[07SEV6]

I'm hearing this low whinning noise coming from my engine through my speakers after installing my new sound system. After doing some research in the forum, it seems like I might need a ground loop isolator. I kept the factory JBL upgrade headunit w/o the navi, JL audio components in the front, JL audio 3-way 6x9's in the back, JL audio cleansweep, 2 JBL amps, and a JBL subwoofer. The guy who installed it said that he did all he can do to minimize the noise. I trust his work because he was highly recommended by some ppl I know. But I didn't check the grounds from the amps or how he ran all the wires. I only hear this noise between songs. Other than that the sound is great, but it would be nice not to hear this low whinning noise. If I do need ground loop isolators, will I need to buy one for each channel and how do you install one?

 

[gdanaher]

What you are describing is likely alternator whine and can be verified by alternating the rpm of the engine and listening for changes in the frequency of the whine. Verify that the ground is in fact grounded to the body and try to avoid going through the normal fuse boxes for the positive power. Also try winding a choke on both the positive and negative sides using #43 toroid material. Alternately, solder a .01 mF capacitor across the contacts of each speaker and this should also attenuate the noise you are hearing.