Car Stereos: speaker box, inch speakers, power competition

Question
hi there. I have a pair of q-power competition 15 inch speakers, with a 4000wt. single ohm amp, pushing them. I know the box that they r in is def. to small, thus i am going to build a new one for them, but before i do, i need to find out the proper dimensions that i need to build the box, for maximum performance. How much room does each speaker need  from top to bottom, and side to side, in its area inside the box. I would also be more then appreciative for any other tips towards the construction of this box, including what would be the best wood to use for it. Thankyou in advance if u r able to provide any feedback on this. And thank you n e way even if u arent. U guys have walked me all the way through my systems so many times, and now im in bass comps and winning trophys thanks to you guys, ya'll r great.


Answer
Hi Justin,

The space needed for your subwoofers can be found in their manual/online specifications page.  Every subwoofer requires different airspace.

What also matters is the type of build you're going with.  You usually need less space in a sealed environment vs ported.

You can generally build your boxes out of MDF.   The biggest advice I can give is: A) make sure you seal it up really really well.  Get black silicone and seal all the gaps.  They should be air tight.  And B) make sure each sub has its own air space.  You can put them in the same box, but seal each subwoofer from the other.

Justin