin)
Newsgroups: rec.audio.car
Subject: Re: adding caps and a center channel
Date: 26 Jan 93 21:43:22 GMT
Article-I.D.: news2.C1HDoB.M5o
Organization: University of Minnesota

In article <1jfgmlINNfi1@msuinfo.cl.msu.edu>, meiser@cps.msu.edu (Matthew E Meiser) writes:
|> I recently got a 120,000 uf 15v cap and I am wondering how I hook it up to 
|> the power input on my amp. I am also wondering if this is a big enough cap 
|> for my amp, an LA Sound Redondo 80 (4x20W into 4 ohms). 

Well, this question has been answered thouroughly already, but I'll just 
summarize:

1,000uF per watt is a good rule of thumb.  Your cap should work just fine for 
your application.  Mount in in the trunk, away from heat.  This means putting 
it after the fuse (*always* put a fuse as close to the battery as possible).
You can charge it initially in two ways, with a big resistor (probably a 
wire wound one), to keep the fuse from blowing, or just temporarily bypass 
the fuse.

|> Second, I am considering adding a center channel to improve my imaging and 
|> I need to find out how to get the mono signal without buying a lot of 
|> expensive equipment. Can I just use a Y-cable to mix the left and right 
|> output from my head unit?  Will this cause a short, or cause both stereo 
|> channels to have the same signal?

No, please don't do this.  You can split preamp signals between two 
receivers, but you can't combine two sources this way.  Examine this 
diagram for a quick explanation of why you can't do this:

        Splitting                         Combining
        Source (Low resistance)      Source 1  Source 2 (Low resistance)
           ||                             \\    //
           ||                              \\  //
          //\\                              \\//
         //  \\                              ||
     Dest.1  Dest.2 (High resistance)     Destination (High resistance)

This works as two high resistances in   Considering one source at a time,
parallel, and the power is coming from  This works as 1 low and 1 high 
the source.                             resistance wired in parallel with 
                                        power coming from that source.
                                        Which one passes all the current?
                                        The other source gets many orders 
                                        magnitude more current than the 
                                        destination.  This will overload the 
                                        input stages of one of the two sources.
                                        If you dare to test this, listen for 
                                        the volume drop after connection.

|> Thanks in advance for any help.

Welcome.  Hope I saved a source unit (or two). :-)

J.C. Hamlin
Automotive Sound & Security by Hamlin
jch@cs.umn.edu
Newsgroups: rec.audio.car
From: fayne@tellabs.com (Jeffrey Fayne)
Subject: Installation Kit Sources
Organization: Tellabs, Inc.
Distribution: usa
Date: Mon, 25 Jan 1993 13:28:55 GMT

I am looking for sources that carry car stereo installation related
items, specifically adapters to mount a shaft-style receiver in a
DIN mounting space, something on the order of what Crutchfield calls
an 'installation kit'. I'm planning on installing my system in a
'89 Taurus and would like a mounting adapter that fits the original
mounting lugs in the dash.

I'd also like to find a good source on speaker box cloth/carpeting


Any sources would be appreciated.


			Thanks,

				Jeff

BTW: i haven't called Crutchfield yet, do they sell install kits
     seperately, or are they just distributed on a system purchase only
     basis?
-- 
_____________________________________________________________________________
                                             
 F-14             |    _    |             | Jeffrey M. Fayne
   Tomcat         |  /^ ^\  |             | Tellabs, Inc.   Lisle, IL  60532
      ____________|_(  .  )_|____________ | 708-512-7726    FAX:708-852-7346
           --*/--|_| (___) |_|--\*--      | fayne@tellabs.com
              *       O O       *     fjs | #include<StdDisclaimer.h>
_____________________________________________________________________________

Newsgroups: rec.audio.car
From: kensib@cary112.its.rpi.edu (Brian C. Kensing)
Subject: wanted: full range box
Reply-To: kensib@rpi.edu
Organization: Rensselaer Polytechnic Institute, Troy, NY.
Date: Thu, 28 Jan 1993 12:31:13 GMT

	I am looking for a full range box preferably with 12's or 15's for around $200.  Send email to kensib@rpi.edu

						Thanks,
						  Brian
From: hhtra@usho72.hou281.chevron.com (T.M.Haddock)
Newsgroups: rec.audio.car
Subject: Re: Box Builder Question?
Date: 25 Jan 93 21:12:08 GMT
Organization: Chevron

In article <8239@dove.nist.gov>, keys@starchild.ncsl.nist.gov (Lawrence B. Keys) writes:
|> 
|> I have a question for the sub box building experts.  Will the 
|> response of a ported box remain unchanged if the dimensions are
|> changed?
|> 
|> To be more specific,  i have a ported box which has an volume of 
|> 2.5 cubic ft.  It is made of 3/4"  MDF, and has a 4"x6.9" port. 
|> The driver is a single 12".  This box (to me) sounds great, hence
|> i want the retain the same sound characteristics.
|> 
|> I need to build a box which better conforms to my trunk, thereby 
|> using the space that i have better.  If i build another box using
|> the same driver,same port size,same building materials and give the
|> box the same volume, but change the dimensions...
|> 
|> 	Will it sound the same???


