I built an Adire alignment ported Shiva for fun a few weeks ago. My real sub project is a ported tempest 220L, but it is not done yet so I have playing around with this Shiva. My room is 1518 cubic feet in volume. DxWxH is 11.5X16.x5.8 Anyway I went to calibrate the sound system today using my Denon AVR3300 internal test tones (I know I sohuld be using a disk, but that is a lot more work). Anyway I set the volume on the sub to half way before calibration. I had to turn down the sub channel 3/4 of the way on the Denon to get down to 75db. Is this normal, seems like I have tonnes of power to spare? By the way I don't plan on living here for much longer so no the big Tempest won't be in this room.