Schroeder Frequency Calculator

The Schroeder frequency (or crossover frequency) marks the transition between the low-frequency region of a room, where individual resonant modes dominate, and the higher-frequency region, where the modes overlap so densely that the room behaves statistically as a diffuse field. Below it, room modes cause large peaks and dips; above it, the response is smoother and treatable with statistical acoustics.

In metric units, f_Schroeder = 2000 * sqrt(RT60 / V), where RT60 is the reverberation time in seconds and V is the room volume in cubic meters. The constant 2000 comes from the modal-overlap criterion of three modes per modal bandwidth. A common approximation also written as f = 2000 * sqrt(T / V).

Below the Schroeder frequency, room treatment must target specific modes with bass traps and careful speaker and listener positioning, because the response is dominated by widely spaced resonances. Above it, broadband absorption and diffusion work statistically. Knowing the crossover tells you which regime you are dealing with at a given frequency.

Yes. Because volume appears in the denominator under the square root, larger rooms have a lower Schroeder frequency, so they reach diffuse behaviour at lower frequencies and have fewer problematic isolated modes in the audible range. Small rooms, such as home studios, have a high Schroeder frequency and significant modal problems well into the bass and lower midrange.

A longer reverberation time raises the Schroeder frequency because reverberant, live rooms have narrower, more resolved modal peaks that stay distinct to higher frequencies. A deader room with shorter RT60 lowers the crossover. So adding absorption both shortens RT60 and modestly lowers the Schroeder frequency.