Reviewed on: SoundStage! Solo, October 2021

I measured the Sendy Audio Peacock headphones using laboratory-grade equipment: a GRAS Model 43AG ear/cheek simulator/RA0402 ear simulator with KB5000/KB5001 simulated pinnae, and an Audiomatica Clio 12 QC audio analyzer. For isolation measurements, I used a laptop computer running TrueRTA software with an M-Audio MobilePre USB audio interface. For most measurements, the headphones were amplified using a Musical Fidelity V-CAN amplifier; I used a Schiit Magnius amplifier for distortion measurements. These are “flat” measurements; no diffuse-field or free-field compensation curve was employed. If you’d like to learn more about what our measurements mean, click here.

Frequency response

This chart shows the Peacocks’ frequency response. This is not too crazy for headphones of this type, although with less bass output than I expected, but I guess the relatively mild 3kHz peak in the low treble balances that out. There’s more energy above 5kHz than I’m used to seeing; that combined with the low 3kHz peak might be how these headphones manage to deliver detail without seeming bright.

Frequency response

This chart shows how the Peacocks’ tonal balance changes when they’re used with a high-impedance source, such as a cheap laptop, some tube amps, or some professional headphone amps. As usual with planar-magnetic drivers, there’s no significant difference.

Frequency response

This chart shows the Peacocks’ right-channel response compared with three other open-back audiophile headphones: the HiFiMan HE6se, the Audeze LCD-X, and the Dan Clark Æon 2, fitted with their optional perfed pads, which come pretty close to the Harman curve. You can see how attenuated the Peacocks’ bass response is relative to the others, and also how mild its 3kHz peak is relative to most of the others.


As with most planar-magnetic headphones, the Peacocks’ right-channel spectral-decay plot shows super-high-Q hash in the upper mids, in this case between about 1 and 3.5kHz—which I suspect gives most planars a greater sense of “air” and spaciousness. There is a very strong resonance around 7.3kHz, which corresponds with a cancellation/reinforcement peak in the frequency-response measurement, but the frequency and Q are so high that I doubt it’ll be troublesome.


Here’s the THD vs. frequency chart, measured at 90dBA and 100dBA (both levels set with pink noise). Distortion is negligible—a couple percent in the bass, but it’d need to be more like 10% to be audible at those low frequencies.


In this chart, the external noise level is 85dB SPL, and numbers below that indicate the degree of attenuation of outside sounds. The lower the lines, the better the isolation. I compared them with some other high-end models, and the Peacocks’ isolation is typical for their product category. I threw in the Audeze LCD-2 Closed-Back headphones so you could see how this compares with a closed-back design.


As is the norm with planar-magnetic headphones, the impedance magnitude is essentially flat, averaging 48 ohms, and the phase response is similarly flat.

Sensitivity, measured between 300Hz and 3kHz, using a 1mW signal calculated for 32 ohms rated impedance, is 101.1dB. That should be enough to get the Peacocks playing pretty loud with almost any source device.

Bottom line: The Sendy Audio Peacock headphones measure just fine. I see no technical concerns here.

. . . Brent Butterworth