Sub/bass Thumping with new deck

[aesic]

I just bought and installed a Premier DEH-P770MP. After installing it, I now have a constant thumping from my sub. The intervals between thumps don't speed up/slow down according to driving speed or anything, but it does sometimes speed up/slow down randomly and sometimes gets lower or higher randomly. It is not noticable at high speeds (due to road noise) but at low speeds or at quite parts in songs it is. I didn't change anything with the sub/amp setup. I recut and crimped all the wires for the harness so that could be where I went wrong. What part of the wiring the deck could I have messed up? Is it a grounding problem or something? Not to experienced with stereo wiring/problems so any help would be really appreciated. Thanks.

-aesic

[PoorManQ45]

YOu may be maxing out your electrical system.

If that's the case then it'sd time for a higher output alternator

What are your main speakers?

[aesic]

4 - 4x6 Infinit Kappas. The amp is 250w and the deck is 22w x 4 rms. I probably still have the stock S13 alternator. Would it be the alternator or battery? Everything works fine, I just have the low pulsing of the sub.

-aesic

[PoorManQ45]

Might be the alternator, but I don't think such a small amp would cause that problem.

How old is the battery?

It's possible one or more of the grounds are bad

[aesic]

No clue about the battery. Its what was there when I bought the car. What grounds could be bad? Nothing on the amp has changed, and I'm pretty sure the ground on the deck is good. Its just the thicker black wire right?

-aesic

[PoorManQ45]

yep, thick black wire is the ground for the deck

I would recommend cleaning the grounging point for the amp, then clean as many of the grounding point in the engine compartment that you can find.

Also I'd recommend that you make your own ground kit. Use 12 awg speaker wire. Run one to each strut tower, one to the existing one on the fire wall.

Note when I say run to, I mean from the negative battery terminal