Start

Room Modes (Standing Waves)

Natural acoustic standing waves formed by sound reflecting between parallel room boundaries.

By roomtreatment.diy editorial team ·

Room modes are acoustic standing waves that occur in enclosed spaces when sound wavelengths match room dimensions. Speed of sound (343 m/s) divided by twice a room length establishes fundamental mode frequencies where bass peaks (+12 dB) and nulls (-24 dB) occur.

The formula

fnx,ny,nz=c2nx2Lx2+ny2Ly2+nz2Lz2f_{n_x, n_y, n_z} = \frac{c}{2} \sqrt{\frac{n_x^2}{L_x^2} + \frac{n_y^2}{L_y^2} + \frac{n_z^2}{L_z^2}}

How it works

In rectangular rooms, axial room modes carry the most energy because sound bounces directly between two parallel walls. Treating room modes requires placing thick porous bass traps in corners where acoustic pressure accumulates.

Work it out for your room

Put in your own room's size and get the numbers for it, free and without an account.

Open the Room Mode Calculator

References

  1. Kuttruff, H. (2016). Room Acoustics (6th ed.)
  2. Everest, F. A. & Pohlmann, K. C. (2015). Master Handbook of Acoustics (6th ed.)

See this in your own room: draw it, place speakers and treatment, and simulate the result.

Model your room in 3D