In Reply to: A couple questions about Pi-alignment posted by Tightwad on September 23, 2003 at 19:40:08:
The formulas used to calculate the cabinet from the speaker's electro-mechanical properties are the same whether you use T/S specs or the PiAlign equivalents. Specifically, the T/S compliance figure is Vas and equal to PiAlign's Vad, Fts is the same as Frd and Qts = 1/Qd.You can also use the sealed box method or the added mass method to find these values. Measurements of the electro-mechanical properties of a speaker are much more likely to be reasonably accurate than measurements that involve the acoustic domain, because finding electro-mechanical parameters doesn't require any acoustic measurements. So these kinds of measurements can be obtained with probably something like 20% tolerance using equipment that is commonly available to DIY builders.
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