engine noise

Hi. I just put a system in my friends car. Consists of a Sony head unit. Two 100 watt Rampage front speakers wired into a 150 amp Nakamichi amp. Two 290 watt JVC 6 by 9 in the rear, along with two 12 inch Kickers, that are wired into a 300 amp amp. The woofers are also routed through a cross over. Also I have the power going into a distribution block. The grounds are also ran through a power block. We tested the system afterwards and there was no engine noise. Shut the car off and started it again and the engine noise came back. Does anybody have any advise on what the problem could be. I know that the constant and ignition power are crossed in the head unit. I am going to fix that tomarrow. What could it be?Derek Ronning

When you say the woofers are routed through a crossover, are you talking about an active electronic crossover?  If so what brand is it?  Where is the noise coming from, the woofers or your other speakers?  If out of the woofer only, have you tried bypassing the crossover to see if the noise goes away?

I have had basically no luck when I use an external crossover. Basically all they do (besides what they are supposed to do) is magnify any possible noise in your system or in my case, cause noise. In my opinion, I dont like them at all. The amp's crossover is fine for me. But I would do what "i am an idiot" said. Simply bypass the crossover. If the noise goes away, then you have a bad ground for the crossover and is causing a ground loop.

i just narrowed the problem down to hte cross over. it is a pioneer electronic cross over.Derek Ronning

". . . external crossover. Basically all they do (besides what they are supposed to do) is magnify any possible noise in your system or in my case, cause noise". Thousands of external X-overs have been installed with no problems. Before the internal stuff your only choice was outboard. Installed correctly they are perfectly exceptable and some,the quality is beyond what comes internal with the amp. Pioneer stuff has grounding issues. Decks especially. Since you haver found it to be the X-over, try opening the case and look for burnt traces or something shorting against the case.