Reviewed on: SoundStage! Solo, December 2022
I measured the Linsoul 7Hz Timeless 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. Except as noted, I used the supplied medium-sized silicone tips for all measurements because they fit best 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 7Hz Timelesses’ frequency response. This is fairly normal for earphones, with a few exceptions. There seems to be a bit of excess upper bass, and the 3kHz peak, while common, is unusually narrow in bandwidth. Also, there’s less energy in the mid-treble (around 7kHz) than we might normally see, but more energy above 10kHz than is normal for earphones. I can’t really speculate as to what this combination will sound like—maybe a little “smiley” (i.e., bass- and treble-boosted)?
This chart shows how the 7Hz Timelesses’ 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 a very tiny, and inaudible, bass boost below 30Hz.
This chart shows the 7Hz Timelesses’ 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. Basically, the variations from what’s more or less “normal” for earphones are as I described above.
The 7Hz Timelesses’ spectral-decay plot looks clean; that peak at around 3kHz corresponds with the earphones’ response peak at that frequency, and it’s very well-damped and won’t be audible as a resonance.
The distortion we see with the 7Hz Timeless earphones is much less than we normally see from earphones with dynamic drivers or balanced armatures—but comparable to what we usually see from planar-magnetic 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. In the 43AG ear/cheek simulator, the 7Hz Timelesses offer less isolation than most earphones do; I imagine that’s because their large size prevents them from filling the ear as completely as most earphones can.
The impedance curve of the 7Hz Timelesses is dead flat at 14 ohms, which is typical for planar-magnetic drivers. The phase response is also flat.
Sensitivity, measured between 300Hz and 3kHz, using a 1mW signal calculated for 14.8 ohms rated impedance, is 99.2dB. That’s low for earphones, but still high enough that the 7Hz Timelesses should play reasonably loud from almost any source device.
Bottom line: Looks like pretty solid engineering here, with high-quality drivers. There are some frequency-response anomalies; I’m eager to find out what Geoff Morrison heard.
. . . Brent Butterworth
brentb@soundstagenetwork.com