The point of purchasing a new audio system is to hear the music or movie exactly the way it was recorded without the typical distortions that are added by the room in which the system is set up. By following a few basic steps, you can largely eliminate room acoustic effects and get the pure sound that you wanted when you bought your new audio equipment.

When you’re outfitting a new home theater room, or installing your stereo equipment, pay particular attention to the directions for loudspeaker placement. If the manufacturer is thorough, they’ll say something like “do no place speakers midway between the floor and ceiling.”  The floor and ceiling will reflect the sound waves from the speaker back down into the room. If these two surfaces are equidistant from the loudspeaker, then when the two waves meet, then they should be mirror images of each other. In other words, they’ll be at the same point in their wave, but out of phase by 180 degrees. This results in acoustic cancellation as each wave tries to negate the other. By changing the distance so that the speaker is either closer to the ceiling or to the floor, then when the waves meet, they’ll be at different points in their peak to valley wave-form. The cancellation will be greatly reduced.

The same effect can happen when sound waves reflect off the side walls in the room as well. In this case, it isn’t always possible to cure the problem with speaker placement. Adding some acoustic treatment panels to the walls, however, can break up and reduce the reflections to lessen their interaction with one another. Materials like Owens Corning 703 can be used for this purpose. Covering the acoustic panels with cloth that matches the décor of the room, can help them not only blend in, but add some visual character to the room as well.

Bass tones present particular problem for most homes because each wave can be as much as 50 feet or more in length. This is almost always bigger than the room, in at least one dimension, length, width or height. As a result, a single bass sound wave can be folded back upon itself resulting in a stationary or standing wave. When this happens, the level of perceived bass is alternately greatly boosted or largely cancelled depending upon where in the wave the listener is positioned. This throws the tonal balance of the music or movie audio out of balance, making it seem unnatural. The solution to this problem is to attack areas of the room where bass gets multiplied by reflections, specifically, the room corners. The installation of corner bass traps can help restore the correct balance between bass and treble frequencies.

Room acoustic treatments such as acoustic wall panels and bass traps need not be very expensive, but they can make a huge difference in the quality of the sound that you get from your expensive electronics.