The Neumann NDH 30 is 120Ω with a sensitivity of 94.8 dB/mW, which is 104.0 dB/V. To reach 100 dB SPL — genuinely loud, louder than most people listen — it needs 3.3 mW, or 0.63 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. 277 of 280 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. Why the unit matters.
Neumann publishes this as 104 dB SPL (1 kHz / 1 Vrms) (1 kHz at 1 Vrms) — a figure per volt, not per milliwatt. At 120Ω the two differ by 9.2 dB, so the 94.8 dB/mW above is that published number converted, not a different measurement.
This is the conversion that online calculators skip. Quote the per-volt number as if it were per-milliwatt and this headphone looks 9 dB easier to drive than it is — which is roughly the difference between a dongle being enough and not being enough.
Source: neumann.com. How this data was built.
| As it is labelled | As printed | Tolerance | Standard |
|---|---|---|---|
| Frequency Range | 12 ... 34,000 Hz | not printed | not printed |
Neumann prints 12 ... 34,000 Hz for the Neumann NDH 30, under the heading “Frequency Range”. Source: neumann.com.
Neumann labels this row “Frequency Range” on the NDH 30 and “Frequency response” on the NDH 20, in the same house style of table.
No tolerance is printed with it, so “12 ... 34,000 Hz” says nothing about how loud this headphone actually is at 12 Hz.
Only what the maker printed; maker by maker.
| Level | What it is | Power | Voltage | Current |
|---|---|---|---|---|
| 85 dB SPL | quiet background listening | 0.10 mW | 0.11 V | 0.9 mA |
| 95 dB SPL | normal listening | 1.0 mW | 0.35 V | 3.0 mA |
| 100 dB SPL | loud listening | 3.3 mW | 0.63 V | 5.3 mA |
| 105 dB SPL | very loud | 10 mW | 1.12 V | 9.3 mA |
| 110 dB SPL | peaks on dynamic music | 33 mW | 1.99 V | 16.6 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 120Ω 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 120Ω | Headroom | Verdict |
|---|---|---|---|---|---|
| FiiO KA11 | USB dongle | $29 | 54 mW | +12 dB | Comfortable |
| ddHiFi TC35AL | USB dongle | $46 | 56 mW | +12 dB | Comfortable |
| ddHiFi TC35Air | USB dongle | $46 | 56 mW | +12 dB | Comfortable |
| Fosi Audio N3 | Bluetooth receiver | $50 | 37 mW | +10 dB | Comfortable |
| Tempotec Sonata BHD Pro | USB dongle | $60 | 75 mW | +14 dB | Comfortable |
| Tanchjim Space | USB dongle | $70 | 33 mW | +10 dB | Comfortable |
| Truthear SHIO | USB dongle | $70 | 33 mW | +10 dB | Comfortable |
| Aiyima A2 Pro | desktop DAC/amp | $75 | 40 mW | +11 dB | Comfortable |
| Moondrop Dawn Pro | USB dongle | $75 | 33 mW | +10 dB | Comfortable |
| FiiO KA3 | USB dongle | $79 | 35 mW | +10 dB | Comfortable |
| JDS Labs Atom+ (2nd gen) | desktop amplifier | $99 | 558 mW | +22 dB | Comfortable |
| Schiit Magni Heresy | desktop amplifier | $99 | 759 mW | +24 dB | Comfortable |
| ddHiFi TC44 Pro E2 | USB dongle | $99 | 67 mW | +13 dB | Comfortable |
| Creative Sound Blaster X3 | desktop DAC/amp | $100 | 34 mW | +10 dB | Comfortable |
| Fosi Audio SK02 | desktop amplifier | $100 | 51 mW | +12 dB | Comfortable |
Hiss. At 104.0 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 12 dB SPL in these headphones — clearly audible in quiet passages. Check your own source.
Output impedance. At 120Ω these want a source output impedance below 15.00Ω to satisfy the one-eighth rule; 17 of the 192 sources that publish one miss it. Check yours here.
150Ω · 105.8 dB/mW · Easy
See requirements →50Ω · 91.0 dB/mW · Moderate
See requirements →55Ω · 91.4 dB/mW · Moderate
See requirements →55Ω · 91.4 dB/mW · Moderate
See requirements →55Ω · 91.4 dB/mW · Moderate
See requirements →200Ω · 97.0 dB/mW · Moderate
See requirements →Compared with its stablemates: vs NDH 20.