Chapter 5 - Small Room Acoustics

Abstract

It is possible that there is no area in professional audio where there is more confusion, folklore, and just plain misinformation than in the area of acoustical treatment. Everyone, it seems, is an acoustical expert. Of course, like most disciplines, much of acoustics is logical and intuitive if one understands the fundamentals. As Don Davis wrote, “In audio and acoustics the fundamentals are not difficult; the physics are.”1 The most fundamental of all rules in acoustics is that nothing is large or small. Everything is large or small relative to the wavelength of the sound under consideration. This is one of the realities that makes the greater field of audio so fascinating. Human ears respond to a range of wavelengths covering approximately 10 octaves, as compared to eyes, which respond to a range of frequencies spanning about one octave. Even though the bandwidth of visible light is obviously much larger than that of audible sound because of the much higher frequencies involved, the range of the wavelengths in this 10 octave bandwidth poses some unique challenges to the acoustician. We must be able to deal with sounds whose wavelengths are 17 m (56 ft) and sounds whose wavelengths are 1.7 cm (0.6 in).