Reviewed on: SoundStage! Solo, June 2022
I measured the T3 Plus earphones using laboratory-grade equipment: a GRAS Model 43AG ear/cheek simulator/RA0402 ear simulator with KB5000/KB5001 simulated pinnae, and an Audiomatica Clio 12 audio analyzer. For isolation measurements, I used a laptop computer running TrueRTA software with an M-Audio MobilePre USB audio interface. The earphones were amplified using a Musical Fidelity V-CAN amplifier. I used the supplied medium-sized silicone tips for all measurements because they best fit in the ear simulator. 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 T3 Pluses’ frequency response. This is pretty much a by-the-book tuning, except there’s a little more output between about 100 and 300Hz than the Harman curve mandates, and the response above about 6kHz is a hair on the soft side.
This chart shows how the T3 Pluses’ 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. There’s no audible difference.
This chart shows the T3 Pluses’ right-channel response compared with various earphones, including the AKG N5005s, which are said to be the passive earphones that come closest to the Harman curve. Except as previously noted, these earphones are well within industry norms.
The T3 Pluses’ spectral-decay plot looks pretty clean, although it seems like there’s a bit of resonance below 300Hz. Possibly it’s the cause of my impression that the T3 Pluses sometimes sounded slightly on the bassy side.
There’s effectively no measurable distortion at the testing levels I used. This is an excellent result for a set of earphones.
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. In the 43AG ear/cheek simulator, the T3 Pluses, to my surprise, achieved better isolation with the silicone eartips than with the foam eartips. With the silicone eartips, isolation is perhaps a little better than average for the category.
The impedance curve of the T3 Pluses is mostly flat, running at 31 ohms through most of the audio range, and the phase response is very flat.
Sensitivity, measured between 300Hz and 3kHz, using a 1mW signal calculated for 32 ohms rated impedance, is 111.6dB, which means the T3 Pluses will play loudly from any source device.
Bottom line: These are very well-engineered earphones.
. . . Brent Butterworth
brentb@soundstagenetwork.com