The HiFiMAN HE1000 V2 is 35Ω with a sensitivity of 90.0 dB/mW, which is 104.6 dB/V. To reach 100 dB SPL — genuinely loud, louder than most people listen — it needs 10 mW, or 0.59 V across the drivers.
That is a moderate load. Most USB dongles handle it without complaint; the weakest phone outputs will run out of volume before they run out of quality. 52 of 53 sources here have enough headroom. The cheapest portable source that does the job is the Apple USB-C dongle (US) at $9.
Sensitivity here is in dB per milliwatt. Manufacturers often quote dB per volt instead and leave the unit off, which is the single most common reason online calculators give answers that are 10–15 dB wrong. The converter explains the difference.
| Level | What it is | Power | Voltage | Current |
|---|---|---|---|---|
| 85 dB SPL | quiet background listening | 0.32 mW | 0.11 V | 3.0 mA |
| 95 dB SPL | normal listening | 3.2 mW | 0.33 V | 9.5 mA |
| 100 dB SPL | loud listening | 10 mW | 0.59 V | 16.9 mA |
| 105 dB SPL | very loud | 32 mW | 1.05 V | 30.1 mA |
| 110 dB SPL | peaks on dynamic music | 100 mW | 1.87 V | 53.5 mA |
Most people listen between 75 and 85 dB. The 100 dB row is the one worth planning around: it gives you headroom for dynamic peaks without designing your system for a volume that would damage your hearing in under fifteen minutes. The safe listening calculator puts numbers on that.
Every source in the database, judged at 100 dB SPL into 35Ω. “Headroom” is how much power is left over above what the headphone needs — 10 dB means ten times the required power, which is what you want for dynamic peaks.
| Source | Type | Price | Power into 35Ω | Headroom | Verdict |
|---|---|---|---|---|---|
| Schiit Ragnarok 2 | desktop amplifier | $1500 | 22.2 W | +33 dB | Comfortable |
| Chord Hugo TT 2 | desktop amplifier | $5000 | 7.5 W | +29 dB | Comfortable |
| Burson Soloist 3X GT | desktop amplifier | $1500 | 7.4 W | +29 dB | Comfortable |
| Schiit Mjolnir 3 | desktop amplifier | $800 | 7.4 W | +29 dB | Comfortable audible hiss |
| Ferrum OOR | desktop amplifier | $1800 | 6.6 W | +28 dB | Comfortable |
| Schiit Asgard 3 | desktop amplifier | $250 | 6.5 W | +28 dB | Comfortable |
| Wells Audio Milo | desktop amplifier | $2500 | 5.6 W | +28 dB | Comfortable |
| Topping A90 Discrete | desktop amplifier | $400 | 5.6 W | +27 dB | Comfortable |
| Topping A90 | desktop amplifier | $500 | 5.1 W | +27 dB | Comfortable |
| Headamp GS-X Mini | desktop amplifier | $1400 | 4.7 W | +27 dB | Comfortable |
| JDS Labs Element III MK2 | desktop DAC/amp | $350 | 4.2 W | +26 dB | Comfortable |
| SMSL HO200 | desktop amplifier | $300 | 3.7 W | +26 dB | Comfortable |
| iFi iCAN Pro | desktop amplifier | $600 | 3.7 W | +26 dB | Comfortable audible hiss |
| Topping L30 II | desktop amplifier | $130 | 3.2 W | +25 dB | Comfortable |
| Cayin HA-6A | desktop amplifier | $1800 | 2.8 W | +24 dB | Comfortable audible hiss |
| FiiO M17 | portable player | $1800 | 2.8 W | +24 dB | Comfortable |
| Fiio K9 Pro | desktop DAC/amp | $380 | 1.9 W | +23 dB | Comfortable |
| Schiit Magni+ | desktop amplifier | $109 | 1.8 W | +23 dB | Comfortable |
| Fiio K7 | desktop DAC/amp | $180 | 1.8 W | +23 dB | Comfortable |
| Geshelli Archel Pro | desktop amplifier | $200 | 1.7 W | +22 dB | Comfortable |
| Schiit Magni Heresy | desktop amplifier | $100 | 1.5 W | +22 dB | Comfortable |
