We came across a Thiele-Small app the other night called Speaker Box Light and we were fairly pleased with the results.
From the description:
This service is designed for beginners and advanced fans of acoustic system building. The main feature is a calculation of the volume of the subwoofer box, according to his parameters Thiele-Small(FS, VAS, QTS). Calculation available vented and closed enclosures for each of them you can draw graphs of frequency response, phase response and time delays.
Also, the program provides recommendations for choosing of box type, an optimum volume of the box and the tuning frequency of vented box for your speaker. For vented case it is possible to calculate the parameters of the port: radius(if the cross section of the port circumference), width and height(if the cross-section rectangle) and its length.
We didn’t find any Pierce Audio Inc. speakers in the database yet but we may add some soon. Let us know if you are interested or want to collaborate on it. Contact Us here or Facebook to discuss more.