The air resonances greatly affect the acustic of a room designed for listen to musical tracks, the most important are the fundamental ones which have the half-wave lenght correspondent to the distance between walls and the ceiling.
ore then the fundamentals also the second and third harmonics manifest themselves. In some cases the second harmonic resonances tend to delete the fundamentals, on the other hand the third harmonic ones sum themselves to the fundamentals giving them more strong.
Pratically, a room suitable for listening to quality audio should have a goog golden ratio (which means more gap between fundamental resonances).
Useful width of the room ... W
Useful depth of the room ... D
Useful height of the room ... H
|Considered speed of sound||m/s|
|Resonance frequency between walls||W - W||Hz|
|Resonance frequency between walls||D - D||Hz|
|Resonance frequency between floor and ceiling||H - H||Hz|
The chart labeled as "Resultant" is an indication of the entity of the problem. It should be lower than possibile.
The golden ration of a room is the ratio between distance of the walls and the ceiling. In ideal cases the dimensions should give all resonances and various harmonics well separated between each other (on frequencies more different as possible).
The standing waves might be attenated using absorbent material or specific panels places on the walls. Using too much absorbent material will reduce too much the reverb time with negative effects.