Current Inexpensive sub that can get it done cheap

Thanks to all who replied so far! I did fail to define my use of "inexpensive" as was pointed out. I would say suggestions in the $1000 and less would be in my range.
This sub will be used for 2 channel music only, with the cdm7's. My room is 24 x 12 with 8 foot ceiling.

Well engineered ported designs as good as sealed designs IMHO.
Each has its tradeoffs -
Sealed boxes have issues mores on an issue with standing internal standing waves being feedback to the speaker cones. Ported designs exhibit other possible (arguably) tradeoffs. I’ve heard designs of both schools that sound excellent. All rooms exhibit ‘modes’ – they just occur at differ frequencies (they all will fall into the subwoofer range). Different speaker drivers end to work better in different designs depending on several factors. A major one is the ‘Q’ of a driver. The bottom line is that the driver needs to match the box design. One is not necessarily better than the other. Room modes and reflections also occur at all other audible frequencies. There are quite a few places on the WWW that will explain how to calculate them.

If you don't mind buying used, there is a Paradigm Servo 15a with x30 crossover for sale now that would definitely fill the bill. No association with the seller.

I would second the Paradigm Servos no matter which model.
IMHO they are exceptional for the money.