Originally Posted by PhotoWrangler
I'm currently researching how to remove the front passenger seat safely without interrupting the airbag system.
If you installed the amp under the passenger seat, I don't see why it would disrupt the air bag system, if it didn't disrupt it when you installed the amp.
What I would do, as Big Sarge suggested, is shorten the ground cable. I would cut the ground and screw it into the tub under the passenger seat, as far as is safe. I wouldn't have the ground connection right next to the amp, but a foot away or even eight inches. When, you place the ground, make sure it is underneath the carpet, and clean the paint from the ground hole that you drilled for the ground connection. Also make sure that there is nothing being drilled through that would disrupt other systems. I would also check the grounding straps under the hood to make sure that your tub is properly grounded.
You might also want to trace your headlight wires, and see if they are right next to your amp power cables.
You might also want to determine if certain functions make the hum go away. For me, the GPS didn't hum, nor did my CD player. But, my Aux-in had a big hum. So, I was able to address the Aux-in as the culprit. I also noticed that my cigarette lighter cell phone charger increased the hum. I just put a noise canceller on my aux-in port and it solved the problem. It might be different for you. On other vehicles, the ignition power was the culprit, and I put a noise canceller there to solve the problem.
An amp might also magnify a slight hum that is already present. So, you might want to check your radio grounds to make sure that they are good. If your firewall and tub are not properly grounded, by the straps under the hood, then it might not be the amp that is the problem, but the radio hum, which the amp is magnifying.
Cheap components might also be the problem. In which case, a noise canceller may solve the problem.
If you are tapping into the headlight power, instead of the dedicated radio connections, this might also be part of the problem. But, I would start by eliminating all possible grounding problems.