I measured the Sony XBA-H1s using a G.R.A.S. RA0045 ear simulator, a Clio FW audio analyzer, a laptop computer running TrueRTA software with an M-Audio MobilePre USB audio interface, and a Musical Fidelity V-CAN headphone amplifier. Measurements were calibrated for drum reference point (DRP): the equivalent of a headphone’s response at the surface of your eardrum. This is a “flat” measurement; no diffuse-field or free-field compensation curve was employed. Except as noted, I used the XBA-H1s’ medium standard tips. I experimented with the fit of the tips/earpieces by inserting and reinserting them in the RA0045, settling on the positions that gave the best bass response and the most characteristic result overall.

Frequency response

For an earphone, the XBA-H1s’ frequency response looks pretty flat overall, with perhaps a slight excess of energy between 3 and 5kHz. (Almost all headphones have a peak or two somewhere in this region.)

Frequency response

Adding 70 ohms output impedance to the V-CAN’s 5-ohm output impedance, to simulate the effects of using a typical low-quality headphone amp, tilts up the XBA-H1s’ response, dropping their bass output -1dB at 80Hz and kicking up the treble +5dB at 10kHz. Given my perception that the XBA-H1s sounded ever-so-slightly bright, even with the low-impedance output of my iPod Touch, I’d recommend using these headphones only with Apple or higher-end Android products, or with a separate headphone amplifier that has a low output impedance, preferably under 20 ohms.

Frequency response

Above 500Hz the XBA-H1s are fairly similar to the Audiofly AF78 hybrid and the RBH EP1 dynamic earphones, but the Sonys’ bass response looks much more neutral.


The spectral-decay (waterfall) plot looks very clean, with no notable resonances.


Total harmonic distortion (THD) at 100dBA is quite moderate overall, but with a little 10% peak centered near 3kHz; this drops to 3% at 90dBA. Considering that the first and second distortion harmonics of 3kHz are at 6 and 9kHz, respectively, your sensitivity to this distortion will vary inversely with your age, and more so if you’re male. (Translation: Your ability to hear higher frequencies decreases with age, especially in males.)


The spectrum of a 500Hz sinewave shows that the second and third distortion harmonics are nearly equal in level. It’d be nicer to see more second and less third, because odd-order harmonics are more objectionable, but the distortion is moderate anyway, so no big deal.


There’s not much isolation in the bass -- only about -8dB at 100Hz -- but it improves dramatically as the frequency rises: to -20dB at 1kHz, and about -30dB from 2.5 to 8kHz. That’s with the standard tips. The noise-isolating tip didn’t make a big difference, at least not when used in the cold-steel cone of the RA0045 ear simulator. It gave me an improvement of -8 to -15dB, but only at high frequencies: from 3 to 14kHz. I wonder how the results vary when the tips are inserted into a soft, warm ear canal.


The XBA-H1s’ impedance rises dramatically with frequency, running about 32 ohms below 1kHz, then rising to 186 ohms at 20kHz. The impedance phase rises similarly; it’s right near 0° at low frequencies, but jumps to +65° at 20kHz. Impedance swings at high frequencies are common in balanced-armature drivers, but I’d never before seen one so extreme. This causes the shift in tonal balance when the XBA-H1s are used with source devices that have a high output impedance.

The Sony XBA-H1s’ average sensitivity from 300Hz to 3kHz at the rated 40 ohms was very high, at 109.3dB.

. . . Brent Butterworth