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Discussion in 'Headphones (full-size)' started by justin_time, Jul 26, 2014.
  1. Justin_Time

    (I apologize. My previous attempt failed to download the pictures! See Updates at the end of the thread: significant sound improvement after 50 hours of break-in and replacement cable)

    [IMG width=500]http://www.head-fi.org/content/type/61/id/1163549/[/IMG]


    I am a big fan of Oppo. I have bought just about every product that this company had to offer for my Home Theatre for the past decade, from the Oppo 83 (updated to the 83-SE by Oppo for a song) to the Oppo 93 and 95, and more recently the Oppo 105. This amazing company always crams their products chockfull of advanced features while also pushing their design, build and performance right up against the point of diminishing return thus delivering to the consumers the best value for their money.

    Their latest offering, the Oppo PM-1 headphones, continues the company's tradition of excellence in design, build quality and value. But it is with genuine sadness that I must say that they did not meet the sonic performance that I expected from this great company. Mind you, the PM-1 is quite pleasant to listen to because of their neutral tonal balance. But the polite, inoffensive sound falls short on many counts: transparency, focus, details, soundstage and dynamics, especially in comparison to many excellent headphones today around the same price point, such as the Audeze LCD2 and the HiFiMAN HE-560.

    This brief review will focus on the performance of the PM-1. The HA-1 amp from Oppo was primarily used to drive the PM-1 but is not being reviewed here. Before I start, however, it is important to stress that I bought the PM-1 and (all the gears I discuss) for my personal use, so as a consumer I am often blunt sometimes about its performance. Good or bad, my comments are not meant as an endorsement or bashing of the product. I love and respect Oppo for the amazing things they have done in the area of Home Theater but this does not make me blind to the shortcomings of their newest product.

    [IMG width=500]http://www.head-fi.org/content/type/61/id/1163550/[/IMG]


    TONAL BALANCE: This is undoubtedly the best attribute of the PM-1. Its sound is smooth, well balanced and relaxing, calling little attention to specific areas of the music. I can enjoy these headphones all day with all kinds of music without fatigue or even the occasional annoyance of poor recordings. The PM-1 is very forgiving of the source. Switching to other headphones, however, I was immediately struck by the clear shortcomings of the Oppo PM-1: limited transparency, blurry details, constricted soundstage and limited dynamics. Sonically, the PM-1 is no slouch but it ultimately fails to clear the very high bar set in recent years by the very best headphones extant (Audeze LCD2/3, Fostex TH-900, Grado PS1000, HiFiMAN HE-500/HE-560/HE-6, Sennheiser HD800, and even the Ultrasone Edition 8). Given Oppo's stellar accomplishment with DVD/Blu-ray players in the past, I may have expected too much of this company in their first foray into the high-end world of headphones.

    MIDRANGE: The PM-1 possesses a smooth, neutral-sounding midrange. While highly listenable, this midrange lacks openness and transparency. It is also rather dull and missing the richness and sparkles usually associated with live music, which the best headphones come much closer to reproduce.

    BASS: While in good balance with the rest of the PM-1 sound, I find the bass short on tightness and weight; it provides insufficient foundation and impact to the overall sound. While this shortcoming may be overlooked with some Jazz or Chamber music, lovers of rock, symphonic and organ music will be left wanting more, much, much more.

    TREBLES: Even with the brightest-sounding amplifiers, the PM-1 trebles remain polite, almost subdued. While the sound is free of sibilance and stridency and is never unpleasant, I find myself yearning for more articulation and sparkles. The PM-1 shows shades of gray instead of a multi-colored palette.

    TRANSPARENCY: This is to me the greatest shortcoming of the PM-1. There is a veil over the entire audible range. But this veil is unlike the euphonic, caramel coating of the LCD2/3. The sound seems to simply lack clarity and openness.

