I am replacing the bose amp in my coupe, but am having some problems with the wiring diagram. It shows signal leads from the HU to the amp as a positive and a negative for the right channel and the left channel. Each of these leads is shielded. It looks like these are not low level leads as I thought they would have been. They look like there is a positive and a negative for each side, like you would see going to a speaker rather than an amplifier. These kind of leads are usually not shielded. So my question is: Are these leads high or low level leads? If they are high level(speaker level) leads, then I will need an LOC. If they are low level, then I will need some way of converting to an RCA, because my amp accepts only RCA input. Anyone got any ideas?

Thanks

 

It depends on your amp if it is able to support High Level Inputs... otherwise, as you said, you'll need a LOC. I got an JL amp, and I don't need a LOC.

 

I used an oscilliscope and measure the output of my 2004 coupe HU at 2.2V peek to peek........No need for a LOC to reduce the voltage further.

 

so if that's the case, then how do I combine the shielded positive and negative into a single RCA? That is one of the functions of an LOC. Can the LOC perform that function without attenuating the signal? Would a line driver work in this situation?

 

Any takers on this subject?

 

The LOC will attenuate the signal and a driver will amplify the signal. The way I wired my system is to tap into the factory wires in the trunk going to the blose amp (search a thread here for the wire colors) by stripping the appropriate wire without cutting it in 2 (this way the factory "stuff" can be put back in if I want too). There will be a + and - for each channel, left front, right front, left rear and right rear for a total of 8 wires. Each RCA required 2 wires, a + and -, 1 RCA for each channel or 4 RCA connectors..........now after I said all that I have a noise problem........there is some noise on my factory input signal wires that I cannot figure out where it is coming from.......I am about to run my own RCA cables from the trunk to the HU and splice into the HU wires under the dash........you see the factory stereo wires are bundled with all sorts of wires (brakes, turn signals, power wires ect.) in the wire loom going into the trunk. I am assuming this noise is caused by all these wires bundled together, but right now I am still guessing!

 

You said what each of those devices do, but did you use one? The problem you are probably having is with the shielding on those positive and negative wires. If you tapped them and pinched the shielding with the wire, you will get that noise. According to the wiring diagram the shield is connected on the HU end. If you are going to run new wires, make sure you use a twisted pair, or twist them yourself. This gets rid of the ground loop noise, could be causing the problem. If it is high frequency sheilded wire is best, but low frequency stuff like alternator whine is fixed with twisted pair wiring.

 

I used a LOC and found the signal too low for my tastes......so I wired the HU outputs straight into my xover.......but I checked to output with the oscilliscope to make sure I was not exceeding the 8V maximum for my Coustic xover, which I found out the HU output was only 2.2V peek to peek.......low but still good enough so I did not use a driver...........I'll check on the shield thing tomorrow.........I have a friend at work who used to work installing stereo's and hope he can explain this better.....if not I'll be back tomorrow with more questions thanks for the direction, I need it... I am so frustrated with this problem.....just wish it would go away! lol

 

Anyone make a harness that would connect to the wires going to the Bose amp, so we don't have to worry about cutting the wires?