in my car i have had a 500w amp powering 2 10s for quite some time now but the other day i added a 100w amp for my 6x9s cause one of my deck channels stopped working but now there is a high pitched buzzing sound which usually means a bad ground so i bought some new stuff, ground distibutions block, 4gauge to a brace under the antenna behind the paneling, i sanded down all the paint till i got to metal and got a ring terminal and bolted it onto the brace. from the amps i have 8 guage to the distribution block. i ran a 8 guage wire from one of the spots on the dis. block to the negative battery terminal and i added a 12 guage wire from the headunit ground to that wire that goes to the battery that quieted the sound but its still there. when i unhook the small amp the noise is gone but i really dont think theres a ground issue i think its a problem with the amp. its a crappy old majestic 252. One of my friends said it might be from the ground being too close the power antenna motor, anyone have a better ground spot?