    TRANSIENTS/INNER DETAILS: Unlike the best headphones, the PM-1’s transient attacks sound slow so percussion and plucking string instruments do not show their best here. Combined this with the limited transparency, and the PM-1 clearly lacks the crispness and details that give texture to music.

    FOCUS/IMAGING: The PM-1 has a natural center image that makes large orchestral music pleasant to listen to. The focus, however, is rather loose, again robbing voices and solo instruments of some of their immediacy or presence. The image in somewhat imprecise: various instruments are not clearly located within the soundstage.

    SOUNDSTAGE: Given the focus and imaging of the PM-1, I expected the soundstage to be large, only to be rather disappointed. The sound is confined to a very small space which is mostly two-dimensional. The relatively small size of the ear-cups, and for an orthodynamic design, the poor dampening of sound radiating away from the ears or perhaps the reflection of this out-of-phase sound back toward the ears may have contributed to this result.

    SPECULATIONS: After more than 30 years of using dipolar speakers (Accoustat 2+2; Accoustat 6; Martin-Logan CLS; Magneplanar 3.7), I have learned to recognize their susceptibility to the out-of-phase sound. As this sound radiates away from the listener, it can reflect against the back wall and come back to interfere with the direct, front radiating sound. This causes cancellation of certain frequencies, adding colorations to the sound of the speakers and destroying the soundstage. It is a lot more difficult and less successful to dampen this back-radiating sound—for speakers, it requires severe treatment of the back-wall—than to simply allow this out-of-phase sound to freely dissipate without obstruction by placing the speakers several feet away from the back wall. Back to the PM-1, when I covered the ear-cup grills, I could hardly detect any change in the sound which led me to believe that the out-of-phase sound is either being dampened against the back of the cups or allowed to reflect back toward the ears, or both. Many of the sonic woes of the PM-1 might be removed simply by using wide open grills with minimal restriction on the ear-cups. Or the dampening of the inside of the ear-cup (to prevent reflection of the out-of-phase sound) needs to be significantly reinforced.


    ERGONOMICS: Unless you're cursed (or blessed for better hearing?) with over-sized ears, the PM-1 ear-cups are adequately sized, larger than the Ultrasones', if not overly generous. The ear-pads are soft and the pressure against the sides of your head is just right to provide a good fit without excessive fatigue in long wearing. Unlike the HE-500/HE-6 headbands, the PM-1 headband is very well padded and adds a great deal to the wearing comfort. If you are used to the athletic size and weight of the HE-500/6 and LCD2/3, you would be pleasantly surprised here. The elegant ear-cups can also swivel and fold flat inside the travel pouch. Though among the lightest and smallest of the "high-end" headphones, I would not exactly call the PM-1 portable at nearly 400 grams without cable. The Ultrasone Edition 8 remains the sole king of the road.

    [IMG width=500]http://www.head-fi.org/content/type/61/id/1163551/[/IMG]

    DESIGN/BUILD/LOOK: The PM-1 looks gorgeous! It displays exceptional built and finish that rank way up there with the Ultrasone 8 and Sennheiser HD-800. The PM-1 makes the design and finish of the more expensive Audeze LCD3 seem amateurish. For example, there is no comparison between the elegant design and smooth functioning of the headband adjustment for the PM-1 compared to the klutzy design and poor finish for the same feature on the LCD3 at nearly twice the price (weird angle for the size adjustment, clunky slides and cheap, unfinished screws and lock-washers). While wearing the PM-1 may not be a fashion statement, try putting the HE-6, or worse, the LCD2/3 on your head and then look at yourself in the mirror.
    PACKAGIN/PRESENTATION: The Oppo PM-1 has the best packaging and accessories of any headphones I own, at any price, and that includes the, Audeze LCD3, Fostex TH-900, Grado PS1000, HiFiMAN HE-6, Sennheiser HD800, Stax 007, and Ultrasone Edition 8 & 10. My Oppo PM-1 arrived safely in a heavy-duty shipping box. Opening any Oppo product is a thrill. I found a pair of headphones tugged inside a sculptured foam padding within the sleek inner box, a protective cloth bag, a travel pouch, a gorgeous piano-finish wooden presentation box and a sleek headphone stand, all nestled within their own protective nest. All that for $1,200! Shame to the competition!

