Oppo PM-3 Headphone Review
Can you make an affordable planar headphone and then can you make it any good?
What is the Oppo PM-3?There is an argument - and one not entirely without merit - that it is easier to make an expensive version of something than it is to make a superficially simpler but more affordable one. If you are building in small volumes with a substantial budget, you can essentially spend your way out of engineering issues because the final price of the product is rather more elastic than building to a specific price point. With a loudspeaker, it is easier to deal with the fundamental limitations of material science by reaching for more exotic (and expensive) materials where countering them at a normal price point requires compromise and ingenuity.
As such, sometimes we have to wait to see how a manufacturer handles the challenge of building something at a terrestrial price point to see how good they actually are. Technically, we have already seen what Oppo can do at reasonable price point when the HA-2 came in for review. As a £260 product, it delivers huge spec, lovely build and appearance and tremendous sonic performance. All signs point to them being as capable of building great HiFi at sensible prices as well as premium ones.
The product you see here though is a real acid test of 'price refinement.' The Oppo PM-1 is defined more than anything else by the use of planar magnetic drivers - they even form the acronym for the title. Oppo did an amazing job of ensuring the PM-1 is a truly great headphone but you could argue that the £1,100 price tag of the PM-1 allowed Oppo to 'polish the cannonball' and design a product free of the limitations of real world product. The very fact that the PM-2 also exists which is a slimmed down PM-1 that uses slightly less elaborate materials and halves the price suggests this is the case. The PM-3 however, is intended to show that Oppo has sufficient grasp of headphone design to bring you a planar magnetic design at £350. Can they deliver on a tight budget and is the result any good?
DesignAs the name suggests, the PM-3 is the third and by far the most affordable Oppo headphone to use planar magnetic drivers. A full description of the technology is in the PM-1 review so I won't type it out again but the process effectively entails printing a voicecoil on a thin membrane rather than placing it behind a conventional dynamic driver. The result is a driver that is lighter and faster than a conventional one and additionally offers the scope for higher performance thanks to the characteristics of the driver eliminating some of the failings of a normal pistonic driver.
These advantages come with three drawbacks that can potentially trip up anyone looking to make a planar magnetic headphone at £350. The first is that the drivers are more expensive to make than a conventional type. This eats away at your available budget and reduces how much you have to spend in other areas. There are means of reducing this by efficient production and good use of materials though. Here Oppo has some clear form in the efficiency they've shown over the years making Blu-ray players and indeed in devices like the HA-2. They have the resources to be a big company so they can hopefully minimise the cost issue.
The other issues are rather more specific to what Oppo sees the PM-3 doing. The marketing, packaging and ethos of the PM-3 is aimed at the keenly contested hybrid market for headphones that are happy to work at home and on the move. This is logical in a commercial sense but raises some technical limitations of planar magnetic headphones.
The first is that they a generally less sensitive than conventional headphones and as a number of portable devices have fairly weedy amps on board, this could be an issue. Oppo has worked hard on the PM-3 to increase the sensitivity of the design so that the PM-3 is considerably more sensitive than its bigger brothers but still rather less sensitive than conventional rivals. This being said, with the HA-2 in the lineup, perhaps Oppo aren't as worried about this as they might be if they didn't also have an excellent portable headphone amp.
The other area where the PM-3 makes life slightly difficult for itself is that in order to be of any use on the move, it has to be a closed back design. This is something that runs counter to almost all planar designs - the larger PM-1 and PM-2 are entirely open backed and the closest price competitor to the PM-3, the Hifiman HE-400 is also built around these principles. Going to closed backs robs the planar design of some of the advantages it has in measurement terms but equally, it has to be this way if Oppo hope to sell any.
The overall styling and fit and finish of the PM-3 are all areas of good news though. The Oppo is handsome, well finished and extremely comfortable to wear. Oppo has managed to make the PM-3 feel like a close relative of the PM-1 despite the huge price disparity between the two and even with the expensive drivers in place, they have managed to make the PM-3 feel solid and well assembled. They've also managed to make it feel special while keeping the weight down to a manageable level.
The Oppo is handsome, well finished and extremely comfortable to wear.
How was the PM-3 tested?The PM-3 actually arrived at the same time as the HA-2 but whereas Oppo were content for me to crack on reviewing the HA-2 from the off, the PM-3 came with strict instructions to put 400 hours of running on them before I critically reviewed them. As such for 16 days, they were left chuntering away on the end of a Cambridge Audio DacMagic Plus taking a feed from my old R61 ThinkPad as the most energy efficient way I could think of to do this. I honestly don't know if Oppo makes this recommendation to dealers but it does seem a little enthusiastic for normal use.
