My room is around 20ft by 50ft open to another room that's close to the same size, the trim level is set to flat the sub is set at the 7 o'clock position, my setups at an angle in the left corner of the room and I think that's resulting in much of the boom. The meter is having no problem getting my speakers to 75db. I'm using the test tones on the 3805 and that automatically sets the receiver at 0db.
I tried what you did in walking with the meter and I got some pretty varied results, from my listening position and moving back almost thirty feet the SPL level stayed at about 65db (That's about as high as I could stand to crank it up)as I moved towards the left wall the db's started going up, when I got within 2 feet of the sub in the left corner the db's jumped to 80.
I'm starting to think my sub location is most likely the problem. Since the sub is in the corner in the left and the entire right side of the room is open that may be affecting the sound. I'm wondering if maybe some bass traps might help out. I did move the sub away from the side and back walls a few inches and that seemed to help, but I've still got the sub set at 7 o'clock and 3.5 db on my receiver to get to 65db in my listening spot.