 YES, it should.

 But don't be real surprised if it don't - it may sound better or worse.


 TRAVIS
Newsgroups: rec.audio.car
From: RYNA10@waccvm.corp.mot.com (Jay Kopycinski)
Subject: Re: Punch 30 vs. sd260
Organization: Motorola
Date: 25 Jan 1993 15:46:50 MST

------------------------- Original Article -------------------------
Also, I can pick up a brand new sd260 for $100. On the other hand I saw a
brand new Hi-Fonics Cupid for $160 (Leader Marketing show). Should I break
down and go for Cupid? (money is a desiding factor).
HELP!
Mike.S

******** WHERE CAN YOU GET A NEW SD260 FOR $100? ********

Jay


5
From: dap3257@zeus.tamu.edu (DON PERLICK)
Newsgroups: rec.audio.car
Subject: Amplifier cross-wiring?
Date: 26 Jan 1993 21:20 CST
Organization: Texas A&M University, Academic Computing Services
Distribution: world
NNTP-Posting-Host: zeus.tamu.edu
News-Software: VAX/VMS VNEWS 1.41    

	In the new _Installation News_, (Feb '93), a wiring diagram for a
system has me confused--it has two amplifiers connected!  Perhaps this is
some stereo secret that I don't know about, but I must say that _IN_ HAS
been known to make mistakes before, so I'll ask... Here's an abbreviated
wiring diagram...


             ______amp1______
            |       \        |
      (various      /   (various
       speakers)    \    Speakers)
            |       /        |
      Coil, .62mH   \     Coil, .62mH
            |_____amp2_____|
            |              |
      Coil, 2.0        Coil, 2.0
            |              |
       (more            (more
         Speakers)       Speakers)

The two amps are driven (obviously) off the same input signal.  Is that a
misprint, or something I need to know about?

Don Perlick

Newsgroups: rec.audio.car
From: jsc52962@uxa.cso.uiuc.edu (Jeffrey S. Curtis)
Subject: Re: My install--does anyone care?
Organization: University of Illinois at Urbana
Date: Fri, 22 Jan 1993 21:17:57 GMT

In article <1993Jan22.185956.1555@cas.org> mas54@cas.org () writes:
}Anyway, can I write about my system here and swap ideas with others? [...]

Please do! That's one of the reasons this group is here.

Jeff
-- 
Jeffrey S. Curtis sidewinder@uiuc.edu | "Resplendent and full again, they revel
 The Power of 37  free2207 at uiucvmd | in their role as self-appointed critics
 Sony - Phase Linear - Sanyo - Sennet | of the establishment..."
 Jensen - Polk - StreetWires - Proton |   -- INXS _Welcome to Wherever You Are_
Newsgroups: rec.audio.car
From: RYNA10@waccvm.corp.mot.com (Jay Kopycinski)
Subject: Re: Car wont start when amp connected
Organization: Motorola
Date: 25 Jan 1993 08:02:20 MST

------------------------- Original Article -------------------------
Organization: Central Michigan University
Date: Friday, 22 Jan 1993 09:15:16 EST
From: John Foster <32HNBAK@CMUVM.CSV.CMICH.EDU>
Newsgroups: rec.audio.car
Subject: Re: Car wont start when amp connected

From: ychoi@unixg.ubc.ca (Yen Choi) writes:
I have this unusual problem.

I have partially installed an amp in my trunk, and the only wires that are
connected are the power, and ground.

BUT when I try to start my car, it wont start.  at first I thought it was
because my battery was dead, so I got a jump. The car started fine, but
the next day, it would not start.  So I disconnected the power cable from
the amp and the car started just fine.

Could it be that my battery was not charged enough to start the engine (
I thought that the amp would not drain power, the remote wire was not
connected)

 Any explanations would be really appreciated.

