TC,
Try physically setting the sub in the "Sweet Spot". Then play a DVD or CD with a recognizable bass segment on repeat. The Menu for "Lost in Space" or "Godzilla" do a good job. As the DVD or CD plays, literally crawl around the perimeter of the room, even back near the stairwell, etc...and listen for the most bass. You will probably find more than one spot. The one with the best bass will be where you would "want" to put the sub provided the room or furniture will allow...that is why you keep track of the other locations...you may have to settle for the second best spot or third...may also consider re-arranging the furniture...
When you have found the spot, put the sub there and re-calibrate...
An additional observation: I had one of the SVS tubes as well but my room was 13 X 18 and I was told by Tom at SVS that the 20-39 PC Plus would be the best for my room...your room looks a bit bigger than mine and so you may need more sub...A call to SVS may also help to figure out if you need more...they will not attempt to oversell you...similar customer service to Axiom...
My 20-39 PC Plus would rattle doors and knock figurines off the walls with the gain only up about a quarter...not to mention scare my son and his friends with the T-Rex fight against the Spinosaurus in Jurassic Park III.
Talk to SVS...
Hope this helps.
WhatFurrer
PS: I now own an SVS PB 12/2 Plus.
