I'm upgrading a theater room from floor standing spkrs to all in-wall. Aesthetics and space constraints make in-walls necessary - no cabinetry, nothing on the floor.

I'm looking at the Velodyne Sub-Contractor In-Wall with designer grill. [Link: velodyne.com]
It has a very low profile grill - only about 5" X 17". I'm replacing a conventional powered sub - don't know the model but it's big, looks like a 12". I have no experience with the Velodyne in-wall but I can't see it moving as much air as a 12" in a large box. Anyone installed one and can give some opinion?

Any other options for an in-wall that doesn't show a huge grill? I'd love to use a powerpipe but there's nowhere to put the box towards the front of the room. My other option is a standard sub vented through the rear wall but I'd prefer to keep the sub in the front of the room.