surface area normally would take the cake .. ive heard both ... and up agianist each other the q is the winner but ... not a big 2.5 fan didnt like the sound of it .. might of been the box but it sounded muddy imo ... 2 of them however will get loud and depending on ur application and from what people say in a good box will sound good
well i acually calculated the space where im putting the box and i can fit a 8cu^ft box (net after port area) in the back of my jeep cherokee sport. so im thinking 2 15's would fit just nicely but i'm kinda pushing towards 1 Q for now and save up for a second in a few months. So ur saying the Q is better then the SD2.5
