I am currently building a system for my 93 Chevy Caprice. My substage is a Hifonics Colossus 3200 watts RMS amp on 2 XL 15'S M2. My box is right at 6.65 net after all displacements tuned to 33 hz. Here is my question I have a Audiocontrol EQS with a built in 33hz subsonic 18 db octave filter. Keep in mind this works on a chip and is not selectable. I have not hooked this system up yet because I am still buying all my electrical. My question is should I buy a different chip to go with 25, 30 hz or stick with the 33 hz subsonic? How low should I be able to play under tuning without risking damage to the woofers. I really want this set up to be a low end monster