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 **** 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.

oneprelude

good ish

gstrudler

I'll have to throw a meter on the stock rear speakers and amp sometime to see what they're running. I recall hearing that the stock speakers run at some funky resistance that is matched with that amp back there, hence aftermarket speakers not playing well in that position. I will argue that the stock speakers still works quite well with an aftermarket headunit. While certainly not comparable to a high $ hi-fi system, it actually puts out good response with some eq work. I was plenty surprised with the bass response out of those 6x9's with my Alpine HU. They are hitting 100hz or better very well, probably down to about 75-80hz with good response. I still plan to add a sub in the trunk eventually to fill in that area between 40-80hz, and the front tweeters don't seem to do much above 8khz or so.

That being said, if the speakers are toast for some reason, this is a good write-up to guide installing aftermarket speakers. Someone can reference the helm's or etm (I'm out of town right now), but I don't think the stock HU is required for the AFBS, I think it's all done internally at the amp iirc. There aren't any extra lines running to/from the headunit, it's a standard connector.

Kronn 98SH

From PP.com

I don't want it to turn into an argument about exactly how the AFBS works. The point was merely to show how to bypass it, since there is reason for doing so.

allentownrep

So im going to assume that this is only for 5th gen preludes?

BlackCatt

^ yep, 4th Gens dont have it.

Wing Nut

Wow, sorry to revive such an old thread, but I've been planning on doing this modification for some time now but now I have some questions.

My original speakers were completely rotted out, so I replaced them with Pioneer components (all six speakers). I simply used the original harness as much as possible, and kept the rear microphones intact by fastening them to the rear speakers in the same position as the originals.

My sound is very balanced, and I have nothing to complain about (such as the fronts being louder than the rear, etc.) However, I have a couple other issues. First, when I adjust the fade to the rear, and then try to single out left and right, both speakers decrease volume equally. Is that just because the AFBS makes the rears mono?

Second, while the volume levels are balanced, it seems like I only have highs with a decent amount of lows. My midrange seems exceptionally weak. Does this have anything to do with the AFBS, or is it just my speaker choice?