Reviewed on: SoundStage! Solo, August 2020
I measured the EarSonics Stark earphones using laboratory-grade equipment: a G.R.A.S. Model 43AG ear/cheek simulator/RA0402 ear simulator with KB5000/KB5001 simulated pinnae, and a Clio 10 FW audio analyzer. For isolation measurements, I used a laptop computer running TrueRTA software with an M-Audio MobilePre USB audio interface. The headphones were amplified using a Musical Fidelity V-CAN. 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.
The above chart shows the Starks’ frequency response. This measurement was done with the supplied small foam tips, which were the only ones that fit the ear simulator well. The boosted midrange band that I noted in my listening tests is readily apparent, and centered at about 1.5kHz. If you moved the peaks at 1.5 and 4kHz up by about 1kHz higher, this would be a fairly typical earphone measurement.
This chart shows how the Starks’ tonal balance changes when they’re used with a high-impedance (75 ohms) source, such as a cheap laptop or some cheap professional headphone amps, or some tube amps. For earphones with balanced armatures, this is a pretty small difference: an average of +2dB in the bass and +1dB in the treble when using the high-impedance source. So they’ll maintain most of their tonal character no matter what source device you use.
This chart shows the Stark earphones’ response compared with the EarSonics Purples (with the tone control set in the middle, right channel), the Campfire Solarises, and the AKG N5005s, which are said to be the passive earphones that (with their Reference filter installed) best conform to the Harman curve. It’s easy to see what I mean by moving the peaks at 1.5 and 4kHz up by 1kHz; in that case, the Starks would essentially be Harman curve earphones.
The Starks’ spectral decay plot looks very clean, suggesting there are no troublesome resonances.
The distortion of the Starks is low at the loud level of 90dBA (measured with pink noise), and only about 1 to 2% measured at the crazy-loud level of 100dBA.
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. With the double-flange silicone tips fitted, the Starks offer excellent isolation, comparable to that of most other models using over-ear cable routing. Results aren’t nearly as good with the foam tips, but that’s probably just because the double-flange tip happens to fit the KB5000 simulated ear best.
For earphones using balanced armatures, this impedance curve is surprisingly flat, running 13 to 16 ohms through most of the audioband. Phase response is similarly flat.
Sensitivity of the Stark earphones, measured between 300Hz and 3kHz, using a 1mW signal calculated for 18.5 ohms rated impedance, is 112.3dB -- well below the rated sensitivity of 125dB, but still easy for any source device to drive.
. . . Brent Butterworth
brentb@soundstagenetwork.com