HiFiMAN Sundara Around-Ear Open Planar Magnetic Headphones Measurements

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

Raw frequency response plots show very little change in response with position change on the head. Reponse from 20Hz to 600Hz is quite flat. The Harman target response would indicate a gentle rise from 600Hz to about 1.5kHz is desired, but the Sundara remains prett flat in this area producing a somewhat laid back presence response. Vocals sound a bit distant to me.Though the rise to the peak at 3.3kHz is a bit abrupt, the peak is about 13dB above baseline...pretty much exactly where I like it. The falling response above 3.3kHz is nearly perfect as well, but for some glitching between 9kHz and 12kHz, which is almost certainly a result of normal (and usually inaudible) ear canal resonances.

But for a slightly too high initial transient, the 30Hz square wave has good shape for an open headphone with little sway-back and remaining above zero until the very end of the waveform. Though it's worth mentioning that Audeze headphones can sometimes do a bit better.

300Hz square wave initial transient and following rings are a bit ragged, and subsequent noise a bit high, but frankly, it sounded a somewhat better than this looks. I'm not saying the headphones sounded liquid smooth, they didn't, but I would have expected them to be a bit more grainy sounding than they were given the measurements. Impulse response is likewise somewhat noisy. It's guessing we'll see some some "Ortho Wall" action 2kHz, 6kHz, and 9kHz when the SBAF boys do their CSD plots, but I reckon it'll be fairly low level stuff.

Distortion is fairly low across the board, but a slight rise at 2kHz and 6kHz may evidence some mild break-up at those frequencies.

Impedance is dead flat at 43 Ohms, with only a gentle change in electrical phase in the top octave. The lack of visible features in the impedance plot usually points towards a well behaved headphone.

Isolation is minimal and typical for an open headphone. Needing 245mVrms to drive these headphones to 90dBspl at the ear indicates it will not be easily driven to loud levels from portable devices. I'd recomend and amp or dedicated DAP for portable use.