The Audio-Technica ATH-M50xBT2 (wired) is 38Ω at 99.0 dB/mW; the Audio-Technica ATH-M70X is 35Ω at 97.0 dB/mW. This page covers what they ask of an amplifier, not how they sound.
The ATH-M70X needs 2.0 dB more than the ATH-M50xBT2 (wired) to reach the same loudness — 2.0 mW against 1.3 mW.
| Specification | ATH-M50xBT2 (wired) | ATH-M70X |
|---|---|---|
| Impedance | 38 Ω | 35 Ω |
| Sensitivity | 99.0 dB/mW | 97.0 dB/mW |
| Sensitivity (voltage) | 113.2 dB/V | 111.6 dB/V |
| Power for 100 dB | 1.3 mW | 2.0 mW |
| Voltage for 100 dB | 0.22 V | 0.26 V |
| Current for 100 dB | 5.8 mA | 7.6 mA |
| Highest source impedance that leaves them alone (one-eighth rule) | 4.75 Ω | 4.38 Ω |
| Sources that reach 100 dB out of 280 | 280 | 280 |
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.
1 source is low enough in output impedance for the ATH-M50xBT2 (wired) under the one-eighth rule but not for the ATH-M70X (Shanling H5).
1 source stays below the audible-hiss threshold with the ATH-M70X but crosses it with the ATH-M50xBT2 (wired) (Schiit Mjolnir 3).
280 of the 280 sources here reach 100 dB on both.
The ATH-M70X is more demanding than 69% of the 567 non-electrostatic models in this database; the ATH-M50xBT2 (wired) than 62%.
| dB SPL | ATH-M50xBT2 (wired) power | ATH-M50xBT2 (wired) voltage | ATH-M70X power | ATH-M70X voltage |
|---|---|---|---|---|
| 80 | 0.01 mW | 22 mV | 0.02 mW | 26 mV |
| 85 | 0.04 mW | 39 mV | 0.06 mW | 47 mV |
| 90 | 0.13 mW | 69 mV | 0.20 mW | 84 mV |
| 95 | 0.40 mW | 0.12 V | 0.63 mW | 0.15 V |
| 100 | 1.3 mW | 0.22 V | 2.0 mW | 0.26 V |
| 105 | 4.0 mW | 0.39 V | 6.3 mW | 0.47 V |
| Source | Price | Headroom, ATH-M50xBT2 (wired) | Headroom, ATH-M70X | Output impedance | Noise |
|---|---|---|---|---|---|
| JadeAudio JA11 | $20 | 13.0 dB | 11.4 dB | 0.5 Ω | 1.7 µV |
| FiiO KA11 | $29 | 21.3 dB | 19.6 dB | 0.7 Ω | 1.7 µV |
| FiiO BTR11 | $36 | 13.0 dB | 11.4 dB | 0.5 Ω | 8.0 µV |
Of the 280 sources here, 280 reach 100 dB on both. 69 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 69 is the JadeAudio JA11, at $20. It leaves 13.0 dB of headroom on the ATH-M50xBT2 (wired) and 11.4 dB on the ATH-M70X, its output impedance is 0.5 Ω against a one-eighth limit of 4.75 Ω and 4.38 Ω, and its noise figure puts the hiss floor 22 dB and 24 dB below the 20 dB SPL this site treats as the point where a quiet room stops hiding it.
| Model | As printed | Tolerance | Standard |
|---|---|---|---|
| ATH-M50xBT2 (wired) | 15 - 28,000 Hz | not printed | not printed |
| ATH-M70X | 5 - 40,000 Hz | not printed | not printed |
Audio-Technica prints 15 - 28,000 Hz for the ATH-M50xBT2 (wired) and 5 - 40,000 Hz for the ATH-M70X.
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-M50xBT2 (wired) and Audio-Technica ATH-M70X. Every figure on this page comes from what Audio-Technica published, or is derived from it — what that maker publishes, counted.