Mr Speakers Ether C is a World Class Sealed Headphone Measurements

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Raw frequency response plots show a bass response that's fairly flat for a sealed headphone. Some wiggles in the bass due to pad bounce are quite normal in a sealed can. While I did hear the bass as being a tad soft, bass is quite well behaved and well extended. The Harman target response would want the bass to be elevated 3-5 dB below 150Hz, and I did hear these cans as a little bass-light.

Raw response above 300Hz shows an ever-increasing response to the peak at 3.5kHz; this is near ideal according to the Harman target. I would like to see this peak just a few dB lower and more rounded at the peak. None the less, the mid-range balance sounds very, very good to my ears. Lack of bass and the slightly high peak make these cans tend slightly towards lean.

Treble response drop from 3.5kHz and up has a very good profile, again matching the Harman response curve well. This area is slightly marred by a high-Q feature at 10kHz, likely caused by a resonance between the flat magnet structure and the side of your head. This feature can be somewhat reduced by adding one black tuning filter, but the added muting of the treble seems a bit too much to my ears. A close call; but fun to play with.

30Hz square wave top is slightly misshapen by pad bounce, but the waveform remains high until the transition to the next edge evidencing good extension.

300Hz square wave shows the 3.5kHz concha resonance as a slightly under-damped series of three ever smaller wiggles. This feature can be seen on many good headphones (including the HD 600) and I consider it non-optimal but benign. Height of initial transient edge is a bit high, and the slightly downward sloping waveform top indicate a slightly lean sounding response, which I did hear in listening.

Impulse response also shows some concha ringing, but is otherwise quite noise-free.

THD+noise plots are a tad high, but fairly well behaved across the response range. It is possible that the noise background on the day of measurement was a bit high. The 100dBspl plot remains lower than the 90dBspl plot over most of its range indicating good power handling capability. I did play these cans quite loud at time and found them very good. There is a slight increase in bass distortion at very low frequencies at 100dB that may evidence the slight softness I hear in the lows.

Impedance plots show a 22 Ohm headphone with a flat response as would be expected of a planar magnetic headphone. Close-up inspection of the plot will reveal some very small variations, but nothing that would indicate any acoustic resonance problems near the driver.

Isolation is very good for a sealed headphone with -22dB of broadband attenuation. The rise above zero between 70Hz and 170Hz is confirming evidence of pad bounce, but is well within the norm for a full-sized sealed headphone. This is about as much isolation as one can reasonably expect from a headphone of this type. You'd have to go to an IEM or noise canceler to get more isolation.

With 117mVrms needed to achieve 90dBspl at the ear these will not play loud on portable devices; a portable amp is suggested.

This is an excellent set of measurements for a headphone of this type.

MrSpeakers Headphone Products
3366 Kurtz Street
San Diego, CA 92110