Deep, musical, in-wall subwoofer


I'm looking to build a musical subwoofer with true 20HZ extension as part of a new home theater system I'm building into my wall in the basement.

I have room for an enormous enclosure (14'x4'x3') and I have space for one or more drivers of nearly any size.

So--where do I start on a project like this? Is this a DIY? If not, who would you trust to build a custom built-in subwoofer system that can make deep bass and still be musical?
riclewis
Why limit yourself? This [url=http://curiousphotos.blogspot.com/2009/12/biggest-subwoofer-in-world.html]one[/url] will do 10 hz. Definitely a DIY job but what the hay?
I'm less interested in pre-built in-wall speakers--I'd rather find a custom speaker builder who could take advantage of the unique and large space that I have.

If I could find someone who'd be willing to build a box similar to the Wisdom S90i, but oriented horizontally, that would be ideal.

Maybe I'm hoping for a bit too much? I see custom car enclosures all the time made out of MDF, seems like it wouldn't be too hard to do the same thing in my entertainment center...
You might try

http://rythmikaudio.com/products2.html

Great products, helpful people.

Marty