Room Mode
Low-frequency standing waves set by room dimensions, creating uneven bass
Related
Room modes are standing waves formed by reflections between room surfaces, boosting or cancelling particular frequencies at fixed positions. Axial modes involve one pair of parallel walls, at roughly the speed of sound divided by twice the distance; tangential and oblique modes involve more surfaces.
Low frequencies have long wavelengths, so small rooms space their modes widely, booming on one note and disappearing at another seat. Room proportions, speaker placement and listening position all affect how strongly modes are excited. Bass traps and measurements at several points work better than blind equalisation.
The usual mistake is assuming only large rooms have modes. Every enclosed space does, though the frequencies and density differ; small rooms often show the problem more plainly and are harder to escape by moving speakers alone.
Sources
- 房间模式与低频驻波，参 Everest & Pohlmann, Master Handbook of Acoustics 与 Philip Newell, Recording Studio Design；本文为原创表述
Used for fact-checking only; all prose is original.