Room Mode Calculator
Which bass frequencies will your room amplify?
Enter your room dimensions to calculate axial, tangential, and oblique room modes, spot problem frequencies, and compare against ideal room ratios.
How it works
The math behind the answer
Below a few hundred hertz, a room stops behaving like open air and starts behaving like a resonator. Sound waves bounce between parallel walls and reinforce themselves at specific frequencies called room modes. At those frequencies some seats get booming bass and others get almost none.
The strongest modes are axial: they form between one pair of surfaces, at frequencies of n × c / 2d, where c is the speed of sound and d is the room dimension. Tangential and oblique modes involve two or three pairs of surfaces and are progressively weaker.
This calculator lists every mode below 300 Hz, plots them, flags stacked and unevenly spaced modes, and compares your room's proportions to classic 'good' ratios. It also estimates the Schroeder frequency, above which modes are dense enough to stop mattering individually.
Common questions
- What are the worst room dimensions for bass?
- Cubes and rooms where one dimension is a whole-number multiple of another. A 16 × 8 × 8 foot room stacks modes on the same frequencies, producing severe peaks and nulls.
- Can EQ fix room modes?
- EQ can reduce peaks. It cannot fill nulls, because a null is a cancellation and adding more energy just cancels more. Treatment, placement, and multiple subwoofers handle nulls.
- What is a good room ratio?
- Several published ratios avoid stacking modes, for example 1 : 1.4 : 1.9 or 1 : 1.6 : 2.33 (height : width : length). The calculator tells you which classic ratio your room is closest to.