Jumping off the deep end… cliché as that sounds, there’s no other way to describe OPPO’s entry into the headphone market with the $1099 planar magnetic PM-1. Based in California’s Silicon Valley, OPPO Digital (hereafter referred to as just OPPO) is independent of China-based OPPO Electronics in everything but name. OPPO develops products for A/V enthusiasts – mostly high-end disc players. Perhaps, then, it’s not so shocking that the company’s first headphone product is designed – and priced – for the serious enthusiast.
Form & Function
The PM-1 begins its assault on sensibility before the box is even opened – the package is surprisingly hefty, and pulling out the double-boxed headphones is an experience in itself. I’ve come across very nice headphone packaging in the past – Audeze, Sony, and Beyerdynamic, among others, all pay very close attention to the presentation of their high-end products. OPPO simply outdid them with the PM-1.
The polished, suede-lined wooden box with its push-button lock is nothing short of gorgeous. The headphones also come with two sets of pads, lambskin and velour, as well as two cables – a 3m (9.8’) OCC cable with a 6.3mm termination and a thin 1m (3.3’) OFC cable with a 3.5mm plug. The latter could be a couple of inches longer for my liking. The cables are dual-sided, and attached to the PM-1 via a pair of recessed 2.5mm connectors, not a mini-XLR as with Audeze products or proprietary coaxial connectors used by HiFiMan. A balanced cable for the PM-1 is available as an optional accessory.
The pads, like the cables, are extremely easy to swap, though I ended up preferring the stock lambskin pair. The velour pads are very nice in terms of feel and “breathe” better than the lambskin pads, but they also bottom out a little easier on my ears. With the velour pads the tips of my ears touch the grilles slightly, creating pressure points after prolonged listening.
A compact denim carrying case into which the headphones fold flat is also included. This, combined with the short 3.5mm cable, grants the PM-1 some degree of portability. The PM-1 is also driven more easily by portable players than the Audeze LCD-2, HiFiMan HE-560, and Sennheiser HD600, but don’t expect to use them on the go. Thanks to greater damping, the PM-1 doesn’t leak as much sound as an LCD-2 or HE-560, nor does it look as ridiculous on the head, but it is still a full-size, open-back can. That said, I was able to conveniently transport the PM-1 to work and back and easily use it around the house with the HiFiMan HM-901 in my pocket, which is more than I can say for my other top-tier headphones.
The design of the headphone is just as impressive as the unboxing experience and pack-ins – simply put, the PM-1 is a luxury headphone that makes compromises in neither look nor feel. The metal structure of the PM-1 has a degree of ruggedness that my wooden headphones simply lack and its design is handsomely understated. The construction quality and choice of materials are top-notch – what the eye sees and the hand touches is all either metal or leather. The last headphone that impressed me anywhere near as much in this regard was the Bowers & Wilkins P5.
Planar Magnetic headphones don’t have a reputation for light weight, and the PM-1’s all-metal frame is hefty, but not heavy. It’s noticeably lighter than the LCD-2, for example. The earcups can pivot independently about two axes and the padding is ample, so while it is not quite as light on the head as the dynamic-driver Sennheiser HD600, the PM-1 remains comfortable for many hours at a time.
Now, on to the sound.
[su_spoiler title=”Test Gear List (click to expand)” anchor=”#gear”]
- Tianyun Zero DAC/amp (2008 version)
- Heed CanAmp
- Anedio D1
- OPPO HA-1
- HiFiMan HM-901 (with Minibox amp card)
Headphones used for comparisons
- Audeze LCD-2 (original model)
- Sennheiser HD580 w/HD600 grilles, headband, and pads, and HD650 cable. This HD580 uses the “new” driver revision and to the best of my hearing ability is identical in sound to a current HD600. I will refer to it as “HD600” throughout.
- HiFiMan HE-560
[/su_spoiler][su_spoiler title=”Manufacturer Specifications (click to expand)” anchor=”#specs”]
|Acoustic Principle||Open back|
|Nominal Impedance||32 Ohm|
|Sensitivity||102 dB in 1 mW|
|Clamping Pressure||5 N|
|Weight||395 g (without cable)|
|Driver Type||Planar Magnetic|
|Driver Size (Oval)||85 x 69 mm|
|Magnet System||Symmetric push-pull neodymium|
|Frequency Response In Free-Field||10 – 50,000 Hz|
|Long-Term Max Input Power||500 mW according to IEC 60268-7|
|Pulse Max Input Power||2 W|
In contrast to the dynamic (moving coil) transducers used by the vast majority of headphones currently on the market, the PM-1 utilizes planar magnetic technology. Lots has been written on the subject of planar magnetic drivers by those far more qualified, so I will only concern myself with the resulting sound. Anyone interested to learn about the tech in more detail can read about the way PM drivers differ from other transducer types in the Wisdom Audio white paper here. Though written with speakers in mind, the underlying technology is the same. Tyll’s headphone-specific article over at InnerFidelity is also a great read.
In brief, the OPPO PM-1 to me sounds balanced, smooth, and natural. It has good note thickness across the range and nothing in the sound signature juts out. It is not bassy, though the mid-bass region has very good punch, and not at all fatiguing.
There is a bit less subbass than I’d gotten used to with the LCD-2, but being accustomed to the Audeze sound has a lot to do with this. I’ve always considered the LCD-2 a little bass-heavy, and its subbass extension is admittedly superb. The PM-1 is not a bass-heavy headphone, but it is capable of belting out the low notes with authority when necessary.
