installing new head unit in a 5th gen prelude?

[gareth41]

has anyone installed a head unit in a 5th gen prelude? i seem to be having problems getting my back speakers to work because of honda's "accoustic feedback system" which is in all 5th gen preludes. The factory japanese head unit works no probs however i dont just want Mai fm . Ive used a wiring harness on the new head unit and left the factory loom intact. I only seem to be getting audio from the front speakers and not the back speakers. However if i turn the volume up full, the back spakers suddenly burst into life and are extremely loud! If I turn volume down again, the back speakers stop all together. the headunit is a basic JVC KDG-126 model, with 4x 50w output. Theres a factory amp in the truck which powers the back speakers, a friend of mine said there might be a remote wire to power on the amp but I cant find one. However the sir prelude I had a while back in 2006 had an alpine headunit installed exactly the same way with a wiring loom/harness and everything worked no problems, no problems at all with the back speakers. Im 100% sure the wiring is all correct, ive even got a wiring diagram from the 5th gen workshop manual. So now im assuming only certain headunits will work with hondas accoustic feedback system? eg that alpine I had previously? Maybe theres some kind of power difference on the back speaker outputs?

[Chaos]

did you check that all the settings on the headunit are factory?

[gareth41]

yea no settings have been changed, they're all factory

[grandell]

that makes no sense its not a lose connection somewhere?
what exactly does the 'acoustic feedback' system do/comprise of?

[gareth41]

theres quite a bit of info about the acoustic feedback system on the following site
Prelude Audio

If you scroll down the page to where it says "Can I use a new-head unit with the AFBS engaged" thats basicly what im trying to do.

[grandell]

h,,,... well after reading that my advice would be to rip it all out, buy a 2 channel amp and some new front comps. you won't even miss the rears

that doesn't really help you though, sorry

[gareth41]

yeah would like to keep the acoustic feedback system intact, i know its possible to use an aftermarket head unit with that system its just a matter of finding one that works, could be a bit of a challenge as i'll most probably have to try before i buy and a lot of places i dont think will allow that.

[grandell]

a high end headunit and some decent speakers would be a lot better than the feedback system though. but that may be out of your price range

almost sounds like you may need to get a line level convertor for the rears otherwise it overpowers the small (and crappy) factory amp for the rears

[Pauls Audio]

It sounds like the voltage out of the JVC is too high for the input on the factory amp.

We would normally bypass the factory amp, as they are normally only about 8-10w rms whereas aftermarket HU's are 12-18wrms.

See your local Car Audio Shop about possibly trying an intergration module like the Scoshe make.