when you calibrate analogue speakers and subwoofers you check their "bass handling capacity" and from that get a "Size" parameter. You stop when you start to hear distorsion.

Is this test just selecting one frequency and gradually raising the volume, or is it gradually lowering the frequency? If the latter is their a "standard" correspondence between Size and lowest frequency? If the former, what type of limiting is done?

HD621, G98DH, G68ADV, Bc Acoustiqe ACT A3, 5200C DSP33, NuForce Reference 9 monoblocks, 2x SB3's, Velodyne DD-15 & DD-12 Subwoofers and a Meridian sub.