The Westone MACH 10 is 80Ω at 103.0 dB (no reference unit printed); the Westone Pro X10 is 19Ω at 114.0 dB/mW. This page is only about what they ask of an amplifier — not how they sound, which no specification on either sheet can tell you.
The MACH 10 needs 11.0 dB more than the Pro X10 to reach the same loudness — 0.50 mW against 0.04 mW.
| Specification | MACH 10 | Pro X10 |
|---|---|---|
| Impedance | 80 Ω | 19 Ω |
| Sensitivity | 103.0 dB | 114.0 dB/mW |
| Sensitivity (voltage) | 114.0 dB/V | 131.2 dB/V |
| Power for 100 dB | 0.50 mW | 0.04 mW |
| Voltage for 100 dB | 0.20 V | 28 mV |
| Current for 100 dB | 2.5 mA | 1.4 mA |
| Highest source impedance that leaves them alone (one-eighth rule) | 10.00 Ω | 2.38 Ω |
| Sources that reach 100 dB out of 280 | 280 | 280 |
One caution before reading the rows. Westone MACH 10 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.
10 sources are low enough in output impedance for the MACH 10 under the one-eighth rule but not for the Pro X10 (Zoom AMS-22, Arturia MiniFuse 2, Arturia MiniFuse 1, 7 more).
27 sources stay below the audible-hiss threshold with the MACH 10 but cross it with the Pro X10 (Kiwi Ears Allegro Mini, FiiO BTR11, FiiO K11, 24 more).
280 of the 280 sources here reach 100 dB on both. That count is about power only — the output-impedance and hiss lines above are separate questions, and a source can pass this one and fail those.
Each model has a page of its own with the full source list, the hiss estimate and the provenance of every figure above: Westone MACH 10 and Westone Pro X10. Each figure on this page is labelled on those pages with where it came from, including the ones Westone never published — what that maker publishes, counted.