Westone MACH 80: how much amplifier do you need?

The Westone MACH 80 is 66Ω. Its maker prints a sensitivity of 104.0 dB and never says whether that is per milliwatt or per volt, so this page reads it as per milliwatt — on that reading it needs 0.40 mW to reach 100 dB SPL, or 0.16 V across the drivers. If the figure is really per volt, it needs far more.

That puts it in the easy category. A phone, a laptop headphone jack or the cheapest USB dongle will drive it to painful levels. Of the 280 sources in the database, 280 have at least 10 dB of headroom and another 0 have enough. The cheapest portable source that does the job is the Apple USB-C dongle (US) at $9.

The two numbers that decide everything

Impedance66 Ω
Sensitivity (printed with no reference unit)104.0 dB
Sensitivity (voltage) (if the figure is per milliwatt)115.8 dB/V
Power for 100 dB SPL (if the figure is per milliwatt)0.40 mW
Voltage for 100 dB SPL (if the figure is per milliwatt)0.16 V
TypeOver-ear
Easy to drive — anything will do it
All 280 sources at 100 dB SPL into 66Ω
Comfortable 280Enough 0Marginal 0Not enough 0
Cheapest portable source that does it
$9 · USB dongle · +16 dB headroom
Cheapest desktop amp with 10 dB to spare
$75 · desktop DAC/amp · +23 dB headroom

This maker printed a decibel figure and no reference unit, so the number above is shown exactly as printed. Everything below reads it as per milliwatt, which is the commoner convention on a sheet that omits the unit — if it is really per volt, this headphone is about 12 dB harder to drive than the rest of this page assumes. The converter explains the difference.

Where this sensitivity figure comes from

Westone publishes a sensitivity of 104 dB and does not state whether that is per milliwatt or per volt — the spec sheet simply stops at the number.

Both readings are given here so you can judge for yourself. If that 104 dB is per milliwatt, the figures on this page are right as they stand. If it is per volt, the real sensitivity is 92.2 dB/mW — 12 dB lower at 66Ω — and everything above understates what these need by that much. The per-milliwatt reading is the one shown, because it is the more common convention on a spec sheet that omits the unit; treat it as an indication rather than a specification.

Westone prints the impedance as 66 Ohms @1kHz, not as a bare number. Everything on this page is calculated with the nominal 66Ω, and the rest of that line is quoted here rather than tidied away, because how a figure is qualified is part of the specification too.

Source: westoneaudio.com. How this data was built.

What is printed there, and what it is worth

As it is labelledAs printedToleranceStandard
FREQ RESPONSE5Hz – 22kHznot printednot printed

Westone prints 5Hz – 22kHz for the Westone MACH 80, under the heading “FREQ RESPONSE”. Source: westoneaudio.com.

No tolerance is printed with it, so “5Hz – 22kHz” says nothing about how loud this headphone actually is at 5 Hz.

Only what the maker printed; maker by maker.

Power, voltage and current by listening level

LevelWhat it isPowerVoltageCurrent
85 dB SPLquiet background listening0.01 mW29 mV0.4 mA
95 dB SPLnormal listening0.13 mW91 mV1.4 mA
100 dB SPLloud listening0.40 mW0.16 V2.5 mA
105 dB SPLvery loud1.3 mW0.29 V4.4 mA
110 dB SPLpeaks on dynamic music4.0 mW0.51 V7.8 mA

Most people listen between 75 and 85 dB; the 100 dB row leaves room for peaks.

The cheapest sources that drive them with room to spare

The 15 cheapest of the 280 sources here that reach 100 dB SPL into 66Ω 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.

SourceTypePricePower into 66ΩHeadroomVerdict
FiiO SnowSky Tiny AUSB dongle$2217 mW+16 dBComfortable
FiiO SnowSky Tiny BUSB dongle$2217 mW+16 dBComfortable
Tanchjim Stargate IIUSB dongle$4036 mW+20 dBComfortable
ddHiFi TC35ALUSB dongle$46102 mW+24 dBComfortable
ddHiFi TC35AirUSB dongle$46102 mW+24 dBComfortable
Fosi Audio N3Bluetooth receiver$5067 mW+22 dBComfortable
Hidizs SD2USB dongle$5034 mW+19 dBComfortable
FiiO BTR13Bluetooth receiver$5948 mW+21 dBComfortable
iFi GO linkUSB dongle$5937 mW+20 dBComfortable
Kiwi Ears Allegro ProUSB dongle$6033 mW+19 dBComfortable
ddHiFi TC35Pro (Mountain2)USB dongle$6632 mW+19 dBComfortable
iBasso DC03 ProUSB dongle$6948 mW+21 dBComfortable
DUNU DTC 480USB dongle$7032 mW+19 dBComfortable
EPZ TP35 ProUSB dongle$7054 mW+21 dBComfortable
Tanchjim SpaceUSB dongle$7061 mW+22 dBComfortable

The three ways a source goes wrong

Hiss. At 115.8 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 24 dB SPL in these headphones — clearly audible in quiet passages. Check your own source.

Output impedance. At 66Ω these want a source output impedance below 8.25Ω to satisfy the one-eighth rule; 34 of the 192 sources that publish one miss it. Check yours here.

Similar headphones

Compared with its stablemates: vs MACH 10 · vs MACH 20 · vs MACH 60 · vs Pro X10.

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