Engine noise with Crossover, ideas?

[90TSI-AWD]

I just installed a Planet Audio PRC-4 3 way crossover in my hatch area. I have two amps (kicker ZR120 and pioneer GMX552) running to it. The problem is there is a wining coming from the front speakers that corresponds with engine speed. I've been told its the ground for the crossover. I've tried 10 gauge ground wire to sever different spots trunk, the noise stays. I got a noise filter also, didn't do anything. The noise goes away when I just run the amps without the crossover. Please help. Thanks

[91TSIAWD_Mark]

Make sure all of your components ground to the same place.

Or it could be an internal problem in the X-over. If you still have problems with you grounds you could try and install it in someone elses car or excange it cause its defective.

[Endless]

Go to your local shop and ask them to borrow a ground loop isolator. Take it out to your car and try it out. I just sounds like you have a ground loop. it takes about 2 seconds to plug in and test. if the noisei is gone. buy one. they are cheap about 12 bones