Planar Magnetic Driver

OPPO’s headphones use driver technology that is a bit unique, at least compared to more conventional headphones.

OPPO explains:

Sound is generated by a very thin and light diaphragm whose entire surface area is evenly driven. The diaphragm is driven in a symmetrical pull-push manner and the magnetic system and conductor patterns have been optimized for maximum sensitivity and consistency. This allows the diaphragm to generate very stable and linear piston-like vibrations, ensuring phase coherence and high resolution performance with minimal distortion.

The diaphragm is incredibly complex with seven individual layers! It utilises a spiralling pattern of aluminium conductors on either side of the diaphragm surface. Naturally, with twice the number of conductors within the magnetic field, it fully utilises the available diaphragm/conductor area resulting in greater efficiency and control. Even the magnet system utilised has been the result of careful computer design with very high energy Neodymium magnets. This Planar Magnetic driver sets it apart from the majority of headphones on the market. The driver has a purely resistive impedance, which means that it’s easier for the amplifier to drive it and that sound quality is unaffected by a headphone amplifier’s output impedance.

The OPPO PM-1 and PM-2 have a circumaural, open-back design, whereas, the PM-3 has a closed back. All use the Planar Magnetic driver.

Design

To casually look at the PM-1 and PM-2 you would think that they are the same pair of headphones. Only minor detail changes and better cushioning materials differentiate them. The PM-3 is a little smaller overall, with a different finish for the closed back design. I have to say that I really love the look and feel of all three OPPO headphones. They impart an impression of being luxury goods, being all black with silver highlights. (The PM-3 is also available in white) They stand out with a clean modern look; almost minimalist in design with very good attention to detail.

The headband is thickly padded and the interchangeable ear cushions are delightfully soft and comfortable. In fact, these headphones feel great to wear for hours at a time, with just the right amount of clamping pressure to keep them on your head, without giving you a headache or the feeling of fatigue. It has a cossetting effect on the head and makes you feel immediately comfortable without being constrained or overly snug or tight. Moving your head up or down or left to right quickly, is accomplished without feeling that they will shake off or dislodge easily. They are also remarkably easy to put on and take off, due to the ear cushion size, shape and the overall design.

PM-2 weighs only 385 grams without cable (the cables are detachable), whilst the PM-3 is even lighter, at 320 grams. A lack of weight is something that every headphone user rejoices over and in conjunction with all the comfort features of the OPPO’s, makes for a very enjoyable experience, even before you have heard a sound from them.

Something that I think is easily overlooked is the connecting cable, but it plays an essential part in the sound quality and comfort to a user of course. In the PM-1 and PM-2, the connecting cable is covered in a finely textured cloth material that feels pleasurable to use and never gets snagged or tangled. It is also light and doesn’t feel like it tugs on your person, as you move around.

Although quite firm pressure is needed to adjust the headband size, it feels in tune with the overall quality feel of the units, as nothing is loose or fits poorly. Happily, the band adjustment doesn’t alter over time. The overall fit and finish is absolutely faultless and they feel like they are built to last for years to come. They are in keeping with the asking price and are as good, if not better than their rival products, some of which command much steeper prices.

Auxiliary Equipment

For the listening exercises I used a number of high quality headphone amplifiers. I think that anyone that is serious about really hearing what the OPPO headphones are capable of, has to use the best auxiliary components that you can afford. I chose units that are keeping in line with the price point for the headphones. All add their unique contribution to the sound. I used OPPO’s own headphone amplifier, the HA-1 ($1790), the Benchmark DAC 2 HGC ($2840) and the Burson Audio Conductor SL ($1375).  Also at hand to compare against the OPPO trio were the popular Audeze LCD-2 headphones ($1640) and the Sennheiser HD 800 headphones ($1699).

Listening

Starting off by using the OPPO mid-ranged PM-2, I was immediately impressed with a lovely well balanced sound, one that makes extended listening very entertaining. It was never dull or flat but instead lush, warm, full and really smooth. It was also dynamic and alive sounding with good tempo, drive and great bass extension. In fact that is pretty much how all three OPPO headphones sound. The benefit of the planar magnetic design, as applied to all three models is of smooth coherent sound, without any apparent vices. You readily hear lots of fine detail that you could easily miss on a regular speaker system.

