Hello,

I currently have 00 X5 with DSP and Premium sound. overall I'm kind of not upset, BUT I would like more power. At MAX volume BAPing sounds kick in at times of a Bass, once that you hear from ripped speakers, however they are fine... Now I know that AMP is problem most likely here but I don't want to mess with that, Instead I would like to add 2 more subs, so the sound will get better on low volume also
I was thinking of retroing & placing subs under the front seats just like E60 has it. and of course need an amp. Due to the fact that I am not that familiar with the sound system(did some reading on wiki), I ask your help guys. I would want to know if theese will fit each other. Wanted to post in Electronics section but that saying BSW on it, Didn't want to throw links on it. so here it is, a mono amp and sub:

Kenwood KAC-8105D Class D Amplifiers at Onlinecarstereo.com
Amazon.com: Polk Audio db840DVC 8-Inch Dual Voice Coil Subwoofer (Single, Black): Electronics

What do you guys think?