Kronn 98SH

This is for all of you who have aftermarket head units and would like the rear speakers to sound better.

First, let's discuss how it works. The Acoustic Feedback System is a 2-way, self-checking process. The head unit sends the signal to the speakers. The speakers produce sound. The microphone built into the stock speakers takes that sound and sends it back to the head unit. The head unit listens to the sound and alters the output to correct what it heard. The idea is to get better sound quality by reducing hiss, feedback, etc etc etc.

Now, let's discuss how/why bypassing it is better. AFBS only functions if you have the stock head unit AND stock speakers. Some might argue that (one name comes to mind). I don't care. So if anything is aftermarket in your audio system, you might as well bypass it. The reason is that the "amplifier" box used actually reduces the speaker output, at least once you have aftermarket goodies in there.

So, back story: When I first got my Lude (6 years ago), I replaced the stock head unit, stock rear speakers, and blown aftermarket door speakers (but not tweeters as they were already disconnected). Upon installation, I noticed that in order to hear the rear speakers, the fade setting had to be put almost all they way back. This reduced the total volume output of the system, which required the volume knob to be turned to max just to get a good listening level. BAD. About 2 years ago I again replaced the head unit, and this time I replaced all 6 speakers with 8 new component speakers, 6.5" woofers with 1" tweeters (Pioneer TS-A1702C for front AND rear). Again, the fade had to be set almost all the way back and again the volume wasn't loud enough. I realized the AFBS was the problem. After completing the following steps, I found that the rear speaker output increased approximately 600-800%.

So here we go.

Tools Needed:
1 - Light Source (trunk light isn't enough)
1 - 8mm socket & ratchet
1 - 3" ratchet extension
1 - Wire strippers
4 - Wire butt connectors
4 - Speaker wire clips
1 - Wiring diagram (see below)


Step 1: Download and print this diagram.



Step 2: Unplug and remove the "amplifier" box.




Step 3: Cut the 8 OUTSIDE wires on the plug (4 on left, 4 on right).

Step 4: Reconnect wires according to the diagram. To make it easier, here's how they go.

LR+ Blue wire w/ Yellow stripe (pin7) to Pink wire (pin1)
LR- Gray wire w/ White stripe (pin17) to Yellow wire w/ White stripe (pin9)
RR+ Red wire w/ Yellow stripe (pin8 ) to White wire w/ Yellow stripe (pin2)
RR- Brown wire w/ White strip (pin18 ) to Light Green wire w/ White stripe (pin10)

It should look something like this.



Step 5: Locate the 4-pin connectors for each speaker.

Step 6: Cut them.

Step 7: Attach speaker clips to correct wires. To make it easier, here's how they go.


LR+ Pink wire ~> Big speaker clip
LR- Yellow wire w/ White stripe ~> Small speaker clip
RR+ White wire w/ Yellow stripe ~> Big speaker clip
RR- Light Green wire w/ White stripe ~> Small speaker clip



Step 8: Connect speaker wires (with clips) to aftermarket speakers.

Step 9: Set your fade back to even and enjoy.

__________________
1988 Prelude S - victim of an 80mph backflip
1991 Prelude Si - sold
1989 Accord DX - impounded
1998 Prelude SH - totaled on 3/29/12
2006 CRF150F - sold
2006 YZ250F - sold

fastkill

r/t?

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dontbuyprelude

i took the spade terminals off oem speakers and put em onto my rockfords. i just pulled em off. this way, i can disconnect my speakers still using the factory connectors. i just snipped off the afbs microphone wires. and i connected all the wires to bypass the afbs right next to the afbs connector.
pin7>pin1
pin17>pin9
pin8>pin2
pin18>pin10

has worked flawlessly for the last 2 weeks

Kronn 98SH

That's rather pointless, and wrong pins for RR. You didn't bypass the amplifier.

__________________
1988 Prelude S - victim of an 80mph backflip
1991 Prelude Si - sold
1989 Accord DX - impounded
1998 Prelude SH - totaled on 3/29/12
2006 CRF150F - sold
2006 YZ250F - sold

dontbuyprelude

however pointless the connectors idea is i still like it. my afbs is most certainly disconnected as the afbs unit is in my garage and my rear speakers produce sound. pins for rr are correct. i got it straight out of the helms. my 2001 may be different then your year. which i believe is 1998.