Listening to Dire Straits well known “Brothers In Arms” album, on the title track, you hear the detail of the synthesiser in the background and the effects that provide the eerie atmosphere sounds, all which are clearly heard. It was so clear that I could follow the synthesisers and the tones being generated, rather than the lead guitar that I normally focus on. Each has its own space and air.

In “So Far Away From Me” the texture of the instruments is evident. The snare drum hits are tight with an echo that reflects within the room and the kick drum sound is rounded, like the surfaces are well damped or wrapped in a layer of cotton wool. The female backup singers performing the harmonies for the first 25 seconds of the track are clearly audible, and then male vocals interchanging later on in the track.

Swapping to the PM-1 gave me a slightly quieter background; blacker and allowing for finer, faint detail to emerge. It punches harder also. With the “Money For Nothing” crescendo 1:30 minutes into the track, the PM-1 doesn’t compress the track as much as the PM-2. You know the part that everyone turns up to either show off their systems to their mates, or even just to themselves? It plays harder, stronger, and longer without dynamic compression or the feeling that it’s reaching its output limit. You pay more you get more.

What about paying less? The OPPO PM-3 is somewhat different to the PM-2, PM-1 twins. Although having the same styling and quality fit and finish as its more expensive brethren, the fit over my head wasn’t as comfortable, particularly as it is a little smaller and didn’t cover over my ears completely. The planar magnetic driver is a round 55mm in diameter, rather than the oval 85 x 69mm drivers found in the more expensive models. An oval shape ear piece is preferable for my ears.

The PM-3 is a closed back design, which is very useful in a noisy environment, or when you want to listen in private. It too has a strong sonic family resemblance and is a smooth performer. It definitely has the same type of class as the PM-1 & PM-2, but doesn’t have the same amount of class. There is the sense that there is a little less of everything audiophile, soundstage air, space, midrange definition and detail. What is not remiss is the dynamics, punch, color and sense of fun, as the PM-3 really gets down and boogies very impressively. They have an intoxicating sense of enthusiasm, with a good punchy bottom end and depending on the music you prefer, may make this your headphone of choice.

Listening to Cecile McLorin Salvant’s ‘WomanChild’ album opening track “St. Louis Gal” you simply have a guitar accompanied by just her voice in a nice, open recording, so there is nowhere for it to hide if it doesn’t sound right. The PM-3 sailed through the track, sounding natural and alive, with her voice sounding nicely uncompressed, but the guitar just a little boxy particularly in the lower notes and reverberation.

The next track “I Didn’t Know What Time It Was” just gets my foot tapping every time. The first thing you notice about this track is the brushwork on the snare drum. With the PM-3 it’s easy to follow; the soft texture was distinct sitting below the stronger piano and bass notes. The piano sounds great, each note being distinct from each other and stopping appropriately without running into the next one. It has a nice sense of timing. Her voice sounds clean and full of her distinctive character.

Switching to the PM-2, the soundstage grew larger and fuller, both wider and taller. The bass was better defined, less boxy, allowed the double bass tempo to set a reliable pace with a clean frequency response that was better balanced top to bottom, with additional detail and realism. Notes started and stopped faster.

The same track played through the PM-1 gave it an even larger sense of space that the music plays within, with a greater sense of ease and musicality. The bottom octaves have a greater sense of body and control, with more meat on the bones. It is not substantially more, but, a few degrees more of everything that makes music enjoyable. It certainly has a close family resemblance to the other models. The PM-1 simply does the same thing with more control and less effort, sounding like a bigger speaker. There is less fatigue and stress.

Headphone Comparisons                                                          

I was fortunate enough to have had at hand a couple of comparative headphones that help put the character of the OPPO headphones into perspective. I tried the Sennheiser HD 800 and was sadly disappointed. Again with the same Cecile McLorin Salvant tracks, the Sennheiser sounded slow and dreary by comparison. It had nowhere near the same dynamics as any of the OPPO’s. It was nice and smooth but it suffers a noticeably recessed midrange and bass, that doesn’t excite or recreate life in the music. I found myself wanting to turn the volume up to get some impact and punch but even then it didn’t deliver. It was also the most inefficient of all the headphones that I tried and required at least double the volume setting to match the output levels. A generation away from the OPPO’s refinement and overall musicality.

