Reviewed on: SoundStage! Solo, May 2020
I measured the TMA-2 HD Wireless headphones 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 TMA-2 HD Wirelesses’ frequency response with a wired connection. This curve is unusual in that the usual peak centered somewhere between 2kHz and 3kHz has moved up to span the octave from 4kHz to 8kHz, and also the entire treble range is a little low relative to the midrange and bass. There’s also a little extra energy in the upper bass and lower mids, although that’s fairly common.
This measurement shows the difference in frequency response between a wired connection and using the Bluetooth headband. (I used my Samsung Galaxy S10 phone with white noise as a source.) The minor differences you see are the result of the inaccuracy of the noise-based measurement; there’s effectively no difference in response between the two modes.
This chart shows how the TMA-2 HD Wirelesses’ 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 exotic tube amps. There’s no significant difference in response.
This chart shows the TMA-2 HD Wireless headphones’ right-channel response in wired mode compared with several closed-back headphones, including the AKG K371s, which are the headphones said to come closest to the Harman curve. The TMA-2 HD Wirelesses look a lot like the Drop + THX Panda headphones; they have the same unusual lack of energy at 2kHz, although they have a little less overall treble output. The peak around 150Hz makes them a little heavy in the upper bass.
The TMA-2 HD Wireless headphones’ spectral decay plot shows just one minor resonance at about 1.5kHz, but it’s well-damped.
Distortion is fairly low in the TMA-2s, at least in wired mode. At the very loud level of 90dBA, there’s a bit of distortion in the bass, but nothing noteworthy above 100Hz. At the crazy-loud level of 100dBA, distortion rises to between 1% and 2% above 100Hz, and gets higher in the bass, but I think unless you are listening to hip-hop or EDM cranked insanely loud, you’re not going to notice distortion with these headphones.
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. The isolation of the TMA-2 HD Wirelesses is comparable to that of competing open-back models. I added the NAD Viso HP70s so you could see how a typical noise-canceling model performs on this test.
The TMA-2 HD Wirelesses’ impedance magnitude is fairly flat, running between 36 and 42 ohms with a resonant peak at 75Hz, and the phase is just about dead-flat.
Sensitivity of the TMA-2 HD Wireless headphones in wired mode, measured between 300Hz and 3kHz, using a 1mW signal calculated for 32 ohms rated impedance, is 102.8dB, which means they’ll play pretty loud straight off a typical smartphone.
. . . Brent Butterworth
brentb@soundstagenetwork.com
