Prices of each of the computer-based systems are varied. Some are pretty expensive but one of the popular freeware programs is Audia's Speaker Workshop. This system is popular because it measures system response. Another program that is popular for finding driver parameters is Claus Futtrup's Driver Parameter Calculator. This program is made specifically for obtaining the parameters you need. If you already own a computer and sound card, then use of these PC-based systems might be the most attractive option for you.

In any case, after you've obtained Frd, Vas and Qts, you'll enter these values into PiAlign. Actually, you'll want to enter the reciprocal (1/Qts) of Qts as Qd, Vas as Vad and Fts as Frd. The program will then recommend cabinet and port dimensions for you. For more information, please read the "readme.txt" file in the PiAlign distribution archive.