In a recent thread, there has been some discussion about room modes. The company RealTraps makes a room mode calculator for Windows available. It is called ModeCalc, and information about this program and a download link can be found here. ModeCalc may be of assistance to those wishing to investigate improving their subwoofer's low-frequency sound reproduction in their listening environment. It computes only the axial modes up to a frequency limit of 500 Hz. The help file for ModeCalc suggests that axial modes are the most important ones to consider, because they are the strongest. An Excel spreadsheet for computing axial, tangential and oblique room modes is available from One On One Technical Products. Their Room Mode Calculator spreadsheet can be found here. It can provide a plot of the distribution of the axial modes, making it possible to visualise the locations of the dips in the sound pressure response at some of the room's modal frequencies. This can assist in placement of the listening position to try and avoid the big dips in response, making it more likely that electronic equalisation will be more effective without unduly stressing the subwoofer. There is also an online Room Eigenmodes Calculator. This particular program is interesting because, as well as computing the axial, tangential and oblique modes, it provides an isometric geometric representation of the (rectangular) room showing the sound pressure at the boundary surfaces of the room.