    [IMG width=500]http://www.head-fi.org/content/type/61/id/1163552/[/IMG]


    Owing to its rather reticent nature, the Oppo PM-1 delivers pleasant if un-exceptional sound with most amplifiers. While the PM-1 works well with Oppo's own HA-1, I achieve similar results with a variety of "bright" solid-state amps I own such as the Burson Soloist. The Schiit Mjolnir in particular gave the PM-1 the much needed sparkles—to use this amp, I re-cabled the PM-1 with OCC Silver wires and XLR connectors to improve transparency and soundstage. While the PM-1 sound improved, it never quite reached the highest level of performance exhibited by top competitors.

    As amplifier for the Oppo, however, I would stay away from the Bryston BHA-1, which made the PM-1 sound dull and lifeless. Also, with most SS amp, the sound remains generally veiled and two-dimensional. I got a more transparent midrange, better focus and generally richer sound from hybrid amps such as the Apex Peak/Volcano. Even small tube amps such as the MAD Ear+ HD, noticeably improved the PM-1 midrange, though the treble and inner details remain subdued. The bass was also much improved in volume if not in tightness.

    Hooking the PM-1 to the HeadAmp GS-X Mk2, Woo WA5LE and EAR HP-4 dramatically improved all aspects of the sound, suggesting that Oppo's own amp (the HA-1) and not the headphones was the weak link in the all-Oppo pairing. As much as the sound improved, however, pairing the $1,200 PM-1 with these expensive amps ($3,000-$5,000) makes no financial sense to me. It makes no sonic sense either as any of the top headphones (e.g. the Audeze LCD2/3, Beyerdynamics T1, Fostex TH-900, Grado PS1000, HiFiMAN HE-500/HE-560, Sennheiser HD800…) can outperform the PM-1 in most areas. The pairing of the PM-1 with these excellent amps clearly show, however, that the biggest weaknesses of the PM-1 are in the veiled midrange, slow transients and constricted soundstage resulting in the lack of dynamics and presence in the sound that gives life to music.

    NOTE: allowing the PM-1 to break in for about 48 hours improved the clarity of sound. However, the tonal balance and general characteristics of the PM-1 sound remain largely unchanged.


    As a long-time avid fan of Oppo, I was sadly disappointed by the sound of the Oppo PM-1 headphones. There is little doubt that the design, build quality and ergonomics of the PM-1 are first-rate and worthy of the high standard of excellence of this amazing company. Oppo paid attention to even minute details about packaging and accessories. Safely tugged inside the professional double box were a gorgeous presentation box, a traveling case and an excellent headphone stand. As usual with Oppo, you get a lot for your money.

    Unfortunately, given its price point, the PM-1 falls a little short in the most important department, the sound. While it is pleasant enough to let you enjoy most music, it lacks the transparency, articulation and dynamics that are expected from today's best headphones. Were the cost half of what it is, the Oppo PM-1 would compete favorably with all headphones from Audio-Technica, Sennheiser and Shure selling around $500-$600. Clearly, Oppo had a much higher aspiration. But against the big boys from Audeze, Fostex and HiFiMAN, Oppo first attempt cannot be called an unqualified success. The PM-1 remains, however, a good buy for those looking for a pair of attractive and comfortable headphones that produces a well-balanced and relaxing sound. This type of sound does not draw attention to itself but allows you to enjoy a variety of music at a leisurely pace. It is just not my cup of tea.

