Depends on the music too but I've heard one ported out perform 2 sealed before myself too.

Back to the OP, these are ridiculously expensive but perhaps could be reverse engineered if you're short on cash.

http://thunderforms.mtx.com/p_34/Ran...1997/show.html

__________________
Garth

2011 Ford F150 XLT 4x4 EcoBoost, Gray/Silver

2005 Volvo XC90 [more than just a grocery getter!]

1987 Olds 442 27K Original Miles