The Sony NW-WM1ZM2 is a portable player at $3700. It delivers 30 mW into 32Ω and 3.2 mW into 300Ω, which ranks it 265 of 280 for raw power among the sources in this database.
Measured at 100 dB SPL it has comfortable headroom on 422 of the 567 dynamic and planar headphones catalogued here, enough but not generous on 102, only marginal on 28 and not enough power for 15. Power is published at 16Ω; the rest of the table is derived from those figures. Output impedance is not published. Output noise is not published, so the hiss estimate cannot be run.
The manufacturer publishes 60 mW into 16Ω. Everything else in the table above is worked out from those figures, and this table says which is which.
The balanced output is rated separately: 125 mW into 32Ω through the 4.4mm jack.
Derivation holds output voltage steady between and beyond the published loads rather than output power, because that is what an amplifier actually does. The full method is written up here.
Source: sony-mea.com.
| Load | Power | Status | How it was arrived at |
|---|---|---|---|
| 16 Ω | 60 mW | Published | the manufacturer publishes this figure at this exact load |
| 32 Ω | 30 mW | Derived | beyond the published loads, holding output voltage constant — which understates rather than flatters |
| 150 Ω | 6.4 mW | Derived | beyond the published loads, holding output voltage constant — which understates rather than flatters |
| 300 Ω | 3.2 mW | Derived | beyond the published loads, holding output voltage constant — which understates rather than flatters |
| 600 Ω | 1.6 mW | Derived | beyond the published loads, holding output voltage constant — which understates rather than flatters |
Ordered from easiest to hardest to drive. Headroom is measured at 100 dB SPL, which is louder than almost anyone listens — a small negative number means the source still plays loud, just without reserve for peaks.
These figures come from each manufacturer's own sensitivity rating. A handful of planars — the HiFiMAN Susvara and the Abyss AB-1266 in particular — are widely reported to need far more than their published sensitivity implies, so treat a bare pass on those as optimistic rather than settled.
| Headphone | Impedance | Sensitivity | Needs | Headroom | Verdict |
|---|---|---|---|---|---|
| Shure SE846 | 9 Ω | 114.0 dB/mW | 0.04 mW | +29 dB | Comfortable |
| 64 Audio U12t | 12.6 Ω | 108.0 dB/mW | 0.16 mW | +25 dB | Comfortable |
| Shure SE215 | 17 Ω | 107.0 dB/mW | 0.20 mW | +25 dB | Comfortable |
| Moondrop Aria | 32 Ω | 107.1 dB/mW | 0.19 mW | +22 dB | Comfortable |
| Audeze LCD-X 2021 | 20 Ω | 103.0 dB/mW | 0.50 mW | +20 dB | Comfortable |
| Truthear Hexa | 20.5 Ω | 103.1 dB/mW | 0.49 mW | +20 dB | Comfortable |
| Sennheiser IE 200 | 18 Ω | 101.6 dB/mW | 0.69 mW | +19 dB | Comfortable |
| Sony MDR-7506 | 63 Ω | 106.0 dB/mW | 0.25 mW | +18 dB | Comfortable |
| Meze 99 Classics | 32 Ω | 103.0 dB/mW | 0.50 mW | +18 dB | Comfortable |
| Focal Clear MG | 55 Ω | 104.0 dB/mW | 0.40 mW | +16 dB | Comfortable |
| Philips SHP9500 | 32 Ω | 101.0 dB | 0.79 mW | +16 dB | Comfortable |
| Focal Utopia | 80 Ω | 104.0 dB/mW | 0.40 mW | +15 dB | Comfortable |
| Meze Empyrean | 32 Ω | 100.0 dB | 1.0 mW | +15 dB | Comfortable |
| Campfire Audio Andromeda 2020 | 9 Ω | 94.0 dB | 4.0 mW | +9 dB | Enough |
| Etymotic ER2SE | 15 Ω | 96.0 dB/mW | 2.5 mW | +14 dB | Comfortable |
| AKG K371 | 32 Ω | 99.1 dB/mW | 1.2 mW | +14 dB | Comfortable |
| Audio-Technica ATH-M50X | 38 Ω | 99.0 dB/mW | 1.3 mW | +13 dB | Comfortable |
| Beyerdynamic DT 900 Pro X | 48 Ω | 100.0 dB/mW | 1.0 mW | +13 dB | Comfortable |
| Audeze LCD-2 Classic | 70 Ω | 101.0 dB/mW | 0.79 mW | +12 dB | Comfortable |
| Grado SR80x | 38 Ω | 98.0 dB/mW | 1.6 mW | +12 dB | Comfortable |
| Sennheiser HD 560S | 120 Ω | 100.8 dB/mW | 0.83 mW | +10 dB | Enough |
| HiFiMAN Edition XS | 18 Ω | 92.0 dB | 6.3 mW | +9 dB | Enough |
| HiFiMAN Arya Stealth | 32 Ω | 94.0 dB | 4.0 mW | +9 dB | Enough |
| Dan Clark Audio AEON 2 Closed | 13 Ω | 90.0 dB/mW | 10 mW | +7 dB | Enough |
| Audeze LCD-5 | 14 Ω | 90.0 dB/mW | 10 mW | +7 dB | Enough |
| Beyerdynamic DT 1990 Pro (250Ω) | 250 Ω | 102.0 dB/mW | 0.63 mW | +8 dB | Enough |
| HiFiMAN HE400se | 25 Ω | 91.0 dB | 7.9 mW | +7 dB | Enough |
| HiFiMAN Sundara | 32 Ω | 92.0 dB | 6.3 mW | +7 dB | Enough |
| Dan Clark Audio Stealth | 23 Ω | 90.0 dB/mW | 10 mW | +6 dB | Enough |
