K_rose -
343/5.25/2=32.66Hz where 343m/s is the speed of sound, 5.25m is the distance between your walls, 2 is because you need two times distance to amplify (from speaker to back wall + back to front wall + front wall to speaker = 2x distance between walls). Exact multiples of 32.66Hz will be multiplied as well since their wavelength is an even fraction.
Nulling is pretty much the same with odd divisions.
343/5.25/2=32.66Hz where 343m/s is the speed of sound, 5.25m is the distance between your walls, 2 is because you need two times distance to amplify (from speaker to back wall + back to front wall + front wall to speaker = 2x distance between walls). Exact multiples of 32.66Hz will be multiplied as well since their wavelength is an even fraction.
Nulling is pretty much the same with odd divisions.