Room Modes App

The Room Modes Application calculates the modal response of a room at the lowest frequencies where the modal situation is dominate. This program is unique from all others (that I know of) in that it uses complex modes. (In reality all rooms with sound absorption have complex modes.) Complex modes are fundamentally different than real modes in several ways. First, only if the modes and the entire set of calculations are complex can there be any real energy flow in the room as would be required if there was localized sound absorption. In most modal programs the "damping" is added to the summation as a singular damping term - a global complex terms that attempts to account for the sound absorption. With this form of damping the sound is absorbed equally and continuosly throughout the space as would happen if the absorption were entirely air absorption. This is, of course, not the case since at low frequencies virtually all sound absorption takes place at the walls. If the damping is small then these differences in the two approaches are minimal. But for larger wall absorption - particularly when it is not uniformly applied - the differences can be quite substantial.
The price for these more accurate calculations is speed - the complex calculations take a lot longer than the far simpler real calculations. However the results can be far more accurate when the wall absorption is not uniformly applied (as it is in my room, for example.)

In this application the room layout is shown for the X-Y (floorplan) plane and the Y-Z plane. The sources are draged about the room with the mouse as can the listener as well. Dragging the upper main moves both source symmetrically. Dragging the lower one moves just this main. Both mains must be at the same height.
Right clicking on a source will bring up it parameters which include the drivers parameters and those of its amplifier. Some EQ is available. Both mains operate from the same set of parameters, but each such is independent.

Run Polar Map

The application requires .Net 3.5 or later to run.