Room Mode Calculator

Knowledge Base

What Are Room Modes?

Every rectangular room resonates at specific frequencies determined by its dimensions. The same way a guitar string resonates at a frequency set by its length. These resonances, called room modes, boost some bass frequencies and cancel others depending on where you stand or sit in the room.

Axial, Tangential, and Oblique Modes

Axial modes (calculated here) run between two opposite parallel surfaces (floor/ceiling, or the two side walls) and are the strongest and most audible. Tangential modes involve four surfaces and oblique modes involve all six. Both are weaker and left out of this simplified calculator, which focuses on the modes worth treating first.

Reading the Clash Warnings

When two axial modes land within about 5 Hz of each other, their effect compounds. That frequency gets significantly louder at certain listening positions and significantly quieter at others. Rooms with a length, width, and height that are simple multiples of each other (e.g. a perfect cube) have the worst clustering. Rooms with dimensions in a more irregular ratio spread their modes out more evenly.

What To Do About Problem Frequencies

Bass traps in room corners (where all three axial modes overlap in pressure) are the most effective single treatment. Moving your mix position and speakers away from the exact 1/2 or 1/3 points of the room length also helps avoid sitting in a null or peak. This calculator tells you where the problems are. The Reverb Room Estimator tells you how much absorption you need to add.