The Beyerdynamic DT 1990 PRO MK II is 30Ω with a sensitivity of 94.0 dB/mW, which is 109.2 dB/V. To reach 100 dB SPL — genuinely loud, louder than most people listen — it needs 4.0 mW, or 0.35 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 280 sources in the database, 254 have at least 10 dB of headroom and another 26 have enough. The cheapest portable source that does the job is the Apple USB-C dongle (US) at $9.
Sensitivity here is in dB per milliwatt. Why the unit matters.
Beyerdynamic publishes this directly as 94 dBSPL (1mW/500Hz), per milliwatt, so nothing was converted.
Source: north-america.beyerdynamic.com. How this data was built.
| As it is labelled | As printed | Tolerance | Standard |
|---|---|---|---|
| Headphone frequency response | 5-40,000 Hz | not printed | not printed |
Beyerdynamic prints 5-40,000 Hz for the Beyerdynamic DT 1990 PRO MK II, under the heading “Headphone frequency response”. Source: north-america.beyerdynamic.com.
No tolerance is printed with it, so “5-40,000 Hz” says nothing about how loud this headphone actually is at 5 Hz.
Only what the maker printed; maker by maker.
| Level | What it is | Power | Voltage | Current |
|---|---|---|---|---|
| 85 dB SPL | quiet background listening | 0.13 mW | 61 mV | 2.0 mA |
| 95 dB SPL | normal listening | 1.3 mW | 0.19 V | 6.5 mA |
| 100 dB SPL | loud listening | 4.0 mW | 0.35 V | 11.5 mA |
| 105 dB SPL | very loud | 13 mW | 0.61 V | 20.5 mA |
| 110 dB SPL | peaks on dynamic music | 40 mW | 1.09 V | 36.4 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 30Ω 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 30Ω | Headroom | Verdict |
|---|---|---|---|---|---|
| FiiO KA11 | USB dongle | $29 | 202 mW | +17 dB | Comfortable |
| Tanchjim Stargate II | USB dongle | $40 | 75 mW | +13 dB | Comfortable |
| ddHiFi TC35AL | USB dongle | $46 | 197 mW | +17 dB | Comfortable |
| ddHiFi TC35Air | USB dongle | $46 | 197 mW | +17 dB | Comfortable |
| Fosi Audio N3 | Bluetooth receiver | $50 | 129 mW | +15 dB | Comfortable |
| Hidizs SD2 | USB dongle | $50 | 66 mW | +12 dB | Comfortable |
| FiiO BTR13 | Bluetooth receiver | $59 | 101 mW | +14 dB | Comfortable |
| iFi GO link | USB dongle | $59 | 66 mW | +12 dB | Comfortable |
| Kiwi Ears Allegro Pro | USB dongle | $60 | 64 mW | +12 dB | Comfortable |
| ddHiFi TC35Pro (Mountain2) | USB dongle | $66 | 61 mW | +12 dB | Comfortable |
| iBasso DC03 Pro | USB dongle | $69 | 92 mW | +14 dB | Comfortable |
| DUNU DTC 480 | USB dongle | $70 | 61 mW | +12 dB | Comfortable |
| EPZ TP35 Pro | USB dongle | $70 | 105 mW | +14 dB | Comfortable |
| Tanchjim Space | USB dongle | $70 | 117 mW | +15 dB | Comfortable |
| Truthear SHIO | USB dongle | $70 | 117 mW | +15 dB | Comfortable |
Hiss. At 109.2 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 17 dB SPL in these headphones — clearly audible in quiet passages. Check your own source.
Output impedance. At 30Ω these want a source output impedance below 3.75Ω to satisfy the one-eighth rule; 35 of the 192 sources that publish one miss it. Check yours here.
30Ω · 95.0 dB/mW · Easy
See requirements →32Ω · 96.0 dB · Easy
See requirements →32Ω · 100.0 dB/mW · Easy
See requirements →47Ω · 96.0 dB/mW · Easy
See requirements →47Ω · 96.0 dB · Easy
See requirements →32Ω · 94.1 dB/mW · Easy
See requirements →Compared with its stablemates: vs Custom One Pro Plus · vs DT 880 Edition (600Ω) · vs DT 990 Edition (600Ω) · vs T1 3rd Gen (32Ω) · vs T5 (3rd Generation).