I have been playing with the HEX and HD800 and trying to get that perfect sound. They are quite relaxed and with a subtle tweak I really like what I have achieved so far. If someone else can give this a shot and tell me if they agree... download the Nova plugin for Jriver, and tweak the settings to be exactly what i've configured. It's not dramatic, but a tweak that really makes the HEX sing imho.
choose wideband Dyn for Program (top drop down window in Nova)
from left to right:
LP filter, 20.0khz 72db/oct
choose correct filter shape for all for 4 (turn on all 4 bands)
Band I - filter shape (left) / Q (steepness) dialed in at .89 / Freq @ 11Hz / Gain 12.0dB
Band II - filter shape (middle) / Q (steepness) 3.06 / Freq @ 1740Hz / Gain 2.6dB
Band III - filter shape (middle) / Q (steepness) 3.26 / Freq @ 5.5kHz / Gain 4.1dB
Band IIII - filter shape (middle) / Q (steepness) 2.53 / Freq @ 15.4kHz / 11.7dB
Gain 0db / threshold -5.0dB /ratio -5.0dB / wideband attack 5.5ms / release 10ms
dry mix 0.0% - Output Gain 2.5dB
this was a measurement I found online of the HEX freq response (green line), I went off this slightly to make adjustments accordingly to get to a closer freq response and smooth out the dips.
This only makes a small difference but adds just a hint of extra detail that imho seems to be missing, and likely would be fixed with a high grade cable like Norne Audio's Silvergard S or Zoetic. I'm going to have to try some new things to find that perfect sound. But I like the HEX better than my HD800's with sonarworks plugin. The open airy sound is so addicting, and with this little tweak it helps push it further up a notch.
I would say it's about 1-2% change that takes the high end and fills in some of the dippage without adding shrill or peaky treble like many headphones have. They still remain zero fatigue listening cans. I'm hoping to find the perfect cable to do away with the eq. But I find it quite fun since it's a pretty good eq! I hate eq's 99% of the time. They have a GE edition (gentlemens edition) with 6 bands. would definitely get a more accurate adjustment. Yet the HEX has a fairly nice freq response to begin with.