The Audeze LCD-2 Classic is 70Ω with a sensitivity of 101.0 dB/mW, which is 112.5 dB/V. To reach 100 dB SPL — genuinely loud, louder than most people listen — it needs 0.79 mW, or 0.24 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 | 0.03 mW | 42 mV | 0.6 mA |
| 95 dB SPL | normal listening | 0.25 mW | 0.13 V | 1.9 mA |
| 100 dB SPL | loud listening | 0.79 mW | 0.24 V | 3.4 mA |
| 105 dB SPL | very loud | 2.5 mW | 0.42 V | 6.0 mA |
| 110 dB SPL | peaks on dynamic music | 7.9 mW | 0.75 V | 10.7 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 70Ω. “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 70Ω | Headroom | Verdict |
|---|---|---|---|---|---|
| Schiit Ragnarok 2 | desktop amplifier | $1500 | 12.8 W | +42 dB | Comfortable |
| Chord Hugo TT 2 | desktop amplifier | $5000 | 5.0 W | +38 dB | Comfortable |
| Burson Soloist 3X GT | desktop amplifier | $1500 | 4.5 W | +37 dB | Comfortable |
| Ferrum OOR | desktop amplifier | $1800 | 4.4 W | +37 dB | Comfortable |
| Schiit Mjolnir 3 | desktop amplifier | $800 | 4.2 W | +37 dB | Comfortable audible hiss |
| Wells Audio Milo | desktop amplifier | $2500 | 3.8 W | +37 dB | Comfortable |
| Schiit Asgard 3 | desktop amplifier | $250 | 3.5 W | +36 dB | Comfortable |
| Topping A90 Discrete | desktop amplifier | $400 | 3.2 W | +36 dB | Comfortable |
| Topping A90 | desktop amplifier | $500 | 3.1 W | +36 dB | Comfortable |
| Headamp GS-X Mini | desktop amplifier | $1400 | 2.9 W | +36 dB | Comfortable |
| SMSL HO200 | desktop amplifier | $300 | 2.2 W | +34 dB | Comfortable |
| JDS Labs Element III MK2 | desktop DAC/amp | $350 | 2.2 W | +34 dB | Comfortable |
| iFi iCAN Pro | desktop amplifier | $600 | 2.1 W | +34 dB | Comfortable audible hiss |
| Cayin HA-6A | desktop amplifier | $1800 | 1.9 W | +34 dB | Comfortable audible hiss |
| FiiO M17 | portable player | $1800 | 1.7 W | +33 dB | Comfortable faint hiss |
| Topping L30 II | desktop amplifier | $130 | 1.6 W | +33 dB | Comfortable |
| Fiio K9 Pro | desktop DAC/amp | $380 | 1.1 W | +32 dB | Comfortable |
| Schiit Magni+ | desktop amplifier | $109 | 1.0 W | +31 dB | Comfortable |
| Fiio K7 | desktop DAC/amp | $180 | 996 mW | +31 dB | Comfortable |
| Geshelli Archel Pro | desktop amplifier | $200 | 899 mW | +31 dB | Comfortable |
| Schiit Magni Heresy | desktop amplifier | $100 | 828 mW | +30 dB | Comfortable |
| SMSL SH-9 | desktop amplifier | $150 | 801 mW | +30 dB | Comfortable |
| JDS Labs Atom+ (2nd gen) | desktop amplifier | $100 | 627 mW | +29 dB | Comfortable |
| iFi Zen CAN | desktop amplifier | $200 | 627 mW | +29 dB | Comfortable |
| HiBy R6 Pro II | portable player | $750 | 418 mW | +27 dB | Comfortable faint hiss |
| FiiO KA17 | USB dongle | $150 | 366 mW | +27 dB | Comfortable faint hiss |
| FiiO M11S | portable player | $500 | 362 mW | +27 dB | Comfortable faint hiss |
| FiiO BTR17 | Bluetooth receiver | $200 | 349 mW | +26 dB | Comfortable faint hiss |
| Astell&Kern SP3000 | portable player | $3700 | 332 mW | +26 dB | Comfortable faint hiss |
| FiiO KA13 | USB dongle | $80 | 292 mW | +26 dB | Comfortable faint hiss |
| Qudelix T71 | Bluetooth receiver | $200 | 223 mW | +24 dB | Comfortable faint hiss |
| Astell&Kern SR35 | portable player | $800 | 223 mW | +24 dB | Comfortable faint hiss |
| FiiO BTR15 | Bluetooth receiver | $110 | 176 mW | +23 dB | Comfortable faint hiss |
| FiiO BTR7 | Bluetooth receiver | $200 | 167 mW | +23 dB | Comfortable faint hiss |
| Questyle M15 | USB dongle | $250 | 166 mW | +23 dB | Comfortable faint hiss |
| Sony NW-WM1AM2 | portable player | $1400 | 137 mW | +22 dB | Comfortable faint hiss |
| Hidizs S9 Pro | USB dongle | $75 | 128 mW | +22 dB | Comfortable faint hiss |
| Schiit Vali 2+ | desktop amplifier | $200 | 125 mW | +22 dB | Comfortable audible hiss |
| Qudelix 5K | Bluetooth receiver | $110 | 122 mW | +22 dB | Comfortable faint hiss |
| Moondrop Dawn Pro | USB dongle | $60 | 119 mW | +22 dB | Comfortable faint hiss |
| iBasso DC04 Pro | USB dongle | $90 | 119 mW | +22 dB | Comfortable faint hiss |
| Shanling UP5 | Bluetooth receiver | $130 | 119 mW | +22 dB | Comfortable faint hiss |
| Truthear SHIO | USB dongle | $70 | 110 mW | +21 dB | Comfortable |
| FiiO KA11 | USB dongle | $30 | 103 mW | +21 dB | Comfortable faint hiss |
| ddHiFi TC44 Pro | USB dongle | $110 | 99 mW | +21 dB | Comfortable faint hiss |
| Shanling UA5 | Bluetooth receiver | $220 | 93 mW | +21 dB | Comfortable faint hiss |
| Tempotec Sonata BHD Pro | USB dongle | $40 | 67 mW | +19 dB | Comfortable faint hiss |
| iBasso DC03 Pro | USB dongle | $60 | 61 mW | +19 dB | Comfortable faint hiss |
| EarStudio ES100 MK2 | Bluetooth receiver | $90 | 32 mW | +16 dB | Comfortable faint hiss |
| Generic CX31993 dongles | USB dongle | $12 | 31 mW | +16 dB | Comfortable audible hiss |
| Sony NW-A306 | portable player | $350 | 26 mW | +15 dB | Comfortable faint hiss |
| Apple USB-C dongle (US) | USB dongle | $9 | 15 mW | +13 dB | Comfortable faint hiss |
| Apple USB-C dongle (EU) | USB dongle | $9 | 7.4 mW | +10 dB | Enough faint hiss |
Hiss. At 112.5 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 21 dB SPL in these headphones — clearly audible in quiet passages. The hiss calculator lets you check your own amplifier's noise figure.
70Ω · 101.0 dB/mW · Easy
See requirements →32Ω · 110.0 dB/mW · Easy
See requirements →110Ω · 101.0 dB/mW · Easy
See requirements →35Ω · 98.0 dB/mW · Easy
See requirements →14Ω · 94.0 dB/mW · Easy
See requirements →36Ω · 98.0 dB/mW · Easy
See requirements →Or open the comparison tool to put any two models side by side, or browse all 316.