The HiFiMAN HE6 Remastered is 50Ω. Its maker prints a sensitivity of 83.5 dB and never says whether that is per milliwatt or per volt, so this page reads it as per milliwatt — on that reading it needs 45 mW to reach 100 dB SPL, or 1.49 V across the drivers. If the figure is really per volt, it needs far more.
That is a demanding load — not impossible from a portable source, but you want a good one. 97 of the 280 sources have at least 10 dB of headroom, 95 more have enough, 48 are marginal and 40 fall short. The cheapest portable source that does the job is the FiiO KA11 at $29.
This maker printed a decibel figure and no reference unit, so the number above is shown exactly as printed. Everything below reads it as per milliwatt, which is the commoner convention on a sheet that omits the unit — if it is really per volt, this headphone is about 13 dB harder to drive than the rest of this page assumes. The converter explains the difference.
HiFiMAN publishes a sensitivity of 83.5 dB and does not state whether that is per milliwatt or per volt — the spec sheet simply stops at the number.
Both readings are given here so you can judge for yourself. If that 83.5 dB is per milliwatt, the figures on this page are right as they stand. If it is per volt, the real sensitivity is 70.5 dB/mW — 13 dB lower at 50Ω — and everything above understates what these need by that much. The per-milliwatt reading is the one shown, because it is the more common convention on a spec sheet that omits the unit; treat it as an indication rather than a specification.
Source: hifiman.com, store.hifiman.com. How this data was built.
| As it is labelled | As printed | Tolerance | Standard |
|---|---|---|---|
| Frequency Response | 8 Hz - 65 kHz | not printed | not printed |
HiFiMAN prints 8 Hz - 65 kHz for the HiFiMAN HE6 Remastered, under the heading “Frequency Response”. Source: hifiman.com.
No tolerance is printed with it, so “8 Hz - 65 kHz” says nothing about how loud this headphone actually is at 8 Hz.
Only what the maker printed; maker by maker.
| Level | What it is | Power | Voltage | Current |
|---|---|---|---|---|
| 85 dB SPL | quiet background listening | 1.4 mW | 0.27 V | 5.3 mA |
| 95 dB SPL | normal listening | 14 mW | 0.84 V | 16.8 mA |
| 100 dB SPL | loud listening | 45 mW | 1.49 V | 29.9 mA |
| 105 dB SPL | very loud | 141 mW | 2.66 V | 53.2 mA |
| 110 dB SPL | peaks on dynamic music | 447 mW | 4.73 V | 94.5 mA |
Most people listen between 75 and 85 dB; the 100 dB row leaves room for peaks.
The 15 cheapest of the 280 sources here that reach 100 dB SPL into 50Ω with at least 10 dB of headroom and no known hiss or output-impedance problem with these headphones. All 280 sources, judged for these headphones.
| Source | Type | Price | Power into 50Ω | Headroom | Verdict |
|---|---|---|---|---|---|
| JDS Labs Atom+ (2nd gen) | desktop amplifier | $99 | 762 mW | +12 dB | Comfortable |
| Schiit Magni Heresy | desktop amplifier | $99 | 1.6 W | +16 dB | Comfortable |
| Schiit Magni+ | desktop amplifier | $109 | 1.3 W | +15 dB | Comfortable |
| Schiit Magni Unity | desktop amplifier | $119 | 1.5 W | +15 dB | Comfortable |
| JDS Labs Atom Amp 2 | desktop amplifier | $129 | 1.7 W | +16 dB | Comfortable |
| Schiit Vali 3 | desktop amplifier | $149 | 1.0 W | +14 dB | Comfortable |
| Topping L30 II | desktop amplifier | $149 | 2.2 W | +17 dB | Comfortable |
| SMSL HO100 | desktop amplifier | $160 | 975 mW | +13 dB | Comfortable |
| xDuoo MT-604 | desktop amplifier | $169 | 1.3 W | +15 dB | Comfortable |
| TempoTec Variations V3 Blaze | portable player | $179 | 528 mW | +11 dB | Comfortable |
| FiiO K7 | desktop DAC/amp | $199 | 785 mW | +12 dB | Comfortable |
| iFi Zen CAN | desktop amplifier | $199 | 1.1 W | +14 dB | Comfortable |
| Geshelli Archel Pro | desktop amplifier | $200 | 1.2 W | +14 dB | Comfortable |
| Schiit Magni Piety | desktop amplifier | $200 | 800 mW | +13 dB | Comfortable |
| SMSL C200 | desktop DAC/amp | $219 | 832 mW | +13 dB | Comfortable |
Hiss. At 96.5 dB/V these are sensitive enough to reveal a source's own noise floor. The noisiest source in the database, the Schiit Mjolnir 3, would put its hiss at roughly 5 dB SPL in these headphones — faintly audible in a silent room. Check your own source.
Output impedance. At 50Ω these want a source output impedance below 6.25Ω to satisfy the one-eighth rule; 34 of the 192 sources that publish one miss it. Check yours here.
Volume is not the test. Plenty of weak sources will play these loud enough. What runs out first is control on bass peaks, where the current demand spikes well above the average figures in the table. If it sounds loud but soft, that is what you are hearing.
50Ω · 83.5 dB · Demanding
See requirements →45Ω · 86.0 dB · Moderate
See requirements →60Ω · 83.0 dB · Demanding
See requirements →300Ω · 91.8 dB/mW · Demanding
See requirements →60Ω · 83.8 dB/mW · Demanding
See requirements →15Ω · 81.8 dB/mW · Moderate
See requirements →Compared with its stablemates: vs Ananda Nano · vs Edition XV · vs HE-R9 · vs Susvara Unveiled.