OPPO PM-3
A closed planar that set out to be portable and honest at the same time, and mostly managed it. Measured here on our own bench.
Our take
The PM-3 measures like something built to a brief rather than to a trend: bass is level rather than boosted, the lower mids sit a little back, and there is a clear presence lift around 3 kHz that keeps voices forward. Above 8 kHz it eases off, so it reads as smooth rather than airy — closed planars usually do. It is a headphone that responds well to a small amount of correction rather than a rescue, which is the easiest kind to tune.
Measured by Warren Labs on a miniDSP EARS Pro. The headphone is seated deliberately for the best fit — the way someone who cares about sound adjusts a headphone before they settle in to listen — rather than placed at random, and the published curve is a single real seating chosen by an objective rule, never a blend. Both channels are measured and stored separately; the line drawn here is their average. Raw response, normalized to 0 dB at 1 kHz. An EARS Pro is not an industry reference coupler such as a GRAS 45CA, so read this as a house reference: repeatable against our other EARS Pro measurements, not directly comparable to another lab. Seating repeatability on this bench is not characterized yet, so there is no variance figure to give. Do not read fine treble detail as settled.How we measure →
Common questions
Straight answers — the same ones our measurements support.
Does the OPPO PM-3 need an amp?
No. At 26 Ω and around 102 dB/mW it was designed to run off a phone, and it does. An amp buys headroom, not a different tuning.
Is it still worth buying?
OPPO left the audio business, so it is a used-market proposition now. The measurement is here so you can decide on what it does rather than on nostalgia.
Why does the top octave look rolled off?
Partly the headphone, partly the rig. Above ~8 kHz fixture and seating variance dominate any measurement, so read the top octave as a direction, not a number.
If you like the PM-3
Close on the graph, or a deliberate step in one direction.