[headrott]

I am using an Alpine 7525 head unit, and line level RCA with seperate
outputs from the HU meaning seperate inputs on the amps. No Y-ing
involved.
I don't think it's the HU because I had 2 3522's hooked up to it
(front/rear) and they worked fine. Then the front 3522 was stolen. I
was using just the rear 3522 and it worked fine (after the front was
taken). I then rewired my car (new positive and negative wires, but the
same RCA cables and speaker cables) and that's when the problems
started.

Yje problems aren't exactly the same in the front and rear, but
extremely similar. It's mainly the rear that does the rapid
thump-thump-thump. But both the front and rear have very faint and
distorted sounding signals coming out of them. Thanks for your help.

MOSFET wrote:
What HU are you using? Are you using line-level RCA inputs or speaker-level
inputs? So both amps do EXACTLY the same thing? Do they each have seperate
inputs from the HU (like front and rear)? In other words, are you Y-ing a
signal and then sending that to the amps or do they each have their own
seperate inputs from the HU?

If you are sending a front signal to the 3548 and then a rear to the 3522
(I've used that amp, it's a GREAT little amp), is each amp doing EXACTLY the
same thing? If so, it's safe to assume that the problem is related to your
HU or how you have your HU connected to the amps, not the amps themselves.
But we need a bit more info first before we can narrow the problem down.

MOSFET

"headrott" wrote in message
oups.com...
I am installing 2 (2 channel, obviously) amps (an alpine 3548(for the
front) and an alpine 3522 (for the rear)into my car (1993 BMW 318is). I
have the positive cables hooked directly to the battery and and the
ground cables grounded to the floorboard.
The problem is that when I turn on the HU, the amps power up fine but
when I go to turn up the volume (from 0) there is a loud thump on all 4
speakers and the audio that comes out is very weak (even when you turn
it up loud). Also, sometimes on the back speakers (comming from the
3522) the speakers make a constant very fast thump-thump-thump-thump.
The volume of this is a medium volume even when the volume on the HU is
only on 1 or 2. I have tried messing with the ground wires multiple
times, but with no luck. I am at my knowledges end, so please someone
help me figure this out. Tank you for your time and help.