I couldn't resist doing one more power stepped harmonic distortion measurement while I was measuring the frequency behaviour of the second Carver and second B&G driver. Just wanted to check out of the measurements of yesterday were any valid. Measurements were performed under the same circumstances. Distance of the microphone to the ribbon was 1.5 inches.
Again two graphs, the first one from the B&G RD75-46 driver. Noticeable here is that for the last pass the distortion floor doesn't change much with exception of the 6 kHz peak. During the last pass there was apparently not enough power to excite a major harmonic distortion peak.
Following measurement was performed on my second Carver 60" driver. (This is the one with the smaller peak at 1 kHz.) The peak at 200 Hz in the fourth pass is my grandfather's clock in the room acting up ;-) This time there is a peak at 7 kHz, again not during the last pass at the lower power setting. There is overall only one major distortion peak in the 800-1 kHz area, although this one is lower compared with the other Carver driver with the "stronger" resonance.
