Room modes are a collection of frequencies that exist in a room caused by a sound source like a subwoofer or loudspeaker. Those modal frequencies are directly related to the room dimensions.
A room mode can cause both peaks and dips in frequency response. When two or more waves meet with reflections off the walls, floor, and ceiling and are in phase with each other at a specific frequency, you will have a peak in response. When they meet and are out of phase with each other, they cancel and you end up with a dip or null in response. These "modal resonances" store energy and decay, causing audible problems such as "one-note bass" and "boominess," even robbing mid and high frequencies of clarity. On the opposite side, you can have severe cancelations that rob you of "punch" or "chest-slam".
To counter those effects a smart placement and setup of speakers and subwoofers are key.
Contact our support team for assistance.