I've been playing with waterfalls tonight, and am pretty comfortable with the way the tests and software are working.
The following is a waterfall of a good measurement of my LCD2:
This is the Rastapants 2 PLUS 6-7 regular cotton balls, 3.5 vent slots closed, and the center inside driver square with a reflex dot (just added, it took a bite out of but didn't totally eliminate the 3-5KHz dip):
From these charts, which reproduce consistently with variations expected based on exact microphone position, you can see the T50 Rastapants 2 has a cleaner and faster decay and except for the 3-5K region has more mid and treble output with a smoother response.
Before anyone makes too much of the comparative charts, it is extremely probable that some of the spectrum from 500-1000Hz on the LCD and at a lower level on the RP2 is ambient noise from disk drives and other junk in the house, so focus more on the highs. I am pretty certain that the LCD2 performs better than the waterfall indicates, given that it's a fully open design high frequency ambient noise is almost certainly polluting the response (not so the resonance at 9K, that was in Purrin's tests, too, and the resonance is clearly part of the system, not my lab noise). Until I build an anechoic test box a la Tyll, open air cans will likely test at a disadvantage.
Here is the frequency response (the sound is freaking ROCKING tonight):
I'm also very pleased by the THD:
It's pretty much less than 1% below 100Hz, and between .05 and .15% through the rest of the range. I suspect the spike at 600Hz correlates to the notch in the frequency response, where there is a bit of ringing. Same thing at about 42Hz. A good rule of thumb is a notch in the response will indicate some kind of resonance/standing wave, at 42Hz though, I am wondering if this is a panel resonance.
Since I see Tyll is watching the thread, I think I can pretty safely say these are pretty good results. Running results without moving the head has generated plats that have been within a 1-2 DB variance, and if I put the phones back in the same spot are highly repeatable.... Tyll, any comments on the performance you see here? I haven't calibrated the round trip DAC->ADC to calibrate the electronics, so they may be contributing a bit of distortion here that's not accounted for...