HowTo: Bypass AFBS Amplifier (Acoustic Feedback System) - Page 2 - Honda Prelude Forum

myorks · 05-27-2010, 06:03 PM

yea I have all JL audio so idk

dric · 06-13-2010, 09:52 AM

This thread is a very useful thread i tried it yesterday and it worked out well i'm loving the new sound from my speakers

Kronn 98SH · 06-13-2010, 11:34 AM

Yw.

skyyskyy · 07-10-2010, 06:32 PM

WOW! Shoulda done this along time ago. My crappy wal-mart pioneers now sound like crappy wal-mart pioneers only a hell of alot better and i dont have to turn the volume to almost max to hear the rears. Thank you verry much kind sir.

kfuto · 08-20-2010, 04:45 PM

According to the main post, if I decide to keep the AFS, it will reduce the volume output of the rear speakers when I change my deck?

My thought of plan was, since my new deck only allows 4-8 ohms per channel, and the stock speaker is only 2 ohms, I was gonna put a spare set of speakers in series with each one of the stock speakers to bring up the impedance. That way I could connect it to my new deck, without having to purchase a new set of speakers right now (money's tight!). But I was thinking of keeping the AFS, since it does a nice job currently. Do you guys believe that this is ill-advised? Should I just bypass the darn thing? I just figured it would provide better sound since that's what it was designed for.

And if I decide to keep it, are there any ramifications with having the AFS hooked up to the new deck (power differences), and/or with having now 4ohms or more per channel (since I'm putting each stock speaker in series with a spare one) hooked into the output of the AFS?

I hope my questions are clear enough...thank you in advance for any & all responses!!

BTW - This is in no way trying to disrespect the original poster's (Kronn 98SH) opinion regarding the AFS, but I disagree with the statement that the head unit has a 2-way communication with the AFS. Reason being is that from the head unit, there's a constant power output, the power switch output, and the speaker output terminals feeding into the AFS. There are no signals being sent from the AFS to the head unit, since there is no allocated wire for this purpose. Hence there's no 2-way communication between the two units. Just my 2 cents, but certainly open for discussion.

skyyskyy · 08-20-2010, 05:06 PM

According to this the afbs makes the rears mono and by removing it and rewiring brings them to stereo. Prelude Audio That was probably the biggest diffrence i noticed other than not having to turn my volume up half as high to hear, my rears no longer just spit out low's but use the tweeter(3 way) now also. The one thing i missed about my 4th gen was the stereo untill i did this now its up to par.

kadidle · 08-26-2010, 11:54 AM

Quote:

Originally Posted by kfuto

BTW - This is in no way trying to disrespect the original poster's (Kronn 98SH) opinion regarding the AFS, but I disagree with the statement that the head unit has a 2-way communication with the AFS. Reason being is that from the head unit, there's a constant power output, the power switch output, and the speaker output terminals feeding into the AFS. There are no signals being sent from the AFS to the head unit, since there is no allocated wire for this purpose. Hence there's no 2-way communication between the two units. Just my 2 cents, but certainly open for discussion.

I agree, not only from what you said but if you take the rear microphones out on the speakers and talk into them or blow into them you can hear it through the speakers. I have the stock sound system and an aftermarket head unit and my feedback system still works and quite well. If you dont have the original speakers then removing the afbs is a good idea.

chubbs · 01-07-2011, 12:20 PM

Excellent write up, and simple to do.

leftbrain99 · 01-07-2011, 12:48 PM

Quote:

Originally Posted by kfuto

BTW - This is in no way trying to disrespect the original poster's (Kronn 98SH) opinion regarding the AFS, but I disagree with the statement that the head unit has a 2-way communication with the AFS. Reason being is that from the head unit, there's a constant power output, the power switch output, and the speaker output terminals feeding into the AFS. There are no signals being sent from the AFS to the head unit, since there is no allocated wire for this purpose. Hence there's no 2-way communication between the two units. Just my 2 cents, but certainly open for discussion.

Since someone else bumped this thread, I have to add my +1 to ^ this post. There is no feedback signal sent to the head unit. Check the wiring - only outputs from the head unit to the trunk amp. All of the feedback circuitry is in the amp. I made a similar circuit for a class during my undergrad at Georgia Tech. The amp listens to the speaker output and adjusts gain based on distortion it senses.

Great write up, though! And a lot of work put into it, as Kronn always is thorough. Just a bit of misinformation in the first post. :-D

Kronn 98SH · 01-07-2011, 12:53 PM

Yeah, I worded it incorrectly and I'm too lazy to go back and fix it.

chubbs · 01-08-2011, 12:45 PM

So, I did this today, the first set of wires without a problem.

Then when it came to do the speakers, the colors for my 97 were different. For ****s and giggles I decided to see if my speakers worked, and they did. So obviously I bypassed the system, is there any advantage in cutting that 4 pin connector?

Kronn 98SH · 01-08-2011, 12:54 PM

The clip that connects directly to the factory speaker? I left mine so it could easily be reverted back to stock.

What colors are your wires?

chubbs · 01-08-2011, 01:08 PM

Oh, I understand it now. I still have the stock speakers in mine, so I only needed to change those clips if I have after market speakers correct?

Because now that I think about it, that has to be done for after market speakers anyways. Wow, I feel dumb now haha.

MountianLude · 01-08-2011, 05:30 PM

Quote:

Originally Posted by Kronn 98SH

So if anything is aftermarket in your audio system, you might as well bypass it.

So even with after-market speakers and a stock head unit the bypass will help?

Kronn 98SH · 01-08-2011, 06:07 PM

Quote:

Originally Posted by MountianLude

So even with after-market speakers and a stock head unit the bypass will help?

Especially with aftermarket speakers. Look at their ohm rating.

LudeMike · 02-27-2011, 01:42 PM

Here was my situation if anyone is in the same boat and considering doing this...

Stock head unit took a $hit, bought a cheapo sony xplod from walmart, front speakers went as well, got me some infinitys. Noticed after installing the new head unit and front speakers that my stock back speakers sounded blown. Followed this guide here to bypass the AFBS amp, now my stock back speakers that are 10 years old sound NEW.

Appreciate the write up Kronn

, speakers sound WAY better.

Unvrs421 · 12-26-2011, 02:02 PM

Should I put the afbs box back in after i do the bypass? I noticed in one of you're pictures Kronn that your box was still there after you did the bypass. Im just a tad bit confused on this note. I did the bypass already, however i havent plugged the afbs back up yet. The speakers are still producing sound though.

Kronn 98SH · 12-26-2011, 02:55 PM

I have the box installed but disconnected. This is simply so that I could revert to stock instantly if I decide to sell her. Plus, I didn't want to lose it.

Unvrs421 · 12-26-2011, 03:06 PM

Ahh, just as a suspected! Well thankyou sir, this write-up made this project work with ease. :P

DaHonga · 12-26-2011, 07:42 PM

Great write up, will try this soon!