Ok, tried again, but this time I used a
rubber band to make sure seal was achieved... and perhaps driver and mic got a little closer, but anyhow this are the results:
Frequency Response
Distortion Right
Distortion Left
CSD Right
CSD Left
As far as which measurements are more "right" (vs
this ones),
depends I guess on how good of a seal one actually gets. This is not necessarily easy with this cans. That said, I believe these represent as good as one is going to get under ideal conditions (specially the left driver measurement). The deep & narrow null at around 4.5 kHz might be a measurement artifact though.
Also, as far as the issue with 100 dB, I believe it's due to
the amp being pushed too hard. Previously I feed a signal at -20 dBFS and achieved 100 dBSPL by pushing the SRM-323S volume knob almost to the max (
issue was repeated today). However, if I feed a -10 dBFS signal instead, I get much better results (high order harmonics in the treble region):
Comparo again with SR009 and HD600s:
As said before, I feel the SR307 have this upper mids and treble shoutiness to them relative to the HD600s. Best guess is that this is due to the depression in the upper mids relative to the treble.