Need more bass! Or as a Mexican band stated in our studio years ago, “we need more boomba’ boomba.” This type of question is rather common: “I have a pair of the Tannoy PB8’s in my studio. They’re positioned just behind my Mackie 8-bus console on 42″ stands and are about 12″ away from the front wall of the studio and perhaps 60″ away from the sidewalls. The distance to the other end of the room is approximately 12 feet. My problem is that the speakers are not reproducing the low end so that my mixes tend to be bottom heavy when I take them to another system. It’s not a speaker problem. I’m sure it’s a room problem. Do you have any suggestions as to what I can do to get a more accurate bass picture?”
Chances are your speakers are putting plenty of bass energy into the room. If not, a good powered sub will quickly take care of that. The problem is likely that your listening position is in a null. Basically bass is being canceled there. This is very common with small rectangular rooms. One problem is that the volume of the room is too small for real low frequency waveforms to properly develop. The bigger problem is that all of the parallel surfaces produce standing waves, many of which happen to be canceling each other at your listening position near the middle of the room. If you were sitting in a chair in the back of the room you would probably be hearing too much bass. Assuming you can’t change the size, shape, or configuration of the room your next best choice, believe it or not, is to try to trap (absorb) some of the bass energy where it is strongest. This is what people use bass traps for. They typically are set up in corners and other areas where bass often accumulates. By trapping some of the energy that is coming back to cancel itself you will actually get more bass, and certainly more accurate bass that is more in phase with the rest of what you are hearing.
You might want to check out our on-line white paper from RPG, which includes information about bass traps. Our sales staff and RPG themselves can give you further info about what you need to solve this problem. Our recent Acoustics Summit entries have some helpful acoustical hints as well.