Back in 2014 Kyle reviewed the Oppo PM-2 (https://headfonics.com/2014/11/the-pm-2-planer-headphone-by-oppo/) and concluded that the PM2 were an amazing set of headphones with only but a few flaws.
Kyle was not the only person to notice their potential. Luckily for us, one of the fans goes by the name of Alex Zaets; a dedicated audiophile with profound knowledge of audio design. He went through the trouble to modify the headphones’ base design and commercialized his modifications under the brand name Audio Zenith (maintaining his private name’s initials A.Z.).
His modification goes much deeper than adding or changing some dampeners and replacing the ear pads. His aim was to greatly enhance Oppo’s core design, precisely doubling it, for which he came up with the name „PM times two“ or in short, simply PMx2.
The Audio Zenith PMx2 can be purchased for 1.899 $ or optionally you can have your PM2 transformed irreversibly into the PMx2 for 899 $.
For your information concerning the following review: I am familiar with the original Oppo PM-2. However, I do not have them myself and I was not able to get my hands on them for a detailed comparison. My trusted headphone dealer informed me that the PM2 are not in production anymore. As of now, Oppo Digital has removed the PM-2 from their official website altogether. This could also be a threat to the PMx2 in the future, which heavily rely on the stock PM2.
A New Update
The PMx2 did not just recently surface. In fact, Audio Zenith has been popular in the scene for a while and garnered a lot of positive feedback for said modification. However, the unit of this review is a further update of said improvements.
The version history can be easily identified by the color of the ear cups’ grills which are colored silver since April 2017. Alex does not refer to the update as V2 or Mark II. Instead, he calls the current PMx2 “the final revision.” So if you are browsing second hand markets, be sure to look out for the silver cups opposed to Oppo’s original black ones.
Unfortunately, the further modifications are not of the simple kind. Also, dealers have raised interest and thus the price had to be adjusted by 500 $. The original PMx2 went for 1399 $ opposed to the updated 1899 $. For that, you are promised lower distortion along with higher resolution and a bigger soundstage.
New Ear Pads
A lot of the sound improvements come from the replaced ear pads. The original PMx2 had black velour pads that have now been replaced by lamb’s leather. They do share a similarity as in that their foam is separated into different zones with varying stiffness.
This is an incredible feature that many headphone manufacturers overlook altogether. I have to admit that I have a difficult time telling the different levels of stiffness apart, even when squeezing the pads with my fingers, but there is no mistaking the pads change the sound for the better. They feel comfortable and solid at the same time – if that makes any sense.
The pads themselves feel squishy and soft – perhaps not to the level of the most softest memory foam – but as soon as you put the headphones on, you have the impression as if your ears were in an enclosed room. Now this is a convenient description because Audio Zenith actually wants to have you think of a room in regards to the ear pads. In one of the videos on their homepage Alex describes the sound in a triangle system and how the listener, speaker and room translate to the ear, transducer and ear pads, respectively. I definitely recommend to check out the videos if you have the time.
Of course the modifications don’t stop there. The whole headphones are disassembled and there is a lot of tinkering involved. Audio Zenith were kind of enough to share details in a private conversation, but I was also asked not to share it. The process does sound almost painfully cumbersome. It made me realize how convinced Audio Zenith are that the modification is worthy of all the troubles.
Audio Zenith attached a “patent pending“ sticker on the inside of one of the hinges. I could not figure out what this actually refers to. I do think it is a bold move to take the product of another company, to tinker with it and then trying to put your own patent on it. I’d prefer if the sticker were not there.
Packaging & Accessories
The review unit was sent across the sea and arrived safely in Europe. The outer boxing is by Oppo but rebranded to Audio Zenith with a sticker. It is definitely one of the lighter packaging you will find among high-end headphones. One could up the experience of unboxing with some more layers and fancy documentation. This would also distance the PMx2 better from the Oppo PM-2.
As is the packaging, the accessories are also taken over from Oppo. The headphones come with two cables and a surprisingly portable carrying case. The case is only slightly larger than that of the portable PM-3 headphones and it features a similar jeans texture design and black zippers. The cover is a bit softer, though, and I don’t recommend to accidentally sit on it. It does make a great travel case, though. The centered Oppo logo has been covered by yet another Audio Zenith sticker. Due to the texture on the case, I think this sticker lacks grip and will be the first (or only one) that will come off eventually.
Build Quality, Design & Comfort
The PM Legacy
Oppo Digital completely won me over with the beautiful PM-3 portable headphones. The design is very similar to the PM-2 and PM-1 with the lower numbers having an even better premium feel. I think there is hardly any headphone design out there that is significantly better than that of the Oppos – at least not in a traditional design that does not exceed usual size and weight.
Audio Zenith definitely chose the right model as a base here. The metal finish is outstanding and the headband is as simple as it is genius. The rasterization is rock solid. Weight comes in at just below 400g and they are distributed well over the head. Clamping force is more reminiscent of a portable design, perhaps, but it feels very good on my head nonetheless.
Next to the replacement pads, there are a few different design cues, too. Audio Zenith covered up all original branding and used stickers to replace them with their own. Now that doesn’t sound too fancy and I have to agree that the original Oppo print looked better.
Yet the stickers match the overall design well. They are mostly black and silver but the silver reflects in rainbow colors. It is not flashy but definitely noticeable. Audio Zenith told me that they actually do have an agreement with Oppo that allows them to cover up all of the original branding, which is nice from A.Z. to ask for in advance.
Silver Metal Trim
Interestingly, the headphones have a slim silver metal ring just next to the ear pads. This slim metal ring also reflects in the same colors. Now this left me quite puzzled because the metal ring is from the original Oppo design. No other stock part reflects in the same colorful way. If Audio Zenith actually went through the trouble to replace it for a better match, I take my hat off!
I do think the stickers could be printed in a higher resolution and I am slightly annoyed that the silver borders are asymmetrical. This is something to only bother the very attentive, like me for example.
Although it says Audio Zenith on the hinges, the actual AZ logo won’t show unless you expand the headband. I think that’s a cute detail. At first, the logo reminded me of some star-shaped symbols of which various pop into mind. It is, however, an overlay of the letters A and Z that have been adjusted for symmetry in a surround-sound speaker setup.
Ear Pads & Isolation
I already mentioned the ear pads before and how vital they are for this modification. They’re made from genuine lambskin leather. The pads are not angled opposed to the previous PMx2 design with velours pads. Also the zones have been rearranged accordingly.
On the inside of the right side it looks like the leather had to be re-stitched but this could very well be an exception of the review unit. Even though the pads enclose the ears nicely, do not expect any isolation from any open-back headphones, for that matter.
The PM2’s design features removable cables via 2.5mm connections on both sides. The PMx2 come with the same two cables as the Oppo. The main cable is of very high quality, 3m in length and covered with cloth beneath the y-split.
It is thick and feels durable, yet doesn’t come off as too heavy. It terminates in a 6.35mm jack. The Oppo logo has once again been covered by a Audio Zenith sticker that actually doesn’t feel out of place at all. It fits perfectly in size and matches the dual line design of the Oppo in color and size.
The second cable is 103 cm short and feels awfully flimsy. It is very thin and has an annoyingly strong memory that keeps pulling itself back into the packaged circular shape. It has no branding at all. It is a welcomed temporary solution if your source only has a 3.5mm input but eventually you will want to replace it.
The Oppo design does naturally support balanced cables. I think it would have been a nice touch if Audio Zenith could have replaced the short cable with a balanced cable instead.
Page 2: Sound Impressions