Reviewed on: SoundStage! Solo, October 2022
I measured the Meze Audio 109 Pro 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.
This chart shows the 109 Pros’ frequency response. There’s nothing particularly noteworthy here, it looks pretty typical for an open-back model—more or less flat below 1kHz, with a typical peak in the 3kHz range.
Here we can see the difference in the headphones’ response when a high-impedance (75 ohms) source is substituted for a typical low-impedance source (5 ohms). With the high-impedance source, the bass is boosted by about 1dB between 40 and 150Hz, which will be an audible but subtle difference.
This chart shows the 109 Pros’ right-channel response compared with a few other open-back models (including the Dan Clark Audio Æon 2s with perfed pads, which are the open-back headphones I’ve found come closest to the Harman curve). The 109 Pros seem well within the ballpark of normal.
Just for fun, I did a comparison of all the high-end Meze models in one chart. Interestingly, the 109 Pros seem to have bass that’s similar to the Empyreans, with treble that’s similar to the Elites.
The 190 Pros’ spectral decay is surprisingly clean for an open-back model; there’s a little bit of the super-high-Q midrange hash I’m used to seeing with these types of headphones, but much less than usual, which suggests that either the driver is well-damped or there’s some sort of acoustical damping going on, perhaps surrounding the driver on the ear side of the baffle.
Here’s the THD vs. frequency chart, measured at 90dBA and 100dBA, both levels set with pink noise. (Apologies for using 50% as the max value on the distortion scale; I usually use 20%.) Distortion in the bass is a little high, at roughly 5% at 20Hz; strangely, the distortion increased only marginally with the higher-level signal. Anyway, bass distortion is much less audible than midrange distortion, because the distortion harmonics fall mostly outside the ear’s most sensitive range, so I don’t expect this to be much of a problem.
In this chart, the external noise level is 85dB SPL (the red trace), and numbers below that indicate the degree of attenuation of outside sounds. The lower the lines, the better the isolation. The 109 Pros’ isolation is surprisingly low for a design based on a 50mm driver; this means these headphones may have a somewhat more open sound than most dynamic-driver open-back models, although they won’t block a significant amount of external sound.
The impedance of the 109 Pros mostly averages around 43 ohms, with a mild bump and corresponding phase shift in the bass that’s pretty common for dynamic drivers. This suggests there’ll be a very slight, and possibly inaudible, difference in bass response when you go from a low-impedance source to a high-impedance one.
Sensitivity of the 109 Pros, calculated for 40 ohms impedance and averaged from 300Hz to 3kHz, is 110.4dB; I can’t imagine there’s a source device that couldn’t get these cranking loud.
Bottom line: The Pros include safe’n’sane frequency response, very low resonance, and awesomely high sensitivity. The only con I can see is that the distortion’s a little high, but as I stated, given the frequency band where the distortion occurs, I doubt you’ll notice it. I didn’t.
. . . Brent Butterworth
brentb@soundstagenetwork.com