IS THE AMP CONNECTED DIRECTLY TO THE CAR BATTERY ?
Jay
From: bdamiani@violet.ccit.arizona.edu
Newsgroups: rec.audio.car
Subject: Re: Leader Marketing Co.
Date: 21 Jan 93 23:22:29 GMT
Distribution: world,local
Nntp-Posting-User: bdamiani

In article <C14twv.IFJ@news.cso.uiuc.edu>, jsc52962@uxa.cso.uiuc.edu (Jeffrey S. Curtis) writes:
> In article <19JAN93190458@tiamat.hacks.arizona.edu> bdamiani.ccit.arizona.edu writes:
> }Please be careful about what you buy at places like this.  Your best bet is to
> }only buy BRAND NAME stuff that you have heard of before.  Stay away from the
> }generic stuff tha sounds good or you could get screwed.  I did. :)
> 
> Please, please, please, *please* tell me you didn't buy the "American
> Hi-Fi" (or whatever brand) "100 watt, 5-way 6x9 speakers" for $4 each!
> 
> Jeff


No, it was not quite that bad.  I bought a generic amp that said 400 watts but
was more like 50 and a pair of 15" woofers that just plain did not last.

:(
Newsgroups: rec.audio.car
From: jsc52962@uxa.cso.uiuc.edu (Jeffrey S. Curtis)
Subject: Re: adding caps and a center channel
Organization: University of Illinois at Urbana
Date: Thu, 21 Jan 1993 06:32:09 GMT

In article <20JAN199316312680@rosie.uh.edu> st1q9@rosie.uh.edu (Devine, Della M) writes:
}The reason they recommended a resistor on the positive side was to
}limit the current the cap pulled the instant it was powered on.
}I didn't think it was a good idea until i first installed my
}caps on my system. (just 240KmF for 220 watts).  I just hooked up the
                          ^^^^^^

Well, there's your problem - you were using a 240 farad capacitor.  Where
was it mounted - the trunk, or the roof?  ;-)

(I assume you meant 240KuF, or 240,000uF)

}positive to the terminal, screwed it in, then hooked up the negative
}the instant i touched the ground to the cap my fuses blew..
}mind you this was just the first one and it blew two 30amp fuses for this
}amp. (it uses two 10guage wires with 30amps fused each for some reason..it's
}an old , 3 years, linear power 2202).
}this blew minmy mind!!!  60 amps!!!  te next one oi chatrged up with
}a 10 ohm 10 watt resistor inline and it waarmed the resistor up but didn't
}pul but about 1 to 12..that is 1.2 amps. (my delete dont work right now!)
}anyway, the resistor saved me the 3 dollars for two new fuses again....

Ok, this seems like a fair solution to prevent the caps from rapidly
charging and blowing your fuses.  The problem, though, is that it also
prevents the cap from rapidly discharging, which is the reason it's
there in the first place.  So what do you do? The first thing that
comes to my mind is to have a switchable circuit that bypasses the
resistor after the initial second or so that the cap will be charging.
This should probably work out since the cap probably won't ever discharge
to the point of needing to draw massive amounts of current fast (on the
order of magnitude of when it first powers up).

If my thinking is completely off-base, I apologize - it's kind of late.

Jeff
-- 
Jeffrey S. Curtis sidewinder@uiuc.edu | "Resplendent and full again, they revel
 The Power of 37  free2207 at uiucvmd | in their role as self-appointed critics
 Sony - Phase Linear - Sanyo - Sennet | of the establishment..."
 Jensen - Polk - StreetWires - Proton |   -- INXS _Welcome to Wherever You Are_
From: bbs.nuklhed@gilligan.tsoft.net (Allen Caday)
Newsgroups: rec.audio.car
Subject: car alarms? recommendations?
Date: 26 Jan 93 08:18:58 GMT
Organization: The TSoft BBS and Public Access Unix, +1 415 969 8238

As I'm relatively new at the audio business and alarms, if this
message sounds like it doesn't make any sense, it probably doesn't.
:)

I have just upgraded my factory stereo after having the car for
three years (hey, so I'm a bit slow, so sue me).  Well, I need
some recommendations for a good car alarm in the $200-$300 price
range.

Thank you...for your support.

BTW, now that I got a decent unit, is it possible to upgrade my
pitiful dash speakers to something pretty good.  (It's in an '86
Toyota MR2).  Is it possible to get a good speaker set-up in that
car?  Suggestions?  I've lived in the dark ages for 3 years, and 
now I've heard the light and I want more. Heh.