| Fostex T50RP MK3 | 50 Ω | 92.0 dB/mW | 6.3 mW | +5 dB | Enough |
| AKG K702 | 62 Ω | 92.9 dB/mW | 5.1 mW | +5 dB | Enough |
| ZMF Verite Closed | 300 Ω | 99.0 dB/mW | 1.3 mW | +4 dB | Enough |
| Sennheiser HD 650 | 300 Ω | 97.8 dB/mW | 1.7 mW | +3 dB | Marginal |
| Sennheiser HD 800S | 300 Ω | 96.8 dB/mW | 2.1 mW | +2 dB | Marginal |
| Beyerdynamic DT 770 Pro (250Ω) | 250 Ω | 96.0 dB | 2.5 mW | +2 dB | Marginal |
| Audio-Technica ATH-R70X | 470 Ω | 98.0 dB/mW | 1.6 mW | +1 dB | Marginal |
| ZMF Atrium | 300 Ω | 96.0 dB/mW | 2.5 mW | +1 dB | Marginal |
| Abyss AB-1266 Phi TC | 50 Ω | 88.0 dB/mW | 16 mW | +1 dB | Marginal |
| Sennheiser HD 600 | 300 Ω | 91.8 dB/mW | 6.6 mW | -3 dB | Not enough |
| HiFiMAN Susvara | 60 Ω | 83.0 dB | 50 mW | -5 dB | Not enough |
The manufacturer does not publish an output noise figure for this source, so the hiss estimate that runs on every other page here cannot be run on this one. Rather than substitute a plausible number, this page leaves the question open.
If you know the noise figure from a measurement you trust, the hiss calculator takes it directly and tells you where that noise lands in your own in-ears.
The manufacturer does not publish an output impedance for this source. That is the one number that decides whether it leaves your headphones alone or acts as a tone control, so its absence matters more than it looks: without it, nothing here can tell you how this source will behave with a multi-driver in-ear.
If you find a measured figure you trust, the checker will work out the consequence for any headphone.
| Product | Price |
|---|---|
| Sony NW-WM1AM2 | $1399 |
| Sony NW-WM1ZM2 | $3700 |
On every figure Sony publishes for this headphone output, the Sony NW-WM1ZM2 is identical to the Sony NW-WM1AM2. Each of them states power at 16 Ω — and each states the same values.
They do not cost the same. The spread across the 2 of them is $2301, and none of that difference is visible in the figures above.
Identical published figures do not mean identical products. A spec sheet for a headphone output covers power, output impedance and noise. It says nothing about the converter, the inputs, the case, the battery, the volume control or how any of it sounds, and those are real differences that cost real money. What this section says is narrower and worth saying anyway: if you are choosing between these on what the maker printed about the headphone jack, there is nothing to choose.
15 groups of products in this database share a spec sheet this way, 36 products in all.
| Source | Type | Price | Into 300 Ω | Output impedance | Output noise |
|---|---|---|---|---|---|
| FiiO SnowSky Tiny B | USB dongle | $22 | 3.6 mW | 1.0 Ω | not published |
| FiiO KA11 | USB dongle | $29 | 22 mW | 0.7 Ω | 1.7 µV |
| Tanchjim Stargate II | USB dongle | $40 | 8.0 mW | not published | not published |
Of the 280 sources here, 217 do everything the Sony NW-WM1ZM2 does as a headphone output: reach 100 dB on every headphone it reaches. The cheapest of them is the FiiO SnowSky Tiny B at $22, against this one’s $3700 — $3678 less, and a USB dongle rather than a portable player.
The cheaper one also publishes an output impedance, which the Sony NW-WM1ZM2 does not — so on the paperwork it is ahead, not merely level.
This counts a headphone output and nothing else. Inputs, converters, microphone preamps, balanced outputs, the volume control, the case and the warranty are all outside it, and any of them can be the reason to buy the dearer box. What the count does say is that the three numbers a maker can be held to do not separate them.
$3700 · 340 mW into 32Ω · 0.7 Ω out
Compare →$3899 · 180 mW into 32Ω · 0.2 Ω out
Compare →$2959 · 520 mW into 32Ω · 1 Ω out
Compare →$1999 · 250 mW into 32Ω · 0.6 Ω out
Compare →$1999 · 225 mW into 32Ω · 1 Ω out
Compare →$1799 · 500 mW into 32Ω · 1 Ω out
Compare →Worked out in advance against its closest rivals: vs Astell&Kern SP3000 · vs Luxury & Precision P6 Pro · vs Shanling M9 Plus · vs Sony NW-A306 · vs Sony NW-ZX707. Each of those pages lists the headphones that tell the two apart.
Or put any two side by side in the source comparison tool, or run your own headphones through the amplifier matcher. Or see every Sony source in the database, and how much of what this site says about them came from Sony’s own documents.