And please don’t get me wrong on this subject of excitement due to the perceived need for an overly generous volume setting. The OPPO’s are thoroughly rewarding at even very low levels of volume, as they are so natural and full sounding, scaling appropriately with the volume setting, you don’t need to crank them up to get life, punch and impact. 

The Audeze LCD-2 headphones impart a softer musical rendition, with a slower overall pace that’s relaxed in its feel. It’s a real smoothie! It’s very open sounding and has a gloriously detailed top end. There is slight dynamic compression and a little softening on the bass/kick fullness, especially compared to the dynamic OPPO’s. There seems to be less midrange energy and it gives the impression that it’s not as full sounding, but it’s the type of headphone that you need to spend some time with to appreciate it properly, the detail and definition is certainly there. In fact, it allows for greater definition on certain types of music as you peer into the sound, rather than be presented with the sound. They don’t punch as hard as the OPPO’s, which is the better pairing for rock music with its punchier bass and forward sound. Overall, the LCD-2 has a less forward presentation while exhibiting well controlled sound, without the feeling that any one area dominates.

Headphone Amplifiers

Finally, just a few words on the value of matching headphones with an appropriate amplifier. Personal choice will naturally play a great part here. I selected three combination DAC/Headphone amplifiers, that are truly excellent, but they each have their differences. For instance the Burson Audio Conductor SL with the optional Burr Brown PCM1793 DAC on-board, has an overall nice smooth sound with plenty of punchy dynamics. It’s full range, neutral, with an open soundstage and with plenty of detail retrieval. This makes it a very well-rounded unit and great value when teamed with the OPPO’s.

The OPPO HA-1 headphone amplifier also is smooth and detailed, but has the added benefit of having the fastest and most dynamic sound, but without quite as much extension at either end of the spectrum.  It works very well with all the OPPO models, adding to their strengths, but it also makes the Audeze headphones better by giving it additional speed and punch. The HA-1 was by far the nicest of the three to use, with its large color front screen and overall flexibility; it was a delight and made me feel special every time that I used it.

The Benchmark DAC 2 HGC is even more refined with less user fatigue and the least amount of confusion in the midrange. Using the Benchmark gave additional detail to all musical sources and it’s also cleaner and the smoothest here. As the most expensive of the three, one would reasonably expect a little more performance for the money and it doesn’t disappoint. It will happily deliver, over your expectations, with any headphone pairing.

As the OPPO headphones firstly have great input sensitivity and are a purely resistive load to the connecting amplifier, they will successfully pair up with almost any device. They work very well connected to an iPad, or a smartphone, but naturally will improve drastically with higher quality playback equipment. Do yourself a favour and hear what they are truly capable of. Incidentally, they all improved by using a well-designed shielded power cable and a quality USB cable connected to the amplifiers.

Conclusion

I have always had respect for the way that OPPO manages to produce distinctive high quality products with intelligent design, in an overcrowded market. That has been true of every piece of equipment that I’ve sampled from them. The Planar Magnetic headphones are no exception. They shake up the established name brand headphones, with cutting edge technology and new levels of audiophile performance. They really are a masterpiece of design. They look timeless and elegant, are built to an incredibly high standard, are exceptionally comfortable and deliver unmatched sound quality. This combination, in my opinion, is simply unbeatable.

If you can afford the PM-1, just buy it. You will be purchasing the best sounding headphones that I’ve ever heard for the money. I think that you will agree.

The PM-2 comes in very close to the PM-1. As a value proposition, it is exceedingly good. It delivers 90% of the PM-1’s performance, but for $600 less. I would happily put that money towards a really decent headphone amplifier and cabling.

Or you could purchase a PM-3 for the daily commute and keep the change. This hand grenade of a headphone is a no brainer. I loved its addictive big dynamic sound. Snare hits, bass guitar and kick drum are all the more real and interesting when played through the PM-3. And for only half as much as its bigger brothers, it has to be a bargain. I can heartily recommend any of these quality headphones to you.

OPPO is distributed in Australia by Interdyn.