Originally Posted by Rob100
Ceiling height is approx 7' 6". Not quite sure what you mean by "you'll potentially have a monster pair of combining room modes at 45-55Hz. These will dominate the sound of the sub, masking the lower frequency output." If you could elaborate I would be very grateful.
Are you saying that a BFD will enable me to overcome the problem described above?
Subwoofers are cable of exciting the rooms natural resonances. These are directly related to the room dimensions as the standing waves (room booms) are only present at the frequencies with wavelengths related to the rooms dimensions.
Measure your room and plug the measurements into this
. This will indicate the frequencies most likely to 'boom' in your room.
When I saw that you had a 9ft room width, I realised that it was close to the probable floor to ceiling dimension, circa 8ft. This will likely result in two booms (more correctly, modes) that will cause peaks in your subs response. That they are so close together means that they will combine, to a certain degree and cause a massive boost at across those frequencies.
Even with your current setup, if you wander around the room, you'll note that bass is massively louder the closer you get to a wall. Try it. If you get a quality sub, position it against the front wall and then sit against the rear, believe me you'll suffer some astonishing bass, especially at the frequencies the rooms dimensions favour. The gain in the subs frequencies affected by the rooms dimensions are at their most extreme at the room's boundaries and that's wher you're going to sit AND position the sub.
The fact is, your hearing reduces in sensitivity with reducing frequency. Therefore, if you have a really dominant frequency in the room(which you will with the current arrangement), it will tend to overpower lower frequencies. In other words, you'll reduce the volume of the sub so it doesn't sound overblown, but in so doing, you'll be turning down the frequencies you bought the big sub for in the first place.
Buying a BFD/SMS-1 allows you to tune out the dominant peaks in the subs in room response. In your case, this is even more critical because of the sub/seating positions. Once these peaks are gone, you'll find that you turn the sub up to actually hear all of the subs output on an even footing, et voila! Your deep response becomes noticable.
Along the way, you'll note that the sub sounds tighter, cleaner and faster. It involves some effort, but unlike the main speakers, it's easily measurable with any number of freely available on-line resources, which simplifies the process. Doesn't make it any less adictive though.