Picking up audio signal pre amp on Navi 03+

[ibrahim83]

I currently have my system as follows,

USA Spec bt45 --> Head Unit --> Factory JBL amp --> Mosconi 6to8V8 DSP --> JL MX amps in the cargo area --> infinity components & JL sub.

Is there a way to bypass the JBL amp? the reason i went with the plan above was that the schematics for the car only show + and - speaker pair only after the amp. Into the Amp the signal shows LF+ RF+ LR+ RR+ so i'm assuming it's a common ground system if i understand correctly.

Now you may wonder, why before the amp and not stick with the current solution, Well,

1. I have some static noise present when the truck is running. It is NOT rpm dependent and i'd like to set the gains properly and get all the power i can, but that adds a hiss i can hear.

2. i want to bypass any time correction, amplification and EQ from the factory system with the belief that it would give me a lower noise floor and clean sheet to work with.

The other solution is to connect via 3.5 to RCA to the input of the DSP OR buy a BT streaming dongle setup for the DSP ($$$!!) and loose steering wheel controls, volume/track control from head unit, and no song info, as well as loosing any sounds the car generates through it's speakers.


ANY help would be appreciated.

 

[jerryb]

you should read all the threads on stereo, ground loop, static noise, etc. There's few with processors around here. I think they all have mediocre luck with them. Speaker grounding loop-whine with engine that thread there explains. If you haven't read that already.

I ditched the whole thing.
but to maybe answer your question. I ran aftermarket amps with high level inputs bothe pre and post stock jbl. The sound was horrible. You can play with the gains but it's still there and you know the amp isn't doing it's job. It also heated up a JL and RF amp quite a bit.

 

[ibrahim83]

Don't get me wrong. By all accounts my system sounds great.i can turn it all the way up with zero distortion, but i want that extra volume for freeway cruises with my windows down. i want to get the last 10-20% out of my equipment.

the noise is only heard when you put your ear up to the tweeters. if i turn up the amp gains i end up with an unacceptable level of noise (to me)

Thanks for your help though. Also, i firmly believe the amp in the 02 and earlier years is not the same as the 03+ and i would take that out if i ever do a HU install.