2006 & UP BMW 3 Series Sedan or Coupe ( E90 E92 ) Subwoofer Enclosure w/ amp mou Something like this would be more practical. Looks like they will work with you to get the cubic feet the sub requires. Someone who is building an enclosure and not paying attention to the specs the sub requires doesn't know their *** from a hole in the ground. It doesn't matter how good anyone says he is. If he was going to make you one for a 15 with that small of volume, personally I would steer clear of him. The one above will give you a lot more choices in subs to run 700 into two 10s or 12s as well. If you are looking for sq
DIYCable.com : Intro » Home » Exodus Subwoofers » The extra one can be purchased for the savings of the box. Or you could possibly email them (enclosure manufacturer) and see about a single 15 even though they only list a single 10 or 12 as well as dual for both on their options. 2 12s have more cone area than a single 15 so if all else is the same 2 12s are louder. If it is too much spl the gain can be blended to match the rest of the system. A single shiva is plenty for sq. If you want sql go with two. I don't know if you are running factory speakers or not, if so they will not be able to keep up with 2 shivas. Food for thought if you do not have the cash for comps and amps. You will need about 40-65 rms to comps to blend the shiva in at 700 rms. And about 75-125 depending on efficiency of comps to blend in 2 shivas for a balanced sound.Good luck.