Okie dokie, here's my measurements.
The first one is the Leather pads, velour on the second.
Click the image to get the .pdf
I'll have a LOT to say about these measurements when I do the review, but for the moment I'll draw your attention to the 2 little blips on the impedance curve at 250Hz and 400Hz. You'll also note a rise in THD+noise at those frequencies. These are blips due to a dual primary driver resonance---one is the diaphragm as a whole, and the other is the driver resonance of a more central portion of the driver that has a different resonance due to the traces on the diaphragm surface. I got all this info from Igor via email. My brief interpretation here may or may not be totally accurate, but it should be close.
You'll also notice that the THD+noise as a whole----other than the blips---is VERY low, and the blips don't hit the 1% level untill you get to 100dBspl. It's very important to note here that THD+noise is a pretty uninformative measure, and there are types of distortion that are more disturbing than others, and all will be reported similarly on THD+noise measurements. For example, if the distortion is even-order, it will be much less disturbing than if it is odd-order. The point is, when looking at these artifacts, it's important to note that the peaks in distortion are really quite small, they just look big relative to the very low distortion otherwise.
I have spent very little time listening to these cans, but my initial impression is that they have a smooth, creamy sound that's very pleasant, though maybe a little muffled sounding...just a little, but this headphone plays in the reference headphone area and nits are worthy of picking. I have lots more listening to do however. I will be listening to see if I can hear the distortion or not. I will take some measurements of harmonic structure using a probe tone at the two peaks and nearby the peaks to see if the harmonics change ratios significantly---IOW, at the distortion frequency there may be more second or third harmonic at the peaks than in undisturbed areas.
Igor said he agreed that the measurements are representative of the product. Personally, I'd rather not see the distortion blips there, but Igor's explanation was quite thorough and sensible, and it seemed to me we may have one of those cases where the measurements are telling us something that's a bit complicated, and you can't just say "more distortion is bad" with any kind of certainty.
I will happily say right now though, that the build quality, comfort, looks, and accessories of these headphones is top-notch.
This is going to be an interesting headphone.