Here's my dilemma: I purchased an M&K S-150 THX 5.1 system in September, which came complete with a reference-standard THX MX-150 MKII 150 watt powered subwoofer, FR 20 Hz - 200 Hz, selectable low pass filters, push-pull dual 12" long-throw drivers, magnetically shielded. Ok. So I own it. It's mine. Done deal. Now my a/v installers are strongly recommending that I locate my sub in the attic over my home theater room, which is 25' X 19' with 10' ceilings. First, this sub typically sits on a solid floor. If I let them put it in the attic, they plan to vent to the room through a grilled opening of some sort. Would the sub stand on or above this grill in the same way it would have in the room or would it be placed face down so the front of the sub would be directed through the grill into the room? Second, should I just store the sub somewhere and build an infinite baffle? I have no experience with them, but from what I've read on the Cult website, they seem to be ideal for attic installations. I guess an extension of that idea would be whether to cannibalize the M&K sub to make an infinite baffle...? Thanks in advance!