I'm trying to decide on a sub for my car, and design an enclosure for it. I listen to a lot of drum and bass, so due to the wide range of frequencies, I've already decided to go with a sealed enclosure, and I have a Hifonics BXi 1606D to power the sub. My original plan was to go with a 10" Q, as I figured it would be more than loud enough, even sealed. The issue I've run into, however, is that I want to mount the amp on top of the box, to keep things more compact (take up less trunk space), and to make the box and amp easily removable for autocrosses. The problem I'm having is that once I make the top of the box large enough to hold the amp (~11.25 x 14.5), and make the box tall enough to fit the sub (~12" high, leaving only 1/2" on each side), I end up with an internal displacement of ~.77 cu. ft., which gives me .65 cu ft. after accounting for the displacement of the sub. That's outside the recommended range for the Q 10 of .2-.6 sealed. I also wanted to slope the back of the box, so that it fits flush against the back of the seat, but that makes the volume even greater. So, here are my choices: 1. Make the box as I described, without a sloped back - the enclosure ends up a little larger than 'ideal', and doesn't fit perfectly in the trunk 2. Move the sides of the box in, so the top is the same size, but the ends are recessed, reducing the box volume down to a more ideal value amount (if I do this, what should I aim to make the displacement, in the .2-.6 range?) 3. Step up to the 12" Q. The disadvantages I see here are that, with the new target of ~1.2 cu. ft. after displacements, the box has to be larger than I would have liked. Also, there's the added weight of the larger sub, and larger box. What I'm wondering for this scenario is, how much more powerful/louder is the 12" going to be over the 10", and how different will it sound? Is this the better option, for the sake of simplicity and sound, despite the extra weight? Oh, and this is for an 07 STi, so the trunk space is reasonable, but by no means cavernous.
