The AKG K712 Pro is 62Ω with a sensitivity of 94.0 dB/mW, which is 106.1 dB/V. To reach 100 dB SPL — genuinely loud, louder than most people listen — it needs 4.0 mW, or 0.50 V across the drivers.
That puts it in the easy category. A phone, a laptop headphone jack or the cheapest USB dongle will drive it to painful levels. Of the 53 sources in the database, 53 have comfortable 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 | 0.13 mW | 88 mV | 1.4 mA |
| 95 dB SPL | normal listening | 1.3 mW | 0.28 V | 4.5 mA |
| 100 dB SPL | loud listening | 4.0 mW | 0.50 V | 8.0 mA |
| 105 dB SPL | very loud | 13 mW | 0.88 V | 14.2 mA |
| 110 dB SPL | peaks on dynamic music | 40 mW | 1.57 V | 25.3 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 62Ω. “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 62Ω | Headroom | Verdict |
|---|---|---|---|---|---|
| Schiit Ragnarok 2 | desktop amplifier | $1500 | 14.0 W | +35 dB | Comfortable |
| Chord Hugo TT 2 | desktop amplifier | $5000 | 5.3 W | +31 dB | Comfortable |
| Burson Soloist 3X GT | desktop amplifier | $1500 | 4.8 W | +31 dB | Comfortable |
| Ferrum OOR | desktop amplifier | $1800 | 4.7 W | +31 dB | Comfortable |
| Schiit Mjolnir 3 | desktop amplifier | $800 | 4.6 W | +31 dB | Comfortable audible hiss |
| Wells Audio Milo | desktop amplifier | $2500 | 4.0 W | +30 dB | Comfortable |
| Schiit Asgard 3 | desktop amplifier | $250 | 3.9 W | +30 dB | Comfortable |
| Topping A90 Discrete | desktop amplifier | $400 | 3.5 W | +29 dB | Comfortable |
| Topping A90 | desktop amplifier | $500 | 3.4 W | +29 dB | Comfortable |
| Headamp GS-X Mini | desktop amplifier | $1400 | 3.1 W | +29 dB | Comfortable |
| JDS Labs Element III MK2 | desktop DAC/amp | $350 | 2.4 W | +28 dB | Comfortable |
| SMSL HO200 | desktop amplifier | $300 | 2.4 W | +28 dB | Comfortable |
| iFi iCAN Pro | desktop amplifier | $600 | 2.3 W | +28 dB | Comfortable audible hiss |
| Cayin HA-6A | desktop amplifier | $1800 | 2.0 W | +27 dB | Comfortable audible hiss |
| FiiO M17 | portable player | $1800 | 1.9 W | +27 dB | Comfortable faint hiss |
| Topping L30 II | desktop amplifier | $130 | 1.8 W | +26 dB | Comfortable |
| Fiio K9 Pro | desktop DAC/amp | $380 | 1.2 W | +25 dB | Comfortable |
| Schiit Magni+ | desktop amplifier | $109 | 1.1 W | +24 dB | Comfortable |
| Fiio K7 | desktop DAC/amp | $180 | 1.1 W | +24 dB | Comfortable |
| Geshelli Archel Pro | desktop amplifier | $200 | 997 mW | +24 dB | Comfortable |
| Schiit Magni Heresy | desktop amplifier | $100 | 911 mW | +24 dB | Comfortable |
| SMSL SH-9 | desktop amplifier | $150 | 876 mW | +23 dB | Comfortable |
| JDS Labs Atom+ (2nd gen) | desktop amplifier | $100 | 665 mW | +22 dB | Comfortable |
| iFi Zen CAN | desktop amplifier | $200 | 665 mW | +22 dB | Comfortable |
| HiBy R6 Pro II | portable player | $750 | 453 mW | +21 dB | Comfortable |
| FiiO KA17 | USB dongle | $150 | 396 mW | +20 dB | Comfortable |
| FiiO M11S | portable player | $500 | 395 mW | +20 dB | Comfortable |
| FiiO BTR17 | Bluetooth receiver | $200 | 381 mW | +20 dB | Comfortable |
| Astell&Kern SP3000 | portable player | $3700 | 361 mW | +20 dB | Comfortable |
| FiiO KA13 | USB dongle | $80 | 319 mW | +19 dB | Comfortable |
| Qudelix T71 | Bluetooth receiver | $200 | 242 mW | +18 dB | Comfortable |
| Astell&Kern SR35 | portable player | $800 | 242 mW | +18 dB | Comfortable |
| FiiO BTR15 | Bluetooth receiver | $110 | 194 mW | +17 dB | Comfortable |
| FiiO BTR7 | Bluetooth receiver | $200 | 183 mW | +17 dB | Comfortable |
| Questyle M15 | USB dongle | $250 | 180 mW | +17 dB | Comfortable |
| Sony NW-WM1AM2 | portable player | $1400 | 149 mW | +16 dB | Comfortable |
| Hidizs S9 Pro | USB dongle | $75 | 144 mW | +16 dB | Comfortable |
| Qudelix 5K | Bluetooth receiver | $110 | 135 mW | +15 dB | Comfortable |
| Schiit Vali 2+ | desktop amplifier | $200 | 133 mW | +15 dB | Comfortable audible hiss |
| Moondrop Dawn Pro | USB dongle | $60 | 131 mW | +15 dB | Comfortable |
| iBasso DC04 Pro | USB dongle | $90 | 131 mW | +15 dB | Comfortable |
| Shanling UP5 | Bluetooth receiver | $130 | 131 mW | +15 dB | Comfortable |
| Truthear SHIO | USB dongle | $70 | 121 mW | +15 dB | Comfortable |
| FiiO KA11 | USB dongle | $30 | 113 mW | +15 dB | Comfortable |
| ddHiFi TC44 Pro | USB dongle | $110 | 109 mW | +14 dB | Comfortable |
| Shanling UA5 | Bluetooth receiver | $220 | 102 mW | +14 dB | Comfortable |
| Tempotec Sonata BHD Pro | USB dongle | $40 | 74 mW | +13 dB | Comfortable |
| iBasso DC03 Pro | USB dongle | $60 | 67 mW | +12 dB | Comfortable |
| EarStudio ES100 MK2 | Bluetooth receiver | $90 | 35 mW | +9 dB | Enough |
| Generic CX31993 dongles | USB dongle | $12 | 34 mW | +9 dB | Enough faint hiss |
| Sony NW-A306 | portable player | $350 | 28 mW | +9 dB | Enough faint hiss |
| Apple USB-C dongle (US) | USB dongle | $9 | 16 mW | +6 dB | Enough faint hiss |
| Apple USB-C dongle (EU) | USB dongle | $9 | 8.2 mW | +3 dB | Enough faint hiss |
Hiss. At 106.1 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 14 dB SPL in these headphones — clearly audible in quiet passages. The hiss calculator lets you check your own amplifier's noise figure.
62Ω · 93.0 dB/mW · Moderate
See requirements →62Ω · 93.0 dB/mW · Moderate
See requirements →62Ω · 93.0 dB/mW · Moderate
See requirements →250Ω · 100.0 dB/mW · Moderate
See requirements →50Ω · 93.0 dB/mW · Moderate
See requirements →50Ω · 93.0 dB/mW · Moderate
See requirements →Or open the comparison tool to put any two models side by side, or browse all 316.