Room mode calculator
Enter your room's dimensions and see where its resonances land — which frequencies pile up, and which are left unsupported.
How to read this
A room resonates at frequencies whose half-wavelengths fit its dimensions. f = (c/2)·√((nx/L)² + (ny/W)² + (nz/H)²), with the speed of sound taken as 343 m/s at roughly 20 °C. One non-zero index gives an axial mode — a bounce between one pair of surfaces, and the strongest of the three. Two gives a tangential mode, around four surfaces, roughly 3 dB weaker. Three gives an oblique mode, involving all six and weaker again.
What matters is not any single mode but their spacing. Modes bunched within a few hertz reinforce each other and produce a note the room plays whatever you feed it — the frequency that booms in one corner and disappears two steps away. A gap of 25 Hz or more leaves a band the room does not support, so bass written there feels absent even when the meter says it is present. Even spacing is the goal; that is what the good room-ratio tables are chasing.
Above the Schroeder frequency, modes crowd together densely enough to behave statistically rather than individually, and the room stops being a set of resonances and starts being a reverberant field. Below it, you are hearing geometry.
What this cannot tell you. The maths assumes a sealed, empty, rectangular box with rigid walls. Your room has a door, a window, a desk, furniture, and probably a wall that is not quite parallel — all of which shift, damp and smear these predictions. Treat the output as where to start listening and measuring, never as a diagnosis. A measurement microphone will tell you what your room actually does; this tells you what to expect it to do.