Just installed ecodes, audio buzz when lights are on

[Kid Red]

When I turn the just installed ecode bi-xenons on, I get a buzz over my speakers (aftermarket amp). Not sure how or why the lights introduced the buzz, is that a ground loop problem? How can I fix this?

[OEMplus.com]

Yes, grounding issue...

[Kid Red]

Any suggestions where to start or what to look for?

[haus4]

Does it buzz wen the lights are only on? If so you have a "dirty" power source. Do you have a capacitor? Check the actually connections to the body. It could be also that ur alternator doesnt have enough amps. In my friends A4, when he turns it up, the dash lights flicker

[Kid Red]

No buzzing. The battery is brand new and I've checked the voltage quite a few times and it holds strong.