--
Allen Caday (bbs.nuklhed@gilligan.tsoft.net)
From: walkerr@teak.WPI.EDU (Robert A Walker)
Newsgroups: rec.audio.car
Subject: crossover point?
Date: 26 Jan 1993 02:29:46 GMT
Organization: Worcester Polytechnic Institute
NNTP-Posting-Host: teak.wpi.edu

	I'm setting up a system in my bronco, I've got two 12 inch subs in
the way back and a pair of 2-way 6X9s in the wall about a foot behind the
front seats.  Now don't laugh, but i have two RadioShack amplifiers.  I'm
broke, and i got them on sale plus a 10% discount from a friend.  I also
bought the subs used from a friend.  Anyways, one of hte amps is the
120 watt sub amp which i have crossed over at 100 hz using the little
switch on the amp, the other is the 80X80 powering the 6X9s, i know that
is messed up, but i can't afford an electronic crossover.  I have 220 uF 
caps on the 6X9s which crosses them over a little less than 200 hz.  Is this
a reasonable crossover point, i had it lower around 90 but the speakers 
couldn't handle it and complained immensly.  Should i cross the subs over at
200 hz also when i get up some money to purchase a crossover, or should i
put my money in a pair of speakers to put in the front doors?  THanx for 
any help and please don't laugh :)

Newsgroups: rec.audio.car
From: klm41661@uxa.cso.uiuc.edu (  Kevin Molander)
Subject: Re: crossover point?
Organization: University of Illinois at Urbana
Date: Thu, 28 Jan 1993 01:16:48 GMT

I would definitely agree with Jeff's response.  I recently set up a 
system with 4 6.5 coaxials and two 12" subs.  We crossed the 6.5s at
200hz with 6dB capacitors.  We were also going to do the same with 
inductors for the subs, but they sounded far better with the amp's built-
in 70hz 12dB/octave low-pass filter.  The "hole" was not noticeable and
the entire system sounded much cleaner, with no loss of mid-bass.

Kevin Molander			klm41661@uxa.cso.uiuc.edu    

Newsgroups: rec.audio.car
Newsgroups: rec.audio.car

Ken Blair writes:
>Kirk Lindstrom writes...
>[...]
>
>>> 5) When it comes to power handling, is more better?
>>>
>>No, for speakers.  Yes for amps. 
>
>[...]
>
>I don't think that is true at all.  It all depends on your requirements and
>applications.  You can't make it that simple.
>
>Mr. Weather <> aka Ken Blair <> rkb6116@zeus.tamu.edu <> Aggieland USA
>----------
OK, I have some 150 WPC speakers I'll trade you for some nice 50 WPC
MB Quarts.  If you have good, clean amps you can run your speakers
as loud as you can take it.  I've put 125 Watt peaks into BA 6x9s in a box
and they didn't break-up or distort badly.  Of course they were only
drawing 1-10 WPC average.  Any louder and the amp would start to clip
on the louder passages (Marantz 1978 vitange amp/receiver).

If your amp says it will put out 30WPC RMS, it doesn't mean you can
listen to music with it at that level as the peaks will clip the amp and
fry your speakers.  Hence the power rating is useless unless you want to
listen to distortion.

Kirk out
Newsgroups: rec.audio.car
From: jch@alexander.cs.umn.edu (J.C. Hamlin)
Subject: Re: Quick Question about Class A amps...
Organization: University of Minnesota
Date: Tue, 26 Jan 1993 21:15:18 GMT

Howdy car audio fans, consumers, and customers!  It's me, and I'm back! :-)


In article <93018.102501DMW122@psuvm.psu.edu>, Duane Whitlock 
<DMW122@psuvm.psu.edu> writes:
|> Hi,
|>      Quick question.  I have a Denon amplifier and according to the specs, 
|> it is a Class A amplifier.  I'm not trying to start another larger heap 
|> about whether a car amplifier can be a Class A amp or not.

Well, you're looking at a long shot here.  As you've stated, it is very rare
(but not impossible) for a car amp to be class A.  Actually, it is considered 
undesirable to have a class A amp in your car because it will create a severe
heat dissapation problem.  Class A amps are always passing a lot of current 
and always generating a lot of heat; when compared to a class AB amp which 
is a demand based power system and passes only as much current as it needs, 
the class AB will run much cooler.  Remember that power loss is proportional 
to the current squared (P = I^2 * R = I^2 / V) and when the current draw 
goes up, so does the heat generated.

Because the life of electronic components is inversely related to the 
temperature they are operated at, most car amplifier manufacturers feel that 
longevity is more important than the subtle sonic differences that exist 
between a class A amp and a class AB (if you can even detect them).  However,
since there is a general public opinion that class A amps are "superior" 
to class AB manufacturers will often label their amps class A to attract 
customers.  The manufacturers justify their "class A" label because the 
amplifier has some properties of a class A amp, but also some of a class AB, 
making it some sort of hybrid that could be called either.  However, if you 
classify "A" and "AB" as I have done above, almost all car amplifiers 
will be considered class AB.

I talked to a representative from Denon, who claimed that some of their 
car amplifiers are class A, but refused to comment about any particulars of 
how or why they are classified that way.

J.C. Hamlin
Automotive Sound & Security by Hamlin
jch@cs.umn.edu