MC RO

How bass settles in a room

The room sings back

Walls give a room notes of its own. At the same frequency, bass can boom in one corner and almost vanish a few steps away.

Pick a frequency, then drag the yellow point through the room.

Red and blue mark high relative pressure in opposite phases. Yellow marks the nodes, where pressure approaches zero. The yellow point is the listening position.

(1,0,0) 40.8 Hz axial
by a node
Room dimensions
Listening position
At the yellow point 31% of the theoretical maximum · between node and maximum

Low volume. For small speakers, the selected frequency is reinforced with harmonics. Sound starts only when you press the button.

20–200 Hz

The room's score

Each line is one of the room's own frequencies between 20 and 200 Hz. When the lines bunch together, the bass becomes harder to control.

Selected mode

Where the room's notes come from

An integer number of half wavelengths fits between each pair of walls. The numbers n, m and p tell you how many fit along the room's length, width and height.

f = c/2 × √[(n/L)² + (m/W)² + (p/H)²]
Calculation, sources and limits

What the map calculates

The calculation assumes a rectangular room with rigid walls and a speed of sound of 343 m/s. At each point, relative pressure comes from the cosine functions along the three axes.

Doors, windows, furniture, materials, flexible walls, speakers and air temperature change the level and can shift the frequencies slightly. The map locates theoretical nodes and maxima. Measure the room before deciding where to put speakers or acoustic treatment.

Formula and sources checked 14 August 2026.

  1. MIT OpenCourseWareRoom acoustics & reverberationStanding waves and modes between parallel walls.
  2. University of IowaAcoustic Spectroscopy of RoomsThe three-dimensional formula for rectangular room frequencies.
  3. Purdue UniversityModes in a rectangular roomA visual example of pressure sign and amplitude.