Oppo PM-2 - Any Good?

Ha totally fair, I'm as susceptible to FOTM hype as anyone. I will say the PM-2s aren't that new to me, just the addition of the velour pads, so I think I'm mostly over my general "new toy" phase with them. Partial list of headphones I've owned:

HD 580/600/650
Fostex TH-X00 (Mahogany)
Shure 1840/1540
Stax SR-L500
DCA Aeon RT Open
Denon D2000
Grado S80(i? e?), GW100
Final Sonorous IV
Philips Fidelio X1/X2
Beyer DT 150/770/990/177x/TYGR 300R
Audeze Sine/iSine 10/LCD-1/LCD-2C
NAD Viso HP50/HP70
Audioquest Nighthawk/Nightowl
Hifiman 400s/4xx//Edition S/Sundara
Avantone Pro Planar
PSB M4U1/M4U8
1More Triple-Driver
Modhouse Argon Mk3
OPPO PM-3

I'm definitely forgetting some and most weren't directly compared to the PM-2, just from memory, so that's admittedly not ideal.

I've also auditioned a good number of other headphones, including a couple Focal and ZMF headphones, but I don't know that I spent enough time to claim a well-informed comparison.

For what's worth I have the PM-2s and the PM-3s right now, owned the PM-3s longer actually, and while I find the PM-3 very good for portable closed headphones, they very much sound like portable closed headphones in terms of being narrow and a bit claustrophobic in their presentation. Also a bit rolled-off in the treble and not super dynamic. Very good for what they are, but I would consider the PM-2s clearly superior.

 

If it makes any difference @Philimon, I had a loaner PMx2 with the sheepskin pads and the PMx2's I purchased with velour pads.

Now I know that Audio Zenith mods are slightly different is there is not a peak in the high-mids, and rather sloped in that area instead and adds some air up top. However, I felt the velour pads had a bit more air and maybe not as much bass tightness. I even measured them and the bass was only off by a db or two in the bass.

You can also find Tyll's measurements on the PM-1 where it shows more slope in the bass by a db or so with the velour pads. The PM-2's and PM-1's though were kind of darker on top so some air would be welcome. The deeper memory

Shure pads have are not memory foam, less dense than the stock PM-2 memory foam, and I can see why they might not have a good tonality.

 

I just got a brand new PM-2 from Ebay and I think they sound like garbage. One of the worst orthos I have heard. My impressions are so far off from what I've read. Based on the impressions of the PMx2 I thought these would have lots of mod potential but they don't. Not my pair anyways.

The distortion is easy to hear across the whole frequency range but especially in the midrange. It sounds dirty and "low-fi' in that way that distortion does. And it is not fixed by damping the driver like other orthos. I contemplated various ways to stabilize and reinforce the driver, but it's open on the whole back of the driver making any kind of reinforcement impossible.

I've damped the driver to the point of being over damped and still cannot get treble extension out of them. It's rough and cut off and makes cymbals sound like cardboard. The 1978 NAD RP18 sounds much better than this in every way and is much cheaper as well. The Yamaha YH3 which I have about 6 pairs of which each cost me 40$ sounds much better than this.

I feel like I just threw away 500$. I can't sell them or return them as I've removed the stock damping.

Based on what I;m hearing I do not recommend this headphone to anyone. But I guess both drivers in my pair could be equally defective and matched that way? Seems unlikely but I guess it's possible.

I'm guessing the problem is that the diaphragm is very large, but is only driven by very small magnets on. one side of the diiver. The LCD-2 must have 20x more magnets than this driver. A small driver would be ok, but a huge driver, only driven by magnets in the center I think leads to the diaphragm moving in unwanted ways all round the driven area causing distortion.

Heres a picture of the diaphragm and magnet array.



It's really gorgeous, I think I might frame mine on my wall since I won't be listening to it at all.

Here's what I believe the problem is. The entire oval shape including the circle and all the criss crosses is the diaphragm and is moving. But it is only driven by these two magnets in the middle of that large diaphragm and only on one side of the driver



There is no other driver I've seen designed with so much diaphragm space with no magnetic force controlling it. Even the center circle has less magnets on it than something like a 1978 Fostex T10 which has a driver similar in size to that circle alone, but has at least twice as much magnet and on both sides of the driver. And it doesn't have that whole extra space outside the magnets flopping around.

