A free automated spreadsheet to calculate room acoustic measurements for home theaters. The only cells in which you need to enter data are in blue (length, width, height). Includes a row at the bottom of the spreadsheet that flags problem frequencies. It puts a "1" below each spot at which two resonant frequencies are within 5% of each other. The 5% threshold is the point at which different frequencies can be discerned by the human ear. If two resonant frequencies are within 5% of each other, the human ear cannot discern them, and they interfere with one another. Also includes a table listing the frequencies of single, double, and triple peaks and nulls based on the room dimensions and seating position.