Larger reflection-free listening volumes require proportionally larger absorption patches

Evidence

One advantage of this technique is that it also shows places where absorption is unnecessary. This is useful because it shows you where to place doors and windows that are difficult to make absorptive. To minimize the amount of absorption needed, one should make the listening area as small as possible, because larger reflection-free volumes require larger absorption patches. The method is equally applicable in the vertical as well as the horizontal direction. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 2300

Categorization

• SEED: ‘The image-room method also tells you where you DON’T need absorption’ is a counterintuitive angle for a practical listening-room piece.