Here's a picture of the T10 diver



Look how much more of the diaghragm is covered by magnets, and on both sides. There are small slots for the sound to move through, not huge gaping areas. And the enitre surface of the diaphragm is covered by this magnet density. This driver about the same size as the circle of the PM-2 driver.

Here is a picture of a Yamaha driver. Same story here. That whole thing is one giant magnet with tiny holes for the sound to move through. Even if the PM-2 is using much stronger magnets, it has to be a much more poorly controlled diaphragm in comparison.



I don't understand the design or the sound impressions of this headphone.

 

Damn that's brutal. Definitely interesting how different our impressions can be about the same headphone.

 

Epic post rd. Sucks to hear about your gambling loss. I was looking at dead battery Drop Pandas to use wired on eBay for $100 but decided not to risk. The Panda will always be imbalanced because left/right enclosures are not symmetrical due to electronic components. Brand new ones appear to be very finicky and brick themselves with each new firmware update. Which is too bad because the parametric eq feature would be a lot of fun.

Send PM-2 on loaner tour rd? Okay, I just want to hear. I cannot offer to buy at that price though so dont get hopes up.

 

I could be wrong, but I thought I read Audio Zenith upgrades the magnets.

 

illl happily loan you my PM-2 with the best damping I got before just giving up. I didn’t spend much time honestly because there aren’t a lot of options here and the treble can’t be pulled up from the void.

 

Thanks! Ill send whatever you might want to borrow in return. I’ll have an ETA Supra coming soon … ! PM me when youre set.

Did you try velour pads?

 

Audio Zenith also used ovens for some reason. Not sure if this is for other than softening the plastic diaphragm to tighten it. The PMx2 is a completely different sounding headphone than PM-2 or PM-1.

 

Nope, not going to invest another penny into this headphone. Except mine came with a defective 1/4" cable. I ordered a new one from Audiophile Ninja. As soon as it gets here I'll pm you and send it over.

 

@rhythmdevils,

I think you're not wrong with your impressions and your headphone is not defective. You are hearing the prototype Empyrean sound. It is also a low-fi beats to chill to type of headphone. I am one of those people who likes the PMx2, but not at that price. The $500 you paid, is what I would pay for the AudioZenith version. It was very comfortable, had some bass and I could put it on at anytime and not worry about fatigue. I've never claimed it to be a technical marvel, but it was enjoyable for me for my own reasons.

 

Just wanted to throw this up here as something that you may want to check out. According to Tyll, their are magnets on both sides of the diaphragm. I am currently listening to a PM-1 and it appears that there are magnets on the earpad side just hidden by the black rubber and center circle piece. Based on some small interactions with a paperclip they are there, just fairly week.



I have been working with this PM-1 for a few days to modify it to become a close cousin to my PMx2 and it is getting closer. The pads make a very large difference and of course the good ones are very hard to get. The stock or Alt leather pads are best, the alt leather bring up the treble a good amount.

As for materials, I have used a combination of the stock felt ring on the back of the driver, DCA tuning kit black foam,then finally some wool/cotton blend material about a 1/4 inch thick, and then some acoustic dampening foam and cotton balls lining the inside of the cup walls and filling in the area next to the DCA foam. I have removed the little half circle that sits on the driver ear side, and have kept the foam donut on the front.

I had covered all the holes with micropore tape, but this created strange truncated bass that sounded like the diaphragm was hurting itself. So I ended up with just the holes down below covered with rubber plugs. I added some additional rubber plugs on the back of the driver to add force to the back of that backplate once all closed up.



So far I am enjoying the setup. Its added some bass impact and treble is clean and brought up. I plan to keep playing around with it and will post here as I do.

Sorry to hear you are not enjoying them.

It is rumoured by AZ that Oppo sent out cherry picked units for all reviewers and that is why the reviewers experience is different from others out there. Pretty sure Alex said that he had a hard time finding pairs that had driver matching as well as they claimed from Oppo.

