Oppo Ear-Pads Listening and Measurements

It's super-duper when headphone manufacturers include the community when developing products...for the enthusiasts. It makes for great entertainment and developing interest among the headphone faithful. But, whooo boy, what a chore for the manufacturer. Herding cats is an understatement.

Many others noted as I did in my Oppo PM-1 review that the headphones were somewhat overly polite. It's a sound I tend to like, but a coloration none the less.

So, with the lower cost PM-2 model about to be released, the folks at Oppo decided to go back to the drawing board to see if things might be tweaked a bit. The result was a slightly brighter pad design, both for the PM-2 and an alternate leather pad for the PM-1. Here's a quick look at the pads.


Original Velour pads for the PM-1.

Of the two pads that originally came with the PM-1, I preferred the Velour pads. To my ears they seemed to have a bit more meaty bass and a tad more treble.


Original leather pads for the PM-1.

The leather pads were quite close to the velours, but they seemed more polite...a direction that these cans really don't need to delve into further. Notice these pads have holes on the inside of the pad all the way around. These hole provide a controlled leakage that tends to even bass response—they lessen the bass hump and changes to bass response with changing seal of the pad. Unfortunately they also lessen bass response overall by a small amount. The velour pads don't need the holes because the fabric naturally leaks. Notice that both the stock leather and velour pads have a small donut of felt behind the pad to damp the cavity resonance in front of the driver.


New Alternate Leather PM-1 Pad.

Here's the new alternate leather pad for the PM-1. These pads now come with the PM-1, which still includes both original pads...yes, buy the PM-1 now and you now get all three pad types. Owners of the PM-1 who purchased prior to these pads becoming available can request a free pair of the pads here.

To my ears these pads are superior to both original pads, delivering a bit more low-treble energy and giving vocals a bit more presence. Even though I'm fine with a bit of "veil" I do prefer these pads to the original ones.

Notice these pads do not have the felt donut on the rear, and there is a section of the inside of the pad that doesn't have any holes in it. This brings the bass up just a tad from the original leather pads.


Stock PM-2 protein leather pads.

The PM-2 is a lower cost version of the PM-1 and is very much the same except for differences in materials used and accessories included with the purchase. A complete rundown of the differences between the two models can be seen here.

The PM-2 pad uses the same design as the PM-1 alternate pad except for using less costly materials. Note that it too has the same inside hole pattern as the PM-1 Alt pad.

Generally, I found this to have a similar sound character as the Alt pad but a tad brighter, and bit less refined sounding. Of course, that could just be me knowing the materials are less costly and projecting, but measurements bear out the observation. I'll dig into this a bit more as I listen to the PM-2 and consider it for review. (Which is quite likely.)

All these pads are close enough in character to be quite similar, but different enough to warrant a good hard look. So I did a bunch of measurements. The following graph shows the averaged raw frequency response of the Oppo PM-2 measured with all four pads. Plots are aligned at 400Hz.


Averaged raw frequency response plots of PM-2 with the four available pads.

For me the most important part of this plot is in the region between 1kHz and 3.5kHz. This low-treble area give presence to vocals. When lacking it results in a veiled sound, giving the impression of more distance between the voice and listener...at least that's how I hear it. You can see that the PM-1 Alt and PM-2 pads do a much better job of providing a linear rise to the peak at 3.5kHz. The Harman response curve would actually see the starting point of this rise even lower in frequency—imagine connecting the 600Hz peak to the peak at 3.5kHz. While the PM-2 pad might actually be more neutral in the area between 1-3.5kHz (sorry, not sure), the subsequent more severe dip at 7kHz is troubling. Ideally, the area between 3.5kHz and 10kHz should not have a valley at all.

I'll go into more detailed listening notes on the two new pads when I do the PM-2 review, but for now I will suggest to those who own the PM-1 it's a very good idea to take Oppo up on their very generous offer for free PM-1 Alternate pads.

Mr.TAD91's picture

Interesting article and I've experienced similar results with switching earpads. Your review on the OPPOs was actually spot on - You put them in a good light as coloured headphones, and that's pretty tough to do!

tony's picture

I own two Sennheiser RS 120 wireless systems , one for mp3 books and one for general work round the house . I also own the HD 600s for best listening ( love em ) . My Asgard 2 powers one pair of RS120s and the HD600s . Using the iTunes rating system of stars I can relate the stock RS120s will play 5 Star music to 4 Stars ! However , I found an old pair of Over-ear JVC cans at a Garage Sale ( broken and cheap , $1.00 ) who's ear pads fit the RS120s resulting in raising their performance level half a Star . Now , I almost forget that I'm not wearing the big HD600s while enjoying a recent Joshua Bell or some other great piece of music . Pads can make an important improvement , now I know , for sure .
I'd like to try other pads for the HD600s but they are so beautiful sounding now I don't want to mess with them .
Jason at Schiit is about to release another Amp , this one has major power , I hope you get one to try out , I love the Schiit stuff and am hoping Dr.Mike gets to working on a "proper" R2R Dac with a nice Clock .
Thank you for all your hard work , probably beats sitting in Airports and dealing with grumpy Plant Managers ( I did the road warrior stuff too , waking up in the early A.M. not remembering what City I'm in , oh-my , never again for me )
Thanks ,
Tony in Michigan

