Home Theater Diffusion and Reflection: Pairing Up Plates and Panels for Superb Sound

Creating the perfect sound in any home theater is a challenge to say the least. Many homeowners are searching for the panacea that will alleviate any and all reflection and absorption problems. By combining treatment options, sounds at all frequencies may be successfully managed, generating a professional sound at an amateur price.
• Frame it up. Commercially marketed bass trap frames and plates can be a tricky proposition for those who are limited in both expense and knowledge. To reduce confusion, home theater owners should be aware of the existence of steel-framed bass traps and corresponding plates for maximizing diffusion. The advantages of the available steel-framed bass traps and plates include:
o With steel frames, the home theater owner is able to either purchase corresponding fabric bags or create fashion bags using fabrics that complement the room’s décor.
o The steel frame provides a ridged means to hang panels from the ceiling or the walls
o Newly available bass trap include those made of a fire rated plastic material that is heavy enough that it does not resonate. The plates are also equipped with tabs and grooves, enabling them to be snapped directly into acoustic frames.
Frames and plates, when properly paired, create rigid units that do not resonate, regardless of the sound field, resulting in the desired diffusive reflection.

• Property values. One concern some home theater owners may have is the inhibition of bass trap properties. The diffusion is able to achieve the following without compromising bass trap function:
o Reflection improved at higher frequencies.
o Absorption reduced at higher frequencies.
o Effort retained at lower frequencies.
Diffusion of waves below about 300-400 hertz would be negligible. Below 350 hertz, the diffusion plate would more likely be considered an absorber.

• Flying high again. There is a common problem with sound treatments that involve the complete elimination of high end reverberations. Contents of a dedicated theater space include carpeting and drapes that absorptive on higher frequencies but not low frequencies. In order to have a sound balance, try the following:
- Control the lows. Broadband absorptive materials help to control the low frequencies not addressed by other treatments, e.g. corner panels and 4-inch panels on the walls and ceiling.
- Reflect the highs. Bass trap plates improve reflection of the higher frequencies in a diffusive way. Now when the sound hits it the sound gets spread over a wide 120 degree arc.
By adding plates to bass traps, high frequency reverberation is returned to the room as it diminishes the amount of absorption taking place.
Battling reflection, absorption, and diffusion challenges can be mentally taxing and can send some home theater owners digging in their wallets for a high-end solution for a low-end problem. Although sound is a priority in home theaters, solutions are available that not only create the desired result but also let the homeowner keep a little in his wallet for the next big home theater discovery.