For actual reviewing, the Oppo was tested with a Naim Supernait 2 integrated stereo amp and Yamaha RX-A3040 receiver with a variety of source equipment. It was additionally tested in a more mobile application with an iPad 3, Motorola Moto X and a Lenovo T530 ThinkPad, with and without the Oppo HA-2 and the Chord Hugo. Material used mainly consisted of lossless and high res FLAC as well as Tidal and Spotify and some on demand video material from iPlayer and Netflix.
Oppo PM-3 Sound Quality - MusicWith the required running in completed, the Oppo is a interesting headphone to listen to but this is largely 'good' interesting rather than a polite way of saying that it isn't very good. The most significant part of the PM-3's behaviour is that the required changes to the design do rob it of some of the true defining characteristics of a planar magnetic headphone but there is a huge amount to like.
Compared to the vastly more expensive PM-1 and the more price comparative Hifiman HE400, the PM-3 is more constrained and small scale because of the closed back design and the higher sensitivity of the Oppo's planar drivers. In addition their slightly smaller size means that the PM-3 also lacks the seismic low end that the larger models have. Once you have readjusted your perspective to these things though and judge the Oppo against rivals of similar size and design, the PM-3 really delivers.
The defining characteristics of the sound is that the PM-3 is extremely fast and can find immense amounts of detail in recordings. The low inertia of the drivers means that there is absolutely no overhang or sense of them changing direction and this makes them tremendously revealing and at the same time gives them a refinement that most rivals are going to struggle to match. Part of this stems from the ease with which the PM-3 reproduces high frequencies. Most headphones rely on a single driver to be fully range but the Oppo is an elegant demonstration that some drivers are more free range than others.
This means that when you play something with a bit of dynamic range and frequency response to it, the Oppo just lets the music happen in a way that is a little beyond even very well sorted conventional hybrid designs. It manages to sound unfailingly believable but rarely tips over into sounding ruthless or harsh even when the recording quality of the music in question isn't anything to get excited about. This also means that compressed material like Spotify stays entirely listenable as do internet radio and similar services.
There is also a slight sense of the same get up and go that I encountered with the HA-2 last month - by which I mean that it is present when listening to the PM-3 without the headphone amp present too. The PM-3 wants to find rhythms and keep your head nodding in a way that is subtly different to many Asian audio brands which prefer to concentrate on the soundstage and overall refinement. This is not to say that the Oppo isn't perfectly capable in this regard but it feels like the priorities of the brand are a little different to some rivals. Add the HA-2 into the chain and there is a real sense that the Oppo house sound is developing into something distinctive and exciting.
As to the possibility of adding an external headphone amp, the Oppo needs to be judged both by the standards of the design and the standards of its rivals. This is comfortably the most sensitive planar headphone I've ever seen and the first that can be legitimately run off a portable device with any degree of headroom. The acid test is whether the capable but limited output of the Motorola Moto X can drive a pair of headphones and in the case of the Oppo it can. Equally, judged by the standards of a normal dynamic driver headphone, the Oppo is still some way down the sensitivity charts. There is no question it responds positively to the HA-2 or Furutech ADL Cruise in a way that is far less pronounced with the Focal Spirit Classic. How much this matters to you is going to be down on your usage patterns and partnering equipment.
Oppo PM-3 Sound Quality - Film and TV?Unsurprisingly, given the Oppo puts in such a distinctive performance with music, none of these are significantly different when you watch film and TV. The detail retrieval that the PM-3 has is a real positive for low-level dialogue and incidental detail while the refinement levels work well when volume levels climb. While I feel that Oppo didn't consider this a huge priority when they designed their headphones, there is no issue with using the PM-3 in this fashion. Compared to true open backed home headphone designs, the Oppo can't recreate the scale of action soundtracks in the same way but it isn't adrift of key hybrid rivals.
The Oppo just lets the music happen in a way that is a little beyond even very well sorted conventional hybrid designs.
- Cohesive and clear performance
- Extremely well made
- Easy to drive for a planar magnetic
- Still less sensitive than a conventional headphone
- Earpads can't be changed
- Doesn't sound as open as some rivals
Oppo PM-3 Headphone ReviewThe PM-3 is in some ways the most interesting headphone to pass through the review process in some time. The result is a distinctive product that is in some ways different to any other design I've tested. The use of a closed back enclosure and the need for higher sensitivity means that they do not - for me at least - offer the full planar experience that the bigger models do. The seismic base and huge open soundstage have to give ground to physically make the PM-3 work in the context to which it has been designed.
Enough of what makes planar designs what they are is present in the Oppo to make it a seriously impressive performer. If you can live with the slightly limited sensitivity, this is a superbly built, exceptionally comfortable and immensely talented headphone that represents some of the very highest performance available at the price point. At this rate, Oppo Blu-ray players will be a sideshow to personal audio from the company and rivals should be genuinely worried.
Suggested retail price when reviewed: £350.00
Ease of Use8
Design and usability8
Value For Money9
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