Overall, the sound seems a little biased towards the midrange and a bit shy in the treble region. The mids are full-bodied and very smooth – a theme that the PM-1 follows throughout – but the upper midrange and treble have a little less presence than I would consider “flat”. While the PM-1 doesn’t sound dull per se, it lacks the crispness and overall refinement of some flatter-sounding sets as a result. It is extremely non-fatiguing and forgiving, however, which has been a blessing every time I’ve ended up using it the whole day straight.
The PM-1’s mild treble dip has an effect on the presentation. The headphone doesn’t have the largest soundstage and sometimes seems to have more in common with higher-end sealed-back headphones – it is less open-sounding and airy compared to a few of the other open-back cans I’ve tried. I’ve never been too thrilled with the LCD-2 in this respect either, but the Audeze does image a touch better. A little more treble presence would have done the PM-1 good in this regard.
One area in which the PM-1 excels is drivability – it maintains its performance incredibly well with lower-end. It is driven more easily by portable players than my other full-size headphones, especially by the HiFiMan HM-901, which is able to power the PM-1 with ease.
That about sums up the PM-1 for me – a smooth, easy-going headphone with impactful bass and slightly mid-centric sound, driven well by all kinds of sources. What follows are more in-depth comparisons to two other planar magnetic cans, the Audeze LCD-2 and HiFiMan HE-560, as well as to the dynamic-driver Sennheiser HD580/600.
Audeze can be credited – at least in part – with launching the Planar Magnetic trend among high-end headphones in recent years. Planar Magnetic technology has been around for decades, of course, but the LCD-2 is the headphone that introduced it to my generation of headphone enthusiasts on a wide scale, starting about four years back.
Compared to the aging LCD-2, I find the sound of the PM-1 more balanced and a little more neutral. I like its lack of bass emphasis, which suits me better than the weightier low end of the Audeze. The LCD-2 has better sub-bass rumble, but I’m happy to give that up for what I consider to be more natural bass quantity. That’s not to say that the PM-1 is bass-light – its sound is very dynamic, and the bass presents with good punch when necessary.
The PM-1 is a bit clearer and more neutral, thanks in part to its more mid-centric balance and its slightly more natural treble energy. The Audeze has a warmer tonal character, thanks to the combination of heavier bass and similar, if not lesser, sum treble energy. Generally speaking, the PM-1 and LCD-2 seem to have a similarly non-fatiguing treble character compared, for example, to the HiFiMan HE-560 or a “reference” in-ear monitor such as the JHAudio JH13 Pro. Still, the PM-1 has a slight tendency to make the LCD-2 sound a bit dull and smoothed-over in comparison.
The presentation of the LCD-2 is a touch more open, with marginally better imaging ability. However, when the LCD-2 has occasion to show off its low end prowess, its advantage on the imaging front can become lost to the bass.
The PM-1 is easier to drive than the LCD-2. It is also much more compact and less ridiculous-looking – if I wanted a full-size headphone to use as part of a transportable rig, the PM-1 would be it by a margin. Comfort is a wash, as the LCD-2 has more room inside the earcups but suffers from greater weight and padding that just isn’t quite as supple and luxurious as that of the PM-1.
The Sennheiser HD580/HD600 is one of my all-time favorite headphones, a balanced and open affair with a tonal character pretty close to neutral. I personally prefer the sound of the HD600 to that of the Audeze LCD-2. Next to the HD600, the PM-1 sounds darker and more focused on the midrange. Its bass is more impactful, with both mid-bass punch and sub-bass rumble exceeding those of the Sennheisers.
The PM-1 is warmer and more full-bodied than the HD600, which offers up more treble energy for a brighter tone. While arguably more neutral, the HD600 also sounds a little thin in comparison. This thicker note character of the OPPO unit, combined with the smoother, somewhat laid-back upper midrange and treble, makes the PM-1 appear to be lacking slightly in definition compared to the Sennheiser.
The PM-1 is significantly more efficient than the HD600 and leaks less sound into the environment. The HD600, however, has more spacious earpads and benefits from the lower weight of its dynamic drivers compared to Planar Magnetic transducers – it is significantly lighter than the PM-1, HE-560, and LCD-2.
The sound of HiFiMan’s new HE-560 has less in common with the PM-1 than do the LCD-2 and even HD600. A follow-up to the HE-500 model, its tuning is somewhat like applying a v-shaped EQ filter to the PM-1, lifting up the lows and highs.
The HE-560 is bassier than the PM-1, and the extra bass gives it a slightly warmer tone. At the same time, its treble is more energetic and extended, allowing its presentation a more “open” feel. The extra treble energy sounds more natural to me, but the HE-560 also appears less full-bodied (i.e. “thinner”) through the midrange. This grants it a more “analytical” note presentation that some listeners may not find appealing. Overall, however, the upper midrange and treble of the HE-560 are more well-defined, more crisp and nuanced.
The mid-centric PM-1, on the other hand, sounds extremely coherent with its stronger, thicker midrange. Its bass is just a hair more boomy and it has smoother, completely fatigue-free treble that can make it sound a little vague and lacking in crispness next to the HE-560 – smoothed-over is the best term. The PM-1 also doesn’t quite have the same open, well-imaged presentation, but is more efficient and would again be my pick over the HE-560 for a transportable rig.
The OPPO PM-1 is a full-size, open-back planar magnetic headphone with fantastic craftsmanship and a top-tier price tag. It is superbly comfortable in both fit and sound – something I can really listen to for many hours straight. The design is more restrained compared to most other top-tier headphones, and the simple-to-swap parts, low amplification requirements, and easy-going sound all indicate that the PM-1 was developed just as much for the high-end consumer market as for the audiophile one.
Another piece of good news – the PM-2 model will be along shortly, utilizing the same sound reproduction technology and priced at a more reasonable $699 to nudge up the value for the more audio-minded.