I've got a 2004 trailblazer with 1 Memphis PR
-15s4v2 with a Memphis pr
-500.1 amp. I have a box I built to Memphis specs but its tuned to 47hz. Its 2.5 cubes after sub and port displacement. Ive been building boxes for awhile now but I've always built them to the woofer specs with plans already drawn out. Im looking for lower response than I have now somwhere around 35-40hz. If the info I gave sucks im sorry ill learn from mistakes but any help giving will be greatly apriciated thanks.