The Audio-Technica ATH-R70X is 470Ω at 98.0 dB/mW; the Beyerdynamic DT 990 Pro (250Ω) is 250Ω at 96.0 dB (no reference unit printed). This page covers what they ask of an amplifier, not how they sound.
The Beyerdynamic DT 990 Pro (250Ω) needs 2.0 dB more than the Audio-Technica ATH-R70X to reach the same loudness — 2.5 mW against 1.6 mW.
| Specification | Audio-Technica ATH-R70X | Beyerdynamic DT 990 Pro (250Ω) |
|---|---|---|
| Impedance | 470 Ω | 250 Ω |
| Sensitivity | 98.0 dB/mW | 96.0 dB |
| Sensitivity (voltage) | 101.3 dB/V | 102.0 dB/V |
| Power for 100 dB | 1.6 mW | 2.5 mW |
| Voltage for 100 dB | 0.86 V | 0.79 V |
| Current for 100 dB | 1.8 mA | 3.2 mA |
| Highest source impedance that leaves them alone (one-eighth rule) | 58.75 Ω | 31.25 Ω |
| Sources that reach 100 dB out of 280 | 277 | 277 |
One caution before reading the rows. Beyerdynamic DT 990 Pro (250Ω) printed a decibel figure with no reference unit, so this page reads it as per milliwatt. If it is really per volt, that model needs far more than the table says. Why the two readings differ by so much.
Every source in the database that drives one of them drives the other. On power, the choice between these two changes nothing about what amplifier you need.
14 sources are low enough in output impedance for the Audio-Technica ATH-R70X under the one-eighth rule but not for the Beyerdynamic DT 990 Pro (250Ω) (Audient EVO 4, ART HeadAmp 4 Pro, Focusrite Scarlett Solo 4th gen, 11 more).
277 of the 280 sources here reach 100 dB on both.
The Audio-Technica ATH-R70X is more demanding than 96% of the 567 non-electrostatic models in this database; the Beyerdynamic DT 990 Pro (250Ω) than 95%.
| dB SPL | Audio-Technica ATH-R70X power | Audio-Technica ATH-R70X voltage | Beyerdynamic DT 990 Pro (250Ω) power | Beyerdynamic DT 990 Pro (250Ω) voltage |
|---|---|---|---|---|
| 80 | 0.02 mW | 86 mV | 0.03 mW | 79 mV |
| 85 | 0.05 mW | 0.15 V | 0.08 mW | 0.14 V |
| 90 | 0.16 mW | 0.27 V | 0.25 mW | 0.25 V |
| 95 | 0.50 mW | 0.49 V | 0.79 mW | 0.45 V |
| 100 | 1.6 mW | 0.86 V | 2.5 mW | 0.79 V |
| 105 | 5.0 mW | 1.53 V | 7.9 mW | 1.41 V |
| Source | Price | Headroom, Audio-Technica ATH-R70X | Headroom, Beyerdynamic DT 990 Pro (250Ω) | Output impedance | Noise |
|---|---|---|---|---|---|
| JadeAudio JA11 | $20 | 1.1 dB | 1.8 dB | 0.5 Ω | 1.7 µV |
| FiiO KA11 | $29 | 9.5 dB | 10.2 dB | 0.7 Ω | 1.7 µV |
| FiiO BTR11 | $36 | 0.8 dB | 1.6 dB | 0.5 Ω | 8.0 µV |
Of the 280 sources here, 277 reach 100 dB on both. 72 of them also publish an output impedance low enough for both under the one-eighth rule and a noise figure that stays below the audible-hiss threshold with both.
The cheapest of the 72 is the JadeAudio JA11, at $20. It leaves 1.1 dB of headroom on the Audio-Technica ATH-R70X and 1.8 dB on the Beyerdynamic DT 990 Pro (250Ω), its output impedance is 0.5 Ω against a one-eighth limit of 58.75 Ω and 31.25 Ω, and its noise figure puts the hiss floor 34 dB and 33 dB below the 20 dB SPL this site treats as the point where a quiet room stops hiding it.
| Model | As printed | Tolerance | Standard |
|---|---|---|---|
| Audio-Technica ATH-R70X | 5 - 40,000 Hz | not printed | not printed |
| Beyerdynamic DT 990 Pro (250Ω) | 5 - 35.000 Hz | not printed | not printed |
Audio-Technica prints 5 - 40,000 Hz for the ATH-R70X. Beyerdynamic prints 5 - 35.000 Hz for the DT 990 Pro (250Ω).
Neither range has a tolerance printed beside it, so a wider range on one sheet is not deeper bass or more treble.
Not a measurement; maker by maker.
Both have a page of their own. In full: Audio-Technica ATH-R70X and Beyerdynamic DT 990 Pro (250Ω). Each figure on this page is labelled on those pages with where it came from, including the ones Audio-Technica and Beyerdynamic never published — what Audio-Technica publishes and what Beyerdynamic publishes, both counted.