Well if you already know what you are looking for in terms of volume (cu. ft) and some general dimensions for a subwoofer, check out Boxnotes. It's a software program designed mainly for subwoofers ...

October 18, 2013. Audio Precision has announced a new software release that expands the features of the electro-acoustic test suite for APx audio analyzers. APx v3.4 adds Thiele/Small parameters, ...