Most of Saturday and part of Sunday were spent installing my new IB subwoofer. The manifold is built out of .75" MDF with 2X4 reinforcing around the opening. Overall the cabinet dimensions are 9.5" x 18" x 24" (WxHxD). The opening netted out to 8" x 16.5". I used 2 of the Parts Express 15" IB subs (SKU# 295-455) mounted to either side of the manifold. It is currently being driven by 2 channels of my Marantz MM9000 (150w @ 8ohm) with one channel per speaker. There's a single cable running from my Outlaw 950 sub-out connection into a "Y" cable connected to the amp. The sub is mounted VERY solidly in the attic directly above my entertainment center. The bottom of the opening ended up just a bit over 8' off the floor and about 6" off center of the entertainment center (damn vent pipe!). The opening into the living room is covered by a grill assembly built out of MDF and covered with white grill cloth also from PE. The SO dyed the cloth with tea(??) and got the color match with the wall dead on. Go figure... I'd have never thought of that... The sound is nothing short of amazing. Even though it only has a few hours of music played on it and probably still needs a good bit of "break-in" I sat and listened in utter amazement. I had no idea that music could sound like this in my house. There is a VAST improvement in definition. I'm hearing detailed bass runs that where always sort of a "low frequency blur" before. I had been using a JBL S120PII sub up until now. It's a nice sub but it's not even in the same league as the IB. I don't really know all of the proper "audiophile" words to describe what I'm hearing. All I know is that I just LOVE the way it sounds. The bass is blended into the music in a way that I've never really heard before. The real musical test came from playing Josh Groban's Jesu, Joy Of Man's Desiring (track 12). There's a whole lot of VERY low pipe organ in that cut. The JBL did a nice job with it in the past but the IB plays it SOOOO much better. Like I said in the subject line... STUNNED! I've not yet watched a movie but I'm thinking that LOTR is probably the best work out I can give it. What's next??? A more suitable amp, though even at near painful SPL's the MM9000's clipping lights never light up. Perhaps something along the lines of a BFD to smooth out the room response. The bottom line... If you have the means to put in an IB-sub, that means the space as well as the $$$, just do it. Don't hesitate! Get started on it TODAY.