The stock Bose HU does not have any preamp outputs so you're out of luck. All you can do is tap into the signal wires coming out of the HU and if needed, use a LOC. I have hooked the stock Bose HU to a JL and Elemental Design amp without using a LOC and they work well.

 

Whoop, whoop, whoop. Au contraire mon frere. It doesn't have any RCA jacks.

The signal to the Bose amp from the CLarion HU is by definition "pre-amplified", being before the amplifier. It may or may not be "single-ended", it might be "differential", but it is by definition preamplified.

 

Welcome to the club e el_duderino. I would listen to him. I've seen him in my trunk.

 

I assume that the Elemental Design accepts speaker level inputs??? Or are you talking about the JL Cleansweep running between the two?

 

OK, lemme put it this way.

What speaker level inputs are you going to grab?

The ones with no sub-bass?

Or the ones with no mids and highs?

The output of the HU is probably an AC-coupled differential system using chassis ground as the ground reference. (Been talking to an EE this morning).

Most new amps float the ground on the RCA input. You can take the differential input straight in and lose a couple dB but that's it.

 

I tapped into the signal before the Bose amp and since the Bose HU does not have a built in amplifier, I don't know if that's speaker level inputs. Either way, it had worked with both amps by tapping into the wires and connecting it to an rca plug. If I recall correctly, the ED amp doesn't let you switch from low/high level input but the JL 300/4 amp does. It sound pretty good considering it's a stock HU but I will be adding an aftermarket HU in the near future.

 

I think I finally get the picture on this one. Would it be a bad idea to replace only the front speakers and power them with a new amp and leave the factory rear speakers and sub powered through the factory amp? It seems it should be possible to do this, but the question is whether that will be the best solution, considering the fact that I like 80% of the sound to come from the front in order to create a better soundstage. Basically, it sounds like I should be able to grab the wires for the front coming from the HU as Espresso did and leave the rest running through the factory amp and that seems to be a workable solution. For the wires from the HU, all I need to do is connect male RCAs and throw those into the new amp? Sounds very doable, other than the power cable, which I am certain will provide enough of a challenge for me. Anything I am missing?

 

Maybe I forgot to mention that I used a 4 channel amp to run the front components and rear fills. I disconnect my 6x9 speakers and removed my Bose amp. The only factory wires I used was the signal wires that comes from the HU. I ran wires to each component/tweeter and rear fill speakers. Your idea of using the factory wires and the use of the Bose amp would work but you have to make sure you wire it correctly and cut the factory wires from the amp to the front speakers. Doing the audio upgrade in a G35c was not that difficult aside from running speaker wires through the door molex connectors. The amp power cable is pretty straight forward since right behind the battery there's a large harness that leads into the cabin.