Primacoustic - Acoustical Solutions

Just like commercial movie theatres, home theaters suffer from acoustical interference caused by reflected sound waves. One type of reflected sound that is particularly destructive to dialog intelligibility is early reflections, also known as primary reflections. To solve the issue in commercial movie theatres the walls and ceiling are treated with sound-absorbing fabric-covered panels.

Primacoustic Broadway allows you to treat surfaces in your home theater in the same fashion as commercial theaters do, with fabric covered acoustic decor panels.

What are Early Reflections?
Early reflections are sound waves that bounce off one room surface, such as a wall, ceiling or floor before arriving at the listening position. Early reflections are slightly delayed compared to direct sound waves because they travel a longer path. Early reflections can be beneficial by defining the width of the stereo image.

However, in room with hard and reflective side walls, the early reflections can be close to or equal to the amplitude (loudness) of the direct sound waves and that can be destructive to dialog intelligibility. Controlling early reflections in the mid and treble frequencies is the first order of business for the application of acoustic treatment in a home theater.

How to control Early Reflections? The vocal range frequencies are quite directional and behave much like light waves bouncing off a mirror in that the angle of reflection is equal to the angle incident. This means you can use a mirror to establish the ideal locations for Broadway panels.

While seated in the listening position, have an assistant simply move a mirror along the side walls until you can see a front speaker in the mirror. Mark the wall in each location where you can see one of the three front speakers. These marks represent where the centers of Broadway panels will be placed to absorb the acoustic energy that would otherwise be reflected directly to the listening position.

A room with too much absorption will sound dead and lifeless from a lack of reflections. The best way to avoid over treating is by allowing for some reflective wall space between Broadway panels. This will ensure your side walls have a balance between absorbent and reflective surfaces that will provide some early reflections without compromising intelligibility.

Broadway panels come in four sizes and three thicknesses to help fit your application. For typical sized listening rooms spaced 12" x 48" Broadway panels are the right scale for side wall treatment. For larger rooms consider using 24" x 48" panels. If furniture is going to be placed along the side walls consider the 24" x 24" Control Cubes.

What panel depth to improve dialog intelligibility?

Consider the fundamental frequency bandwidth of the vocal range; it starts around 100Hz for baritone and goes as high as 2.25kHz for soprano.

Test results show 1" thick Broadway panels are 100% absorbing at 1kHz and up while the 2" and 3" panels are effective starting at 300Hz.

For this reason we recommend two and three inch Broadway panels for controlling frequencies across the entire vocal range for perfectly clear, understandable dialog.



	Back To Last Page Controlling Early Reflections The good and the bad news about room acoustics Reflections, like waves in a pond Modal Resonance, different frequencies, different problems GREEN= Direct sound from loudspeakers. RED= Early (primary) reflections from close walls can be equal in volume to the direct sound. Slight time delay from traveling a longer path create comb filtering effects in the listening position. BLUE= Secondary reflections can create short but distinctive echoes. Flutter echoes are reflections between parallel walls. Chatter echoes are reflections that bounce around in corners before being returned to the listening area. Secondary reflections seem to ring on after sound from the loudspeakers has stopped. The listener experiences a ratio mix of direct to reflected sound. If the reflections are too powerful the loudspeaker sounds distant and indistinct in the vocal bandwidth. A mirror can revel the vectors early reflections travel and help you located acoustic absorption where it will work best. Acoustic treatment cuts down the level of early reflections and provides a better ratio of direct sound. Gaps of reflective wall space between acoustic panels allow for some beneficial reflections. Just like commercial movie theatres, home theaters suffer from acoustical interference caused by reflected sound waves. One type of reflected sound that is particularly destructive to dialog intelligibility is early reflections, also known as primary reflections. To solve the issue in commercial movie theatres the walls and ceiling are treated with sound-absorbing fabric-covered panels. Primacoustic Broadway allows you to treat surfaces in your home theater in the same fashion as commercial theaters do, with fabric covered acoustic decor panels. What are Early Reflections? Early reflections are sound waves that bounce off one room surface, such as a wall, ceiling or floor before arriving at the listening position. Early reflections are slightly delayed compared to direct sound waves because they travel a longer path. Early reflections can be beneficial by defining the width of the stereo image. However, in room with hard and reflective side walls, the early reflections can be close to or equal to the amplitude (loudness) of the direct sound waves and that can be destructive to dialog intelligibility. Controlling early reflections in the mid and treble frequencies is the first order of business for the application of acoustic treatment in a home theater. How to control Early Reflections? The vocal range frequencies are quite directional and behave much like light waves bouncing off a mirror in that the angle of reflection is equal to the angle incident. This means you can use a mirror to establish the ideal locations for Broadway panels. While seated in the listening position, have an assistant simply move a mirror along the side walls until you can see a front speaker in the mirror. Mark the wall in each location where you can see one of the three front speakers. These marks represent where the centers of Broadway panels will be placed to absorb the acoustic energy that would otherwise be reflected directly to the listening position. A room with too much absorption will sound dead and lifeless from a lack of reflections. The best way to avoid over treating is by allowing for some reflective wall space between Broadway panels. This will ensure your side walls have a balance between absorbent and reflective surfaces that will provide some early reflections without compromising intelligibility. Broadway panels come in four sizes and three thicknesses to help fit your application. For typical sized listening rooms spaced 12" x 48" Broadway panels are the right scale for side wall treatment. For larger rooms consider using 24" x 48" panels. If furniture is going to be placed along the side walls consider the 24" x 24" Control Cubes. What panel depth to improve dialog intelligibility? Consider the fundamental frequency bandwidth of the vocal range; it starts around 100Hz for baritone and goes as high as 2.25kHz for soprano. Test results show 1" thick Broadway panels are 100% absorbing at 1kHz and up while the 2" and 3" panels are effective starting at 300Hz. For this reason we recommend two and three inch Broadway panels for controlling frequencies across the entire vocal range for perfectly clear, understandable dialog.

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