Maybe OT, not sure.

I have a question about car stereo amps. Not really pro-audio question, but amps are amps so maybe someone can help.

I have an 05 Honda Accord. I had upgraded the stereo, installed component Boston Acoustics speakers in the front and rear, and installed 2 JL Audio 10" subwoofers in the trunk. This is powered by one JL Audio 4-channel amp (for the highs and mids), and one JL Audio 2-channel amp (for the subs.)

I had installed a Clarion reciever, which had three sets of line outs. One for fronts, one for rears, and one for subs. The factory radio is very much integrated into the dash, and to install an aftermarket radio you've got to buy an adapter panel which includes all the climate controls. Well I did that for a while, but the adapter panel's controls don't work very well, and the thing is ugly compared to the factory panel, so I decided to go back with the factory stereo.

The factory stereo does not have any line outs, so I installed two line adapters, one on the front output of the stereo, and one on the rear output. This was not a problem for my amps, because I just used the front output to supply my 4-channel amp, then used the rear output to power the sub amp.

The only problem is, there is a lot of noise when I turn the radio (or CD) on, when the volume is down low. When I start to turn up the volume, the sound overcomes the noise and it sounds excellent. But at low volumes there is a lot of noise. Like white noise, or hissing.

When I was using the Clarion radio, it didn't do this. You could turn the volume down and you heard nothing but the music. But with the factory stereo and the line adapters, there is noise.

The line adapters had attenuators on them, I guess in case the output of your stereo is a little too hot, you can cut it back some. I left these maxxed out, thinking that if I need to attenuate it, I'll do it with the gain pot on the amps.

I haven't tried adjusting the gains on the amps yet. I haven't tried anything yet. Just noticed the problem. This is not engine noise, i.e. it doesn't get higher pitched when I rev the engine.

Any thoughts what might be causing this, and any possible solutions?

Thanks. I'll check into that. The main reason I went with the converters I did was because they were the only ones best buy had. But they are also pretty small, which is a plus since they have to go inside the dash.

I'm gonna do some gain tweaking first and see what I can do. If I can get the noise down to a level I can deal with, I'll probably just live with it, because afterall once you get just a little volume going the noise goes away.

It sounds like you've got a stereo reciever turned all the way up with no signal on the input. As soon as you put a signal on it, the noise is replaced by music.