Replacing rear speakers on 5th gen - Honda Prelude Forum

losborne · 09-02-2007, 10:07 AM

Has anyone ever replaced their rear speakers with aftermarket speakers while still using the feedback system? If you did how did you do it? The reason I ask is that I just had to replace one of my front door speakers which gave up on life after ten years (98 SH). I looked around and settled on some Sony speakers mainly because of the mounting depth and the fact that they had universal mounting holes which lined up right on with the original speakers. They weren't my first choice but dimension-wise seemed to be the best fit. Well to sum it up they are a nice improvement over the originals, sound and volume, and for only 70 bucks. This got me thinking about the rears. It actually looks like you could use the speaker wiring that is in place since the harness already has the speaker connections, and it appears that you could remove the feedback microphone from the speaker and just let it hang there.
The possible problems I see are that the system may not work without the microphone attached to the speaker, and its difficult to find 2 ohm speakers, however it would be nice (maybe) to have stereo sound from the rears rather than mono sound. Any input appreciated.

PininFarina456 · 09-02-2007, 02:13 PM

The car audio place that installed my speakers was able to keep the AFBS with the speakers since I am still using the stock head unit.

CIT_lude · 09-02-2007, 03:42 PM

The rear speakers are run from a strictly conventional output from the HU. There's a small box near your back speakers which houses a small amplifier and the AFBS circuitry, and this circuitry receives signals from small microphones implanted into the rear speakers. The signal is adjusted at the amp and sent back to the speakers with no input from the HU at all. This means that you can get an aftermarket HU and still keep AFBS functional, but not aftermarket rear speakers (unless you figured out how to swap in the microphones on your new speakers).

Incidentally, my largest gain in SQ came from swapping in a new HU. If you consider buying even a cheapo alpine unit, you can bypass the AFBS/amp and run 4ohm speakers in the rear, which will open up a large range of speakers. Personally, I'd be surprised if I could pick out the difference between AFBS-modified and straight-through sound, although I'm not really an audiophile either. Hell, I've got my rears disconnected entirely

I would guess that the SQ increase from going to an aftermarket HU & rears would far outstrip any gains you're seeing from AFBS.

Brash22 · 09-02-2007, 04:36 PM

What's all this talk of AFBS, I've never heard of it?

What I did was swap in a decent set of 6x9s. Then I went crazy with a set of Polk Momo Carbon splits in the front MB Quart splits in the back, Polk Audio subs and a couple of Alpine amps. I mixed those ingredients well, and after cooling, it's served loud and clear.

PininFarina456 · 09-02-2007, 07:00 PM

^^AFBS = Acoustic Feedback System

losborne · 09-03-2007, 07:44 AM

My bad. I just realized what I described would still only send a mono signal to the rears if AFBS is still used. For anyone who just disconnected the AFBS and used new speakers that were full range what did it sound like? Does the original head unit have enough power to drive new speakers or did you need an amp?