Down firing sub

I am setting up a HT and 2-channel system in our new house. The room is circular and the only plave I can put a sub is in a built in alcove in the wall by the TV. My wife will not allow it in the room and there is no way to run the wires. I can make the built in "niche" as large as I need it. I am looking for a sub that will give me good HT and 2-channnel music. I assume I need a front firing sub. What would be best? The Velodyne is front firing but the REL is downfiring. What do I need to do to the enclosure to isolate it. Anyone with experience with this? Your help is greatly appreciated.

The REL Q series are front firing, Q100E, Q201E, etc.
I use a Linn AV 5150 which is downfiring but the manual clearly shows how to pull off the stand and mount it to be front firing (i.e. in and enclosure/stand/or the 'little niche' your wife will allow.)

It's an interesting question, given that you can make the space for the sub any size, assumably any shape as well, you should be able to use any sub, given the shape of the space is good. You'll need to figure out how to properly shape the space, but, once this is right, you probably could use any sub you like!

This thread just reinforces how great single life is to me! My girlfriend only asks wonderful questions like do they (new speakers/amps/etc) make you happy?

Good luck, you've got your work cut out for you figuring out the best shape and size alcove to make!
I would recommned you contact and check out the leviathan sub kit they make. It is the best sub that I have ever heard. It is designed to be down firing.
I am currently using two of these. The power and quality of the sound has few if any equals.