The HiFiMAN Edition X is Delightful from Portable Players Measurements

Click on graphs image to download .pdf for closer inspection.

Raw frequency response plots show the Edition X is quite insensitive to positional change on the head. Response is essentially flat from 40Hz to 1.5kHz. Response falls off 5dB below 40Hz to 20Hz showing a modest lack of sub-bass extension. Response from 300Hz to 1.5kHz shouold show a gentle rise; I did hear this headphone as needing a slight lift in this area to bring vocals more forward.

Raw profile from 2kHz to 4kHz is just about right, but the fall-off after 4kHz is just a bit too fast. This is one of those instances where if I looked at the curve I'd say it's pretty darn close, but when I listen i hear the 4kHz and above information as more rolled-off than it looks on paper.

30Hz square wave does show significant sway back and crosses the zero line before transitioning to the next edge. Some of this is certainly due to the sub-40Hz bass roll-off, and the 100dBspl THD curve shows some rising character. I this case I think the bass sounds modestly better than it measures.

300Hz square wave is nicely horizontal, and the leading edge transient has appropriate height. Impulse response is similarly quick and, other than the second rebound, is quite noise-free for a planar magnetic headphone.

I have to say that although the treble may be a bit low in level, it seems very well behaved. This may be why while the Edition X may seem a little too rolled-off, it also images very well. It's also a perfect example of a headphone that measures well, but I wouldn't have guessed how it actually sounds from the measurements alone.

THD+noise plots show some sort of disturbance roughly from 800Hz to 2kHz, but it remains below 1% so it's likely not disturbing. I certainly didn't hear any hardness in listening.

Impedance and phase plot show a well behaved 23 Ohm planar magnetic headphone.

With 71mVrms needed to achieve 90dBspl at the ear, this is a headphone that will play plenty loud from portable devices.