I got my PB10 ISD yesterday. I calibrated it using my DVE disk to 83db (Added only 8 db for DVE disk miscalibration of the subwoofer tone). The channel level on the reciever for the subwoofer is -5 and the gain control on the sub is at 12'0 clock position. My living room is where I have the HT setup with 2100 cu feet dimensions and opens out to the kitechen with 640 cu ft dimension. The sub is not in a corner bcos I was adviesd to keep it close to the listening position and my listeneing position is somewwhat at 2/3 the distance of the room. However sub has a wall behind it and the woofer faces my seating position. I get a heavy port noise when I am listening to movies with bass intensive scenes @ -10 to -15 db refernce volume. The woofer is not bottoming out but the port noise is really bad. I switched off the sub now and I will wait for an answer from you guys cos I am afraid I might damage it or something cos I read a couple of guys had blown up their PB10 ISD. Here is the list of movies I found the port noise. 1. U571 - The Depth Charge Scene. 2. Master and Commander - Some cannon shot scenes. 3. Matrix Reloaded. The higwway chase scene when one of the agents jumps out of his car and onto the car of Morpheus.