Only one way to find out is to try a different set of subs. Boxes are usually designed specifically for the subs they come with. Just throwing any subs in it can hender the performance.
That as well. But when I put my kicker in it I noticed a noticeable but good difference
Sent from my DROID RAZR using Tapatalk 2
http://www.grandprixforums.net/my-06-gp-gxp-72403.html OBX headers, TEP tranny cooler, ls1 IM fuel rails and injectors, ls2 TB, ls7 MAF, full custom exhaust, Quad retro headlights, full out front and rear suspension work, tuned by HPT by me 8====>