The LCD2 is the closest headphone that the PM-1 can compare to with regard to pure sonic clarity. To me, the PM-1 is a more comfortable side step or alternative for anyone interested in buying the Audeze LCD-2. There are a few differences of course. The Audeze has a more raw and pure bass, pristine in execution and lightning fast, where as the PM-1 has a slower and more loose but weighty texture. The Audeze midrange sounds a bit more distant and the treble is dry and less colored, the PM-1 midrange is more vibrant, thick sounding and intimate with more obviously colored treble response.
PM-1 Vs Audeze LCD-3
Audeze’s LCD-3 offers in my opinion the best tonality in any headphone ever made, with a perfect balance of purity and gentle warmth on the low end, very good depth of field and bass quality. The PM-1 suffered a defeat in the sonic clarity department compared to the LCD-3. Comfort and well roundedness are the only two areas the PM-1 headphones were able to defeat the LCD-3 in. Audeze’s background is less noticeable and more invisible, where the PM-1 background is noticeably jet black and omnipresent.
PM-1 Vs the Hifiman HE-500
If you liked the Hifiman HE-500 you really should be considering paying the extra cash for Oppo’s PM-1, as to me it is a more clear and similarly setup sounding headphone in terms of stereo imaging. The treble on the Hifiman has superior quantity and is much more noticeable. The PM-1 is much more relaxed with less quantity but retains a very slight but noticeable brightness to it. The HE-500 bass feels less firm and solid, as does the midrange.
PM-1 Vs the Sennheiser HD800
Surprisingly, on entry level summit level source and amplification, the PM-1 and the HD800 share similar midrange quality. Via my Red Wine AK120 and Burson Conductor SL, it becomes very hard for me to decide which one has the more clear midrange. Certainly, the HD800 smashes the Oppo in staging and treble potential, but it lacks that beautifully darkened background and rumbling low end the PM-1 has in abundance. Properly amped, the HD800 has some shockingly great treble that the PM-1 will never be able to obtain.
PM-1 Vs the AKG K812
The PM-1 simply is a better headphone in every way and for a lot cheaper. The only real quality the K812 has over the PM-1 is sound staging, which is exceptionally well formed with a good sense of width, something the PM-1 severely lacks. The treble on the K812 is just so awful sometimes that when I compare it side by side with the PM-1, I cannot help but feel incredible relief to not have to listen to that painful and icy upper end anymore. The PM-1 low end is more firm, more weighty and much more responsive. I feel the PM-1 midrange to sound more clear than the K812 in the rawest sense of the word. This is odd for me because I really like the K812 when it is properly EQ’ed but the K812 sounds so thin and lifeless compared to Oppo’s PM-1.
PM-1 Vs the Hifiman HE-6
Properly amped, the HE-6 is just one of the most tonally beautiful headphones on the market and I found it to outperformed the PM-1 significantly on treble and low end clarity. However, having a great treble response and a powerful low end made the midrange of the HE-6 sometimes a little forgotten. The PM-1 is noticeably more intimate and once again has a darker background, so everything seems to have a bit more pop. The PM-1 has a lusher thicker sound but the HE-6 has more weight on the low end with a purer and cleaner bass experience and a more sparkled treble response that leaves the PM-1 a little dusted and confused. (Don’t feel bad Oppo, the HE-6 bests pretty much everything in existence on the treble in my experience, even a few of the expensive Stax models.)
The biggest concern I had during testing are the recessed mono 2.5mm ports on the bottom of each earcup, which make it darn near impossible to create custom cables. I had Artemis cables replace the stock adapter terminations with some balanced 4-pins for my balanced rig. They do beautiful work, but those ports should be dead flat with the earcups so cable makers don’t have a heart attack trying to find 2.5mm mono adapter housings that are super skinny just to fit the PM-1 housing. Sonically I would prefer a bit more treble presence along with a cleaner, more pure bass texture. I feel the bass on the PM-1 to be a bit loose sounding and really hoped it would set itself apart in some special way from the Hifiman or the Audeze headphones. If Audeze can achieve such purity in the bass on the older LCD-2 Rev2, I think Oppo is more than capable of squeezing out more purity and cleanliness in the texturing of their low end.