Home Theater Acoustics

Room acoustics have become the bottleneck for quality home theater sound. Every other part of a home theater has dramatically improved in recent years.  Inadequate room acoustics will spoil the sound of even the finest audio system.

Proper home theater acoustical treatment addresses:

• Reverberation - Today's surround sound motion picture soundtracks have the reverberation carefully accounted for during the sound mix. Too much reverb ("liveness"), and your sound has low fidelity compared to the original soundtrack. Worse, excessive reverberation reduces dialog intelligibility, so you can't hear every word clearly.
  

• Early Reflections - Also called "first reflections," these come from mirror points on your walls and ceiling, which create a addtional virtual sound sources. When these reflections are heard within around 15 milliseconds of the original sound, the ear combines the sounds into one. This smears out the front sound stage, and result in poor imaging and localization.

• Diffusion - Diffusion causes sounds to uniformly bounce around the room. Some of it is good, resulting in realistic surround sound. The surround sound channels should not be precisely localizable, unlike the front left, center, and front right channels. These front channels are designed to eminate from the screen. The surround channels create an ambiance that puts you in the center of the movie. Not only does diffusion make surround sound better, it evens out the reverberation in your room, making sounds decay cleanly and uniformly.

• Certification - How do you know that your home theater has good acoustics? Acousticians have developed very effective measurement techniques over the years. Professional standards have emerged, and these have been applied to commercial cinemas. We have scaled these for the home theater, and have created the Alpha Certification^SM program. When your home theater is Alpha Certified, it is guaranteed to conform to the highest standards of cinema acoustics. You can be confident that films you play at home will sound just like they do in the best commercial movie houses.

What about the other home theater certifications - THX™ and ISF™?

THX is a certification for home theater audio equipment, and ISF is for picture quality. Neither cover room acoustics. These standards are complimentary to Alpha Certification, and we support both. While THX recently added a room certification program, they require you to hire them to build the room. Furthermore, their standards are not as strict as ours, and many THX rooms would fail Alpha Certification.

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