Tyler Schrank's picture

The HD600 is a truly excellent headphone, and I actually tend to prefer them over the PM-2. As far as other pads you can try on the HD600, the HM-5 velour pads supposedly work well and aren't too far off the stock pad's sound. (A bit over $20 for the pair)

tony's picture

Thank you for being helpful . I suspect the HD600s outperform any of my High-End Loudspeaker/Amp combinations ( I was in the Business and owned quite a few superb systems ) . Now , today , I'm hunting for an Active Loudspeaker that tries to perform at or near the HD600 level , I'm looking at the ATC stuff from England , the Focal stuff from France and the Gelelic stuff from Finland , the Mid-field or Near-field will do fine . Delivering HD600 reproduction may be too much to ask of a powerful system but I hear nice things about these outfits quality standards , we shall see .
So in summary : the HD600s are acting as my Gold Standard for further purchases , a very high standard indeed , imagine trying to discover stuff to equal the Audeze or Stax .
Thanks again for the help ,

Tony in Michigan

poleepkwa's picture

I have not heard the others, but own Genelecs. I would suggest looking into the DSP series to emulate that linearity that the HD600 have.

tony's picture

Thank you Sir ,
It seems that buyers of Genelecs require quality and Company integrity from their equipment , you actually owning a pair speaks volumes about the product , thank you for the recommendation .

gvigers's picture

Yeah for Active Speakers !
I own a pair of ATC SCM 100's and they are superb. The midrange is particularly good. One of the reasons I'm looking at headphones is that I can't imagine finding a better pair of speakers :) I'll definitely check out the HD600s, so thank you. The ATCs are expensive, but you can occasionally find them used. Happy listening!

Tyll Hertsens's picture
I'll let Hans' pad answer speak for itself, but yeah, love the HD600...what a classic!

Re the RS120: That is also a great little wireless set-up. People looking for a good rig for TV watching late at night take note, the RS120 is a really good low-cost solution.

Tyler Schrank's picture

Will you, by chance, be doing these same pad measurements on the PM-1 as well? Just to verify that the PM-1 and 2 are indeed supposed to sound the same given the same pads. I am curious if Oppo made some other, internal changes to the PM-2 along with developing and providing a new pad.

Tyll Hertsens's picture
Yup. I figured showing the differences in the pads was worth posting as it will be a little while before I'll have the chance to do the measurements and comparisons of the two models. For the PM-2 review I will dig into any differences that might exist between the PM-1 and PM-2. I'll be chatting with Oppo on the differences as well.
Tyler Schrank's picture

Sounds good, Tyll. Looking forward to it! Appreciate everything you do for the community. :)

elinbal's picture

When is a review arriving?

poleepkwa's picture

Excellent stuff! I was wondering hoping that would you have interest too do this earpad measurements also for the V-Moda M100?
I first heard about the "improvement" on Digital Audio Review (DAR) and yes they do change the sound for the better when swopping the XL-pads in.

Corpsemaker's picture

It's a little of topic, but I'm sure there are others interested as well.. Tyll, do you know (at least approximately) when can we expect the Mr. Speakers Alpha Dogs review?


Impulse's picture

From a comment he made in an earlier review I got the impression it was coming up on the review queue pretty soon, but maybe he got sidetracked by other stuff (like the Oppo pads, which was an interesting read in and of itself).

I'm looking forward to it too tho, and to the comparison with the Mad Dog Pros (since impressions on later seem harder to come by than on regular MDs or even ADs).

Corpsemaker's picture

That is the only reason I asked (the earlier review comment about an upcoming review). There's probably gonna be a comparison to LCD-2 and PM-2...

The Federalist's picture

Considering 99% of headphone manufacturers give you one option for pads short of using wadding a hole puncher or acoustic felt... Oppo offering a sort of tuning device is pretty cool.

As a bit of a rant I think they've gotten pigeon holed rather poorly by the community... The PM1 is flat out better than the LCD2... It shines a light into a very dark shadow that the LCD2 (rev 2) casts up top and Though it may not have the absolute lowrider bass of the LCD2 but comes across as more natural and less colored to me... Couple that with the ability to drive it easily from a portable amp or handheld and aesthetics that don't look absurd out in the open and it really is pretty amazing. Closest i have seen to a true high end headphone that can be tethered to an iOS device and make the trip on the metro line.

What I don't get, and its not directed at you Tyll because I think you were very even handed a thoughtful in your PM1 review. But the LCD2 is far more veiled and far more colored but in general has been fawned over by the community endlessly... It has been a darling of Head-fi for years. Oppo has more air, i.e. Is less veiled and is overall more natural, is easier to drive and looks better and peoples response has been subdued if not outright critical despite both occupying the same price point.

I suppose maybe people's standards have gone up or maybe I'm tin eared or something it just seems like certain brands get the proverbial blessing and others don't

lukeap69's picture

You have been reading head-fi too much :)

(PS - I am a PM-2 owner.)

Tyll Hertsens's picture
A lot of that kind of depends on which version of the LCD-2 you're talking about. The current Fazered version is much more open up top.
The Federalist's picture

And I don't mean to deride Audeze in any way. I think the LCD2 is fantastic, I use mine daily. But I do think the PM1 is top to bottom more natural. And I do think you fairly came to that conclusion in your review Tyll, slotting it right with the LCD2. Which is why I come back here over and over because I find my experiences line up with your review impressions. Your voice can be trusted.

But Considering how the portable market has blown up in recent years if you said at any time in recent years that you could have LCD2 quality sound in a portable friendly design with sensitivity to match. Now add that you can have that sound, with a few more pieces of plastic for $699 vs. the typical $1k+ entry fee... I would expect the community to be welcoming.

But my sense is, and Luke is right its probably from spending too much time reading admin reviews and posts at Head-fi, but the sense I get is that the "in crowd" is purposefully looking for things to be critical about with the new Oppo products.

Anyway, it's just headphones. I suppose there is no need to be getting my noise out of joint.