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Room Modes
If we do not have at least half wavelength distances within our rooms to accommodate especially low-frequency waves, we will have the waves telling us that they are not happy with the accommodations we have given them. They will do this by producing resonances that tell us they think their quarters are too cramped. They will produce resonances between each of our room boundary surfaces. If the resonances they produce occur between two parallel surfaces, they are termed axial resonances. Resonances produced between four surfaces are termed tangential resonances and resonances from six surfaces are termed oblique. The issues these resonances produce are called room modes and modes are produced by what is termed standing waves. Standing waves are produced because the length of sound waves does not fit within the room dimensions.