In order to understand how complex this sound field is, one must look at the sound pressure distribution within a room. These are the pressure areas that one must address in a listening room to control coloration . Coloration determines the quality of our sound we are trying to achieve. Controlling the pressure in these areas will reduce or eliminate coloration of our signal. The axial modes are made up of two waves going in opposite directions,traveling parrallel to one axis,and striking parallel to one axis, and striking only two walls.
Axial modes make the most prominent contribution to the acoustical characteristics of a space.
Because there are three axes to a rectangular room, there are three fundamental axial frequencies, each with its own train of modes. The tangential modes are formed by four traveling waves that reflect from four walls and move parallel to two walls. Tangential modes have only half the energy of axial modes, yet their effect on room acoustics can be significant. Each tangential mode has its train of modes. The oblique modes involve eight traveling waves reflecting from all six walls of an enclosure.