Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!caen!hellgate.utah.edu!dog.ee.lbl.gov!ucbvax!shiva.Berkeley.EDU!bks
From: bks@shiva.Berkeley.EDU (Brian K. Shiratsuki)
Newsgroups: sci.electronics
Subject: Re: L-R output for center front car speaker
Message-ID: <41636@ucbvax.BERKELEY.EDU>
Date: 8 Apr 91 19:40:29 GMT
References: <1486@lehi3b15.csee.Lehigh.EDU>
Sender: nobody@ucbvax.BERKELEY.EDU
Reply-To: bks@shiva.Berkeley.EDU (Brian K. Shiratsuki)
Distribution: na
Organization: University of California at Berkeley
Lines: 31

In article <1486@lehi3b15.csee.Lehigh.EDU> tbrown@lehi3b15.csee.Lehigh.EDU (Thomas Brown [901015]) writes:
>What is the best way to obtain a difference output (L-R) from separate
>L and R outputs (about 12W/channel) without damaging the power amplifier
>in the radio?  If this is a problem, a sum output (L+R) would also be
>acceptable, but the difference output would enhance the overall stereo
>effect in the system.

the factory stereo in my car came with one center speaker in the front,
and two on either side in the rear.  i added two speakers on either
side in the front, and run them with an outboard power amplifier.  the
center front speaker is disconnected (none of the factory speakers were
Particularly Good), but i run the rear speakers in series and out of
phase with the difference signal from the amplifier built into the
radio.

the way to do this is to disconnect the - sides of the two rear speakers
from the radio, and connect them together.  if the radio works with a common
ground, you hear interesting ambience stuff from the rear.  the fader
on the radio works as an attenuator, but i like the effect full-blast.
the radio has not been damaged at all by this, and i believe it would
even be safe to run the rear speakers from the outboard amp.  but then
the inboard amp wouldn't have anything to do and i wouldn't have a built-in
attenuator.

i don't think that i would want the ambience stuff coming from the center
middle.

the idea for the arrangement came from the dyna company, maybe even from
hafler.

					brian