[geeks] Car audio question

[Kurt Huhn]

Slightly more geeky today,

I just installed an amplifier/subwoofer combo in my car - but can't utilize
it to it's full potential.  The reason is, whenever I try to increase the
output the subwoofer will thump and hum.

It *sounds* like it is firing _roughly_ once per three RPMs.  This sort
makes sense to me - since my car is a 6 cylinder.  This is just by me timing
the thumps from the subwoofer - not that I actually hooked up a tach to my
tach-less car and ran it against the thumps.

It sounds to me like I need a line filter for the power lead - but figgered
I'd ask here in case anyone else has come across the same problem.

Any ideas?

Kurt