March 2013: The Perfect Pi(e)

Happy Pi Day (3.14)! In February’s newsletter, we discussed different types of theatrical sound systems and the pros and cons of each. This month, we explore the properties of good room acoustics. Read on to learn more about interior room acoustic considerations for theaters.

Have you ever attended a live indoor performance and struggled to hear the dialog or found the music to sound distorted? Some might attribute it to a poorly performing sound reinforcement system. Others might find fault with the room acoustics. The truth is a great aural experience requires careful consideration of both the sound system and the room acoustics. The recipe for good room acoustics calls for three main ingredients: room volume, surface finishes, and room shape.

Room volume and surface finishes are related to a space’s reverberation time, which is the time it takes for sound to decay by 60 decibels. As the room volume increases, so does the reverberation time. Inversely, the reverberation time decreases with more absorption in a room.

Ware Center for the Fine Arts, Lincoln University (Photo credit: AP3C Architects)
Marion Anderson Music Center, Cheyney University (Photo credit: KEARNEYDesign, LLC)

Theaters with too much volume and too little absorption yield high reverberation times, which can lead to poor speech intelligibility. On the other hand, theaters with too little volume or too much absorption can produce a harsh or flat sound – both limiting the enjoyment of music. A balance of room volume and absorptive surface finishes is the key to achieving the right mix of direct and reverberant sound. The ideal room volume can be determined based on the program content and the size of the audience.



Room shape affects the direction and arrival times of reflected sound energy to the audience. In the best theaters, the audience hears sound from all directions as it reflects off of wall and ceiling surfaces and is diffused across the room. This desirable acoustic environment leads to a sense of envelopment.





As any cook knows, following a recipe is no guarantee for success. The ingredients must be blended in the right way to produce the desired result. Acoustics is no different. Through careful combination and consideration of the room size, finishes and shape, the room acoustics can produce an award-winning acoustical pi(e) and theater experience.

April 2013: Smoke and Mirrors
February 2013: Some Heartfelt Sound Advice