Originally Posted by pb21cyclist
OK so in theory a better result would be if the time spread was lower?
Why is there a 2kHz mountain?! Is that like a kind of resonance or something? And a 500-1k ridge?
500-1k ridge is natural, all headphones have that, to a varying degree. Although admittedly the HE400 500-1k are a bit problematic, as there is indeed some ringing in the 1k region of HE400s that can be heard just from some sinewave sweeps.
The 2kHz sharp ridge is a benign measurement artifact that is present in a lot of large diaphragm planar magnetic headphones and is seemingly undetectable by our hearing.
Originally Posted by Kjeldsen
Jerg, thanks for the chart. Mind a quick introduction to how to read it? Also, is there one for the earlier revisions around for comparison?
I'm pretty bummed about all the negative attention the HE-400's getting. I was pretty sure it was going to be my next headphone, but now i'm not so sure. Then again, i have no idea if i'll hear what everyone else is hearing.
CSD is basically a more sophisticated frequency response curve, that also has a time axis. You can see how fast the transient response is via seeing how quick the signal decays; usually at and under 0.5 ms is great. You can also see ringing via distinctive sharp ridges that drag across the time axis, some are benign, others actually mess up the sound. Also you can distinguish if sharp drops in frequency response are benign or actual valleys.
This measurement was a rev2 HE400 with velour pads.
Edited by jerg - 10/4/12 at 12:26pm