    On a positive note, the Oppo PM-1 has all the right ingredients to becoming a great headphone and is not that far away from it. I have a complete trust in Oppo. This company will swiftly react to the consumers’ feedback and rectify any shortcoming in the PM-1’s sound. I suspect the main problem resides with the handling of the out-of-phase sound. Whatever the solution maybe, I am confident that Oppo will find it and implement the necessary upgrade with minimal cost to the consumers. They have always done so in the past and will undoubtedly deliver again in the future. So look out competition!

    UPDATE 1 (8/3/2014)

    1. After 25 hours of break-in, the Oppo PM-1 opened up noticeably. The sound becomes more transparent and dynamic. Both the trebles and the sound-stage improve giving the sound more presence, air and a sense of 3-D space. Gone is the dull sound though overall the tonal balance is still somewhat polite.

    2. After 50 hours of break-in, the PM-1 definitely sound much more open and airy. It has acquired a more dynamic but not overly agresive sound. The tonal balance is now more neutral (read not dull anymore). I could not detect any significant change between 50 and 75 hours.

    3. I replaced the stock cable (I suspect copper wires) with the Silver Poison (OCC Stranded Silver with up to 1% Gold/Cryogenic treatment) from Toxic Cables. I could hear noticeable improvements all in the right direction. Now, the sound is more transparent with added presence and dynamics. The bass has very good impact. The tonal balance is more neutral: the mid-range remains smooth and effortless but there is significantly more inner details in the sound without objectionable brightness. The sound-stage has gained more depth so the sound is more three dimensional with a realistic presence.

    The break-in and Silver Poison cable have elevated the sound quality significantly from being dull and polite to open, dynamic and smoothly detailed without being bright or aggressive. I would now place the Oppo PM-1 near or on par with the HE-500 and LCD2 but still behind the HD800, HE-560, HE-6 and LCD3. I cannot wait to see what more time and the new (and free) replacement ear-pads would do. Thank you Oppo for quickly responding to customers' feedback


    UPDATE 2 (8/4/2014)

    1. The Oppo PM-1 has stabilized after 100 hours of break-in: there is not much difference between the sound at 50 and 100 hours. Replacing the stock cable with the Silver Poison (OCC stranded silver with up to 1% gold and cryogenic treatment) from Toxic Cables elevated the sound quality another notch, adding more openness, more details and slightly more bass. The tonal balance is neutral but still lacking air, presence and sparkles at the top .

    2. The Schiit Mjolnir is an excellent amp for the Oppo PM-1, opening the sound up a little further--I still would not call it transparent yet--and giving the mid-bass a little boost. It has less of the hard "transistor" sound of the Oppo's own amp/DAC, the HA-1. If you need an amp without a DAC for the Oppo PM-1, the Schiit Mjolnir is a very good choice.

    3. The new ear-pads from Oppo will arrive sometime this month.


    Amps tested with the PM-1:
    Apex Peak/Volcano
    Burson Audio HA-160D; Burson Soloist
    Bakoon HA-21
    Bryston BHA-1
    Cavalli Liquid Fire
    EAR HP-4
    HeadAmp GS-X Mk2
    MAD Ear+ HD
    Oppo HA-1
    Red Wine Audio Corvina/Bellina
    Schiit Mjolnir
    Vioelectric V181 and V200
    Woo WA5LE

    Cables: Silver Poison (Toxic Cables)

    Other Headphones Used in Comparison:
    Audeze LCD2 & LCD3
    Grado PS1000; GS1000
    Denon LA7000 (Lawton Modified)
    Fostex TH-900; Fostex LA-900 (Lawton Modified)
    HiFiMAN HE-500, HE-560 and HE-6
    Sennheiser HD-800
    Stax 007 Mark I
    Ultrasone Edition 8 Limited


    • Oppo 105 transport/DAC
    • PS Audio PerfectWave Mk2 transport and DAC
    Currawong likes this.
  2. Claritas
    Thorough and fair. Thumbs up on the thumbs down. :smile:
  3. TMRaven
    Good impressions.
  4. Justin_Time
    See new updates:  significant sound improvement after 50 hours of break-in and replacement cable

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