| SMSL SH-9 | desktop amplifier | $150 | 1.4 W | +21 dB | Comfortable |
| JDS Labs Atom+ (2nd gen) | desktop amplifier | $100 | 939 mW | +20 dB | Comfortable |
| iFi Zen CAN | desktop amplifier | $200 | 939 mW | +20 dB | Comfortable |
| HiBy R6 Pro II | portable player | $750 | 697 mW | +18 dB | Comfortable |
| FiiO M11S | portable player | $500 | 621 mW | +18 dB | Comfortable |
| FiiO KA17 | USB dongle | $150 | 605 mW | +18 dB | Comfortable |
| FiiO BTR17 | Bluetooth receiver | $200 | 602 mW | +18 dB | Comfortable |
| Astell&Kern SP3000 | portable player | $3700 | 557 mW | +17 dB | Comfortable |
| FiiO KA13 | USB dongle | $80 | 509 mW | +17 dB | Comfortable |
| Qudelix T71 | Bluetooth receiver | $200 | 372 mW | +16 dB | Comfortable |
| Astell&Kern SR35 | portable player | $800 | 372 mW | +16 dB | Comfortable |
| FiiO BTR15 | Bluetooth receiver | $110 | 314 mW | +15 dB | Comfortable |
| FiiO BTR7 | Bluetooth receiver | $200 | 296 mW | +15 dB | Comfortable |
| Questyle M15 | USB dongle | $250 | 279 mW | +14 dB | Comfortable |
| Hidizs S9 Pro | USB dongle | $75 | 248 mW | +14 dB | Comfortable |
| Sony NW-WM1AM2 | portable player | $1400 | 232 mW | +14 dB | Comfortable |
| Qudelix 5K | Bluetooth receiver | $110 | 221 mW | +13 dB | Comfortable |
| Moondrop Dawn Pro | USB dongle | $60 | 212 mW | +13 dB | Comfortable |
| iBasso DC04 Pro | USB dongle | $90 | 212 mW | +13 dB | Comfortable |
| Shanling UP5 | Bluetooth receiver | $130 | 212 mW | +13 dB | Comfortable |
| Truthear SHIO | USB dongle | $70 | 197 mW | +13 dB | Comfortable |
| Schiit Vali 2+ | desktop amplifier | $200 | 188 mW | +13 dB | Comfortable audible hiss, damping |
| FiiO KA11 | USB dongle | $30 | 185 mW | +13 dB | Comfortable |
| ddHiFi TC44 Pro | USB dongle | $110 | 176 mW | +12 dB | Comfortable |
| Shanling UA5 | Bluetooth receiver | $220 | 166 mW | +12 dB | Comfortable |
| Tempotec Sonata BHD Pro | USB dongle | $40 | 120 mW | +11 dB | Comfortable |
| iBasso DC03 Pro | USB dongle | $60 | 111 mW | +10 dB | Comfortable |
| EarStudio ES100 MK2 | Bluetooth receiver | $90 | 56 mW | +7 dB | Enough |
| Generic CX31993 dongles | USB dongle | $12 | 55 mW | +7 dB | Enough faint hiss |
| Sony NW-A306 | portable player | $350 | 46 mW | +7 dB | Enough |
| Apple USB-C dongle (US) | USB dongle | $9 | 28 mW | +4 dB | Enough faint hiss |
| Apple USB-C dongle (EU) | USB dongle | $9 | 14 mW | +1 dB | Marginal faint hiss |
Hiss. At 104.6 dB/V these are sensitive enough to reveal a source's own noise floor. The noisiest source in the database, the Schiit Vali 2+, would put its hiss at roughly 13 dB SPL in these headphones — clearly audible in quiet passages. The hiss calculator lets you check your own amplifier's noise figure.
Output impedance. At 35Ω these want a source output impedance below 4.38Ω to satisfy the one-eighth rule. 1 of the 53 sources here miss it, the worst being the Schiit Vali 2+ at 6Ω. Above that threshold the source starts shaping the frequency response. Check yours here.
35Ω · 93.0 dB/mW · Easy
See requirements →35Ω · 93.0 dB/mW · Easy
See requirements →35Ω · 90.0 dB/mW · Moderate
See requirements →55Ω · 92.0 dB/mW · Moderate
See requirements →55Ω · 92.0 dB/mW · Moderate
See requirements →42Ω · 91.0 dB/mW · Moderate
See requirements →Or open the comparison tool to put any two models side by side, or browse all 316.