Fixed the engine whine in my stereo.

This is more of a info thread instead of "help" me thread. I recently bought a Audio Control EQX crossover/equalizer. I run PPI amps and the sound was great but I felt like it was missing something so I bought the EQ. The EQ makes a HUGE difference but as soon as I turned the engine on, a horrendous whine came through all the speakers. Couldn't understand why. All the power wires for the EQ were run with 10 guage wire no longer than 18" directly to the battery. Bought a 20 Amp Noise Suppressor. Didn't help. Audio Control EQX has different settings for the ground to eliminate the whine. Didn't help. Used heavy duty shielded RCA cables. Didn't help.

Then I decided to connect the power wires for the EQ to the power wires to the stereo deck. The whine disappeared. I don't know why and it doesn't make sense but it is gone and the stereo rocks. Just giving some advice to those who are experiencing the same problem and if anyone knows why this works I would like to hear the answer.

I'm guessing that you were dealing with some sort of weird ground loop. Probably an imbalance in line voltage caused the whine.

Do you mean you got a ground loop isolator or a noise suppressor? GL isolators are common for this type of problem. Most high end amps have their own isolators built in, but if yours don't, go to the stereo shop and fork out another $20 for the isolator

Jeff probably got it right; a line voltage imbalance or ground loop. This is common when adding an EQ. Grounding the EQ to the deck and not the battery usually fixes the problem.

I highly recommend that you use a ground loop isolator only as a last resort. GLI's disrupt the signal. They may eliminate the whine, but you'll lose mainly low fequencies in the process.