Problems W/ Rear Amp Hookup - 5th Gen - Honda Prelude Forum

pIOUs · 05-11-2001, 11:11 PM

Thought I Had it all figured out. I tapped in to the stock rear amp with RCA cables for the signal:

Helm reference 23-156
connectors B7&B17 (BLU/YEL&GRY/WHT)for the left channel
connectors B8&B18 (RED/YEL&BRN/WHT)for the right channel.

After connecting them to the amp I started getting signal degradation until it became a whinning popping sound that was independent of stereo volume (Whole system stock; this project is to add rear speakers and amp for those speakers only).
I check for ground line to body ground = zero
pos-neg=~12vDC
the amp has no problem with an external signal source (i.e. home CD player)and vice versa I can use the audio signal from the car and feed it into a mixer and it comes through pretty clear. Problem with the tests is that they use an independent ground

When the car audio cables are fed into the amp with only the ground plugged into it (No BAT or ACC lead) the noise starts up in the front speakers.

Also, there is 6vDC coming through the nuetral side of the audio cables and this must be why it starts up when I ground the amp.

Has anybody tried this before? I looked and didn't find anything. (see below) There shouldn't be a voltage coming through the audio cable except about a few millivolts right? PS. I soldered the leads to the actual tabs on the back of the stock amp connector so as not to splice the wire harness...looks clean, but doesn't work

lastly I found a dead link on NTPOG's web site refering to a prelude audio system bible and couldn't locate it on the web.

Thanks guys

Correction found Joon525's Post, but more confused

:
He seems to be using these same wires to plug straight into aftermarket speakers??? these wires show to be coming from the head unit wire harness...is this signal already amplified from the head-unit? hmmm AFBS...is this reeally an amplifiier in the back anyways? if not then why is the impedence different for the back speakers?

Summary of Questions:
1) Are the signals I'm referencing above amplified or line level?
2) Is that black box even an amplifier?
3) If I want to tap in to the audio signal in the back, will I have to get one of those signal reducers that converts to RCA jacks?
4) why is this causing noise feedback in the audio system? (bonus Question

).

Unwind this enigma!

Ferrd · 05-12-2001, 10:07 AM

I was able to run an amp just using the wires that go into the afbs amp in the trunk, with out rca cables. I read this web site, and it gave me all the info I needed to do this. Before reading the web site, I had run the amp from the wires that run the rear deck speakers. It sounded AWEFUL, and had horrible feedback. Once I changed the wiring, and ran the wires from before the afbs amp, it sounded MUCH better. here's the link

http://personal.jax.bellsouth.net/ja...ludeaudio.html

If you any more assistance, like which wires I tapped, etc.....feel free to email me.

Ferrd

pIOUs · 05-12-2001, 08:20 PM

Quote:

Originally posted by Ferrd
I was able to run an amp just using the wires that go into the afbs amp in the trunk, with out rca cables. I read this web site, and it gave me all the info I needed to do this. Before reading the web site, I had run the amp from the wires that run the rear deck speakers. It sounded AWEFUL, and had horrible feedback. Once I changed the wiring, and ran the wires from before the afbs amp, it sounded MUCH better. here's the link

http://personal.jax.bellsouth.net/ja...ludeaudio.html

If you any more assistance, like which wires I tapped, etc.....feel free to email me.

Ferrd

Dude...thankyou so much...this was the dead link on the NorthTexasPrelude's site that was dead...yours worked though. I'll look through it....I went out to buy one of those speaker level reducers to give me RCA output that goes into my fosgate amp. It's just been sitting there in my garage and i think I should put it to work...I'll try to work up some pics of the install later...I'm mounting it to the underside of the trunk...with the heavy duty torsion bars installed for the oem spoiler it even stays open by itself...I still have to fabricate a panel that matches the rear deck to shroud the ugly bracing under the trunk...I've test fit everything so far and it looks sweet.
thanks for the reply Ferrd

Ferrd · 05-13-2001, 07:34 AM

I mounted my amp to the back of the rear seats. Looks clean, and hasn't moved yet. I'm also running a fosgate, pushing a 10" JL Audio sub. I'm thinking about getting a second amp to run the fronts. $ is the only issue these days