Kronn 98SH

There is definitely a discrepancy. Helms shows one thing, my ETM shows another. Someone else also pointed it out on PP.com. I can't confirm which is correct now, but I should be able to in the near future.

__________________
1988 Prelude S - victim of an 80mph backflip
1991 Prelude Si - sold
1989 Accord DX - impounded
1998 Prelude SH - totaled on 3/29/12
2006 CRF150F - sold
2006 YZ250F - sold

KraserK

Kronn you are a legend I was looking at doing this soon but wasn't too sure on how to do it! Thank you kronn! Happy new year too!

Kronn 98SH

Discrepancy with Helms has been corrected.

__________________
1988 Prelude S - victim of an 80mph backflip
1991 Prelude Si - sold
1989 Accord DX - impounded
1998 Prelude SH - totaled on 3/29/12
2006 CRF150F - sold
2006 YZ250F - sold

myorks

my car came with a nice alpine deck, and JL Audio evolution speakers all the way around...bangin sound....the only thing about it is the back is noticeably louder and I figure because they are bigger speakers in back..one question....when I turn my volume up really loud the lighting/buttons on the deck lightly blink with the bass of the song...lol its always made me wonder why???

dontbuyprelude

im not an expert by any means but maybe the previous owner wired the pos wire into the factory harness instead of a heavy gauge power wire through the firewall and directly to the battery.

dontbuyprelude

i know when i had my del sol a while back my lazy brother wired up my whole stereo using the tiny factory harness and about 10 mins into playing some music my whole stereo turned off. apparently i melted or burned the factory power wire in the harness. so i ran a decent power wire straight to the battery and i never had that issue again.

Shimee

The headunit supplies power to the rear speakers. They're obviously powerful and draw a lot of current, so at times the supply wont be enough to keep up and will discharge slightly too much to the rear speakers.

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03yama

found this helpful too

bypassing AFBS system (5th gen)

myorks

yea this is what i was thinking as well...I know JL audio evolutions are very good speakers and I can tell the wiring is not stock...the deck is also a 60w x 4, not sure if that makes a difference being that its a bit higher wattage than average

Joaquin Olivas

Could I just run aftermarket wiring to the 6x9's and completely remove the AFBS??

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"Go ahead and upgrade the slush box, blow it up, and sell it. You had fun for awhile, right?"
-nimrod8560

myorks

I read this today again and was checking my trunk out and I know the bypass job was done by the last owner. I am now wondering why my rear speakers are seemingly a lot louder than my front speakers. I know that you can adjust the fader and everything but when everything is centered, My front speakers can be heard but are fairly drowned out by the rears(yes I know they are bigger). Just wondering if there is any meaning to this?

Also I recently have had problems with my driver side front speaker. It does not work now unless I have the door open and mess with the harness that goes from the door to the body of the car, and when I do it cuts in and out or sometimes works until I shut the door. Do you guys know if this would be a wire shorting out or something? My friend said I might have to take the door off and re-wire the speaker(God I hope not fml). But any help would be nice.

Kronn 98SH

Yes, if you want to run new wire from the head unit back to the speakers, you can.

Probably 2ohm vs 4ohm.

__________________
1988 Prelude S - victim of an 80mph backflip
1991 Prelude Si - sold
1989 Accord DX - impounded
1998 Prelude SH - totaled on 3/29/12
2006 CRF150F - sold
2006 YZ250F - sold

dric

interesting thread i'll try it out tomorrow and see what happens

ColinK

I used this write up and it worked, except I messed up left/right speakers. Kronn is right, the ohms is the reason backs are louder you have to now get aftermarket fronts or just shift it like +2 to the front.

indylude18

That is a much better solution if you are running beefy speakers in the rear. The best solution is to hook up an aftermarket amp, which bypasses the AFBS and all the factory audio wiring anyways.

If using the crappy stock speakers, then that is the likely cause. However, nearly all aftermarket speakers are 4ohm. In that case, differences in the sensitivity of the front and back speakers are causing backfill. Remember, the higher sensitivity rating, the louder a speaker will be at a given wattage.

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