Make Your Point: Strategies for Home Theater Sound Reflection

Sound control strategies for home theaters can be complicated if the individual methods themselves are not fully understood. Along with absorptive material and corner panel placement comes the need to appreciate the effect of reflection points for top quality sound control in home theater systems.

Sound absorption in home theaters often follows common sound absorption strategies. Many times home theater owners choose to focus their sound absorption attention on strategies that include basically involved the lower half of the wall. Perhaps a chair rail is installed to divide the upper and lower halves of the wall, limiting sound absorption to the lower half, restricting sound absorption to ear level and below. The ideal location for installing sound absorbers is on reflection points. Imagine a little gnome sitting on top of your speaker with a hand full of rubber balls. The spot on the left side at which you have to bounce that ball to hit you in the left ear is the perfect place to put an absorber. Although above the chair rail level, the panel will control early reflections. The same principle is true of the first reflection points of the ceiling, the right wall, and perhaps even behind the primary seating area. The best places for panel placement are corners in a diagonal mounting to control low frequency and the first reflection points off your side walls and ceiling.

To find your first reflection points, there is a way to figure them out using a mirror. While remaining seated in the primary listening/viewing area, have someone hold a mirror flat to the wall and move it around. The reflection point is established when the speaker is visible in the mirror. However, as most people who ever played pool, or billiards, already know, reflection points are easily discernable with the naked eye. For example, if you are sitting in your home theater and you want to bounce a red rubber ball off the left wall and hit your speaker, determine where you would throw the ball to determine the reflection point. Yet another concern of home theater owners is whether or not to add sound absorption to front speakers. By adding absorption to front speakers, the sound that is heard when facing the front of the room will be from the speakers and not from any reflections off the front wall, making the speakers sound more precise.

For additional early reflections points, a panel should be installed behind each speaker with a third hung in the middle. The closer the listener is to the wall, the closer the first reflection point is to your speaker. For sound absorption directly behind the primary seating area, the closer the listener is to a wall the more the home theater space will benefit from rear-hung panels. The secret is to not overtreat the room. Remove the least amount of objects necessary for a clear, precise sound and leave all other surfaces bare for some echo and reverberation. Finally, when sound treating smaller rooms, it is recommended to use the thickest panel possible. If there is simply not enough room for the thickest panel on the market, a thinner panel is the most practical. Aside from the acoustics, the overall goal is to furnish the available space to be comfortable and aesthetically pleasing.

Home theater acoustic rules are made to be broken. Although thicker panels are naturally better because of better low frequency absorption, they may not always be the most reasonable for the available space. When possible, it is recommended for home theater owners to use thicker sound-absorbing panels. There is a perceivable benefit for the listener and the overall cost is negligible.