Modeling 120Hz bass response in my living room.
The subwoofer is in the upper right corner.
Red= high sound pressure in phase.
Blue= high sound pressure out of phase.
Yellow= low sound pressure.
The mathematical model is a simple one, derived by looking for low amplitude waves in the compressible Navier-Stokes equations.
Plot shows values predicted by a numerical simulation of my mathematical model. These gradients were later confirmed by testing with a decibelmeter.