#10991, "RE: Frequency Noises From 6X9's" In response to In response to 5
"You have a ground loop is what you have" -brought to you by the department of redundancy department. (lol, j/k aaron).
aaron is exactly right. ground the new amp to a clean, paint free mounting point...not to the other amp. right now, theres a massive resistance placed on the new amps ground, as it has to travel through all of the other amps "internals" to reach a ground point. because of this excessive load, the amp looks for other ways to ground, and it sees the signal ground as a good place. in doing so, it modulates the audio signal based on voltage changes in the ground (due to the minor, but important, voltage corrilation to the RPM).
on a side note, PLEASE make sure you fuse all power wires. "piggybacking" power wires is a bad idea.
