MACH 20 vs MACH 80: which needs more amplifier?

The Westone MACH 20 is 96Ω at 110.0 dB (no reference unit printed); the Westone MACH 80 is 66Ω at 104.0 dB (no reference unit printed). This page covers what they ask of an amplifier, not how they sound.

The MACH 80 needs 6.0 dB more than the MACH 20 to reach the same loudness — 0.40 mW against 0.10 mW.

The numbers that decide it

SpecificationMACH 20MACH 80
Impedance96 Ω66 Ω
Sensitivity110.0 dB104.0 dB
Sensitivity (voltage)120.2 dB/V115.8 dB/V
Power for 100 dB0.10 mW0.40 mW
Voltage for 100 dB98 mV0.16 V
Current for 100 dB1.0 mA2.5 mA
Highest source impedance
that leaves them alone (one-eighth rule)
12.00 Ω8.25 Ω
Sources that reach 100 dB
out of 280
280280

One caution before reading the rows. Westone MACH 20 and Westone MACH 80 printed a decibel figure with no reference unit, so this page reads it as per milliwatt. If it is really per volt, each of them needs far more than the table says. Why the two readings differ by so much.

Where the two part company

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.

16 sources are low enough in output impedance for the MACH 20 under the one-eighth rule but not for the MACH 80 (Zoom AMS-22, Arturia MiniFuse 2, Arturia MiniFuse 1, 13 more).

280 of the 280 sources here reach 100 dB on both.

What each one needs from 80 to 105 dB

The MACH 80 is more demanding than 51% of the 567 non-electrostatic models in this database; the MACH 20 than 31%.

dB SPLMACH 20 powerMACH 20 voltageMACH 80 powerMACH 80 voltage
801.0 µW10 mV4.0 µW16 mV
853.2 µW17 mV0.01 mW29 mV
900.01 mW31 mV0.04 mW51 mV
950.03 mW55 mV0.13 mW91 mV
1000.10 mW98 mV0.40 mW0.16 V
1050.32 mW0.17 V1.3 mW0.29 V

The cheapest source that satisfies both

SourcePriceHeadroom, MACH 20Headroom, MACH 80Output impedanceNoise
JadeAudio JA11$2020.0 dB15.6 dB0.5 Ω1.7 µV
FiiO KA11$2928.3 dB23.9 dB0.7 Ω1.7 µV
FiiO BTR11$3619.9 dB15.6 dB0.5 Ω8.0 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 20.0 dB of headroom on the MACH 20 and 15.6 dB on the MACH 80, its output impedance is 0.5 Ω against a one-eighth limit of 12.00 Ω and 8.25 Ω, and its noise figure puts the hiss floor 15 dB and 20 dB below the 20 dB SPL this site treats as the point where a quiet room stops hiding it.

Try any other source.

What each sheet prints, and what it is worth

ModelAs printedToleranceStandard
MACH 2020Hz – 18kHznot printednot printed
MACH 805Hz – 22kHznot printednot printed

Westone prints 20Hz – 18kHz for the MACH 20 and 5Hz – 22kHz for the MACH 80.

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 pages in full

Both have a page of their own. In full: Westone MACH 20 and Westone MACH 80. 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.

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