 

It is so funny, because I was just looking at these yesterday, so it is fun to share since we are all on the same subject...

Basically, here an FR of what is on the Audio Zenith site of the PM-2 and PMx2



I had to do a screen grab, so pardon the bad quality and button. However, it seems they appear flatter than they actually are. Here is Tyll's measurement of PMx2:



And this is how they down. Down in the mids for a mellow sound, quite linear in the bass, and a bit of air on top before they drop off.

And to look at how they compare to the PM-2 and PM-1 and show the difference in the pads, here is Tyll's measurement of both the PM-2 and PM-1 respectively:

 

I've heard this too, that it was a controlled heat shrinkage to tighten the diaphragm.

Not necessarily. The old Fostex and Yamahas had weak magnets and shoved the same poles into each other, in effect squeezing/forcing the magnetic field lines to radiate outwards from the center. In theory yes it works, but in practice very hard to guarantee symmetry and consistency. Magnetic strength was also not perfectly even across those old magnets. I don't have one anymore, but you could see the effect with some iron filling on paper or with magnetic film.

 

I looked again at the PM-2 and it does look like it has magnets on both sides of the driver, but it doesn't change much.

Even if this is true, it doesn't change the point I'm making - that the magnetic coverage of the disaphgragm on the PM-2 is much much lower than any ortho in history AFAIK and it's not even close. Even if what you say is true about the vintage orthos, the coverage and magnetic strength is going to be stronger and more even across just that inner circle with the vintage orthos, let alone that entire oval diaphragm. There is just a thin outer and inner ring on the PM-2. It doesn't even compare to the vintage orates and the weaknesses of the old tech I very much doubt make up for this difference in coverage. The PM-2 magnets are also thinner while we're at it....

The Yamaha and Fostex drivers had no problems due to lack of uncovered diaphragm surface area, I really don't understand this driver design leaving so much of the diaphragm uncontrolled. It has to be the cause of the distortion. And likely the iniability to produce clean treble as well (tiny movements in the diaphragm require control from the magnets).

I haven't put the drivers into an EZ bake oven... I don't think the design warrants such modification attempts.

 

I challenge some of the conclusions that you are drawing here.

The image that @Ksorota posted showing the magnet arrangement is just as capable of providing strong magnetic fields as the old Fostex ways. I'd even argue that the old Fostex way is a "bad" way to do it while the newer way is superior and provides for more consistent magnetic fields. The old way with all that coverage also means significantly reduced "effective" diaphragm area. One could make the converse argument that Oppo made the design decision to have as much exposed diaphragm as possible.

The fact that the Oppo sensitivity is nearly an order of magnitude higher also dispels some of the notion that the magnetic field is not strong enough.

You keep saying the driver is uncontrolled. It was well known when this first came out that the driver did have ome specifically weird distortion or decay peak in the mids. Maybe you're super sensitive to this and extrapolating that into thinking the entire thing is wonky?

 

Not the best image, but I tried to get a screenshot of a modded T10 and PM2 next to each other

You can look up the innerfidelity all graphs pdf here:
https://www.dropbox.com/sh/d7a9pho6d71doan/AAAXJBpws7IjS4ln1WoKU0RMa?dl=0

 

I knew you would give a positive response to these pads. I also agree with your assessment that Oppo had to create clear water between the 1 and the 2. 'Overall tonality and balance' - all the reviews have the same take on the Oppo 2 - enjoy.

 

rhythmdevil - your opinion of the Oppo 2 is so different from all others that I have seen and checked out every view I could find before buying that it seems rational to say that you have a 'Friday afternoon job' - sheise passiert/shit happens.

 

I will say that some higher level of distortion could probably explain why I do think there are definitely headphones that beat the PM-2 for resolution and detail. Clearly though, the level of distortion isn't bothering me like it is @rhythmdevils which I suppose could be explained by higher than usual unit to unit variation in PM-2s, but more likely it's just down to the ever-present fact that our subjective listening experiences can vary wildly.