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Oppo PM-1: A New Planar Magnetic Headphone! - Page 98

post #1456 of 2548

Small dynamic drivers in open cups. Grados just start puking everywhere, not just in the bass, when pushed hard.

 

But I'd like to see PM-1 THD figures zoomed in 0.001% to 10% on a log scale at 87dbA. That would a very meaningful measurement / visualization which could, but not necessarily explain some of the things which I did not like about them.


Edited by purrin - 4/15/14 at 6:38pm
post #1457 of 2548
Quote:
Originally Posted by bbutterworth View Post
 

I wanted to respond to some of the comments made here about the About.com Stereos measurements. I think too much has been made of the distortion I found in the Oppo PM-1 at 100 dBA.

 

I have measured 174 headphones at last count, and with about half of those, I also had some of Sound & Vision's writing staff do subjective testing of the headphones. Only in the most extreme cases did measured distortion correlate well with listener impressions. Usually that was with products such as cheap noise cancelling headphones, which sometimes do have audible distortion problems. I have only very rarely heard panelists complain of distortion problems with headphones at even fairly loud levels. I have measured numerous headphones with higher distortion on this test than I measured from the PM-1, and heard no complaints from listeners.

 

A test level of 100 dBA is very loud; I can listen to it, but I don't like to listen to it. And of course that level will vary at different frequencies due to the response of the headphone. So it might be as high as 110 dB or so with a particular sine wave frequency. (Even higher if a headphone has unusually large peaks and dips in the frequency response.) I chose this level because it's one that allows me to objectively differentiate the output capabilities of headphones. It's somewhat like CEA-2010 subwoofer tests. Almost no one pushes a subwoofer to 120 dB, but we have to push the subs to that level in order to measure differences in output capability.

 

I'm reluctant to judge any headphone by its measurements, or even to say what a "good" measurement is. There are a few I've measured that are clearly bad, with huge peaks and dips in FR, very high distortion, high sensitivity to amplifier output impedance, etc. But otherwise, I've so far seen at best an occasional correlation between listener perception and headphone measurements. And that's with frequency response. CEA-2010 perhaps excepted, our understanding of audio transducer distortion measurement and how it correlates to listener perceptions is at a relatively primitive stage. This is part of the reason why we don't see a lot of published audio transducer distortion measurements.

 

Based on what I've heard of the PM-1 (soon to be published on About.com Stereos -- shameless plug), there are good reasons why you might choose the PM-1 over a competitor or a competitor over the PM-1, but distortion isn't one of them.

 

Thanks for the comments. I personally like HD sweeps referenced at 90 dB at 1 kHz that show all harmonic products up to 5th order over all frequencies. This format contains most information, IMO, and is how I measure speaker drivers.

 

One thing to add: Do not generalize too much about correlation between measured performance and audibility. Scientific grounds on this issue (how audible particular levels and patterns of nonlinear (even linear) distortions would be to human ear under various, realistic conditions) are very weak at the moment. In fact, subjective preference could also be more or less standardized, though not as accurately as objective criteria, IF a lot of psychoacoustic experiments were performed. But this kind of data will never be enough since people in academia are not interested in this topic. People will never be interested in such things unless all the more serious issues (e.g., treatment of cancer) are fully resolved. I think I am entitled to make comments like this as I am a cognitive psychology PhD with one of research interests being perception and psychophysics.

 

For this reason, objective measurements are what we want to use to assess high-performance audio equipment for their well-defined characteristics. Of course, measurements do not need to be perfect (or near perfect), which is not possible anyway, especially for headphones or speakers. But $1000 planar-magnetic headphones should exhibit as good or better linear/nonlinear distortion performance as/than leading dynamic headphones such as HD600, HD650, DT880, or K701. None of these so-called reference phones show 5% HD in the lower-mids, even at 100 dB.

 

InnerFidelity will post measurements soon. I will see if this anomaly is consistent across review samples.


Edited by Jay_WJ - 4/15/14 at 6:55pm
post #1458 of 2548

Guys, like I said before: Listen to some music with a pair and correlate that to any measurements. Talking about measurements without listening to the sound is almost a complete waste of time, especially to those people who want to read people's impressions and not a bunch of confusing technicalities. I'd strongly suggest that if you don't have either impressions or something useful to comment or ask about people's impressions then you hold back on posting and I'll open up Jude's original thread for all that discussion. :smile:

post #1459 of 2548

partly made in China and  in the phillipines as per OPPO Digital CSR

post #1460 of 2548

Back open. Some posts about measurements and whatnot have been moved here from the impressions thread.


Edited by Currawong - 4/15/14 at 8:13pm
post #1461 of 2548
Quote:
Originally Posted by pfillion View Post
 

I'm very tempted to buy them but the total price is killing me because I'm in Canada. (The total price would be $1457.33 CAD with the shipping + the customs + the usd-cad conversion.)

 

And I promised myself that I would never pay anymore more than $1000 for a pair of headphones.

 

I think that I will have to wait for the PM-2..

I  put my Order in from  in from British Columbia 1294.35 so i guess you get dinged more in Quebec Ce'st ridicule

post #1462 of 2548
Quote:
Originally Posted by Currawong View Post
 

Guys, like I said before: Listen to some music with a pair and correlate that to any measurements. Talking about measurements without listening to the sound is almost a complete waste of time, especially to those people who want to read people's impressions and not a bunch of confusing technicalities.

 

I will follow your advice as you are an Admin. But I do not think what you just said in the above is well-grounded judgment. Objective measurements are huge information and their interpretation can be very helpful for people to make judgment. Sometimes, proper interpretation of measurements is valuable EVEN without any listening (e.g., a single set of measurements conveys more information than 100 times of listening experience about a certain anomaly). 

 

If I were an admin and wanted to take action like this, I would be cautious and simply say the policy (impressions in one thread and other information in another, etc) without stating my own relative perspective.

 

 

Quote:
Originally Posted by Currawong View Post
 

I'd strongly suggest that if you don't have either impressions or something useful to comment or ask about people's impressions then you hold back on posting and I'll open up Jude's original thread for all that discussion. :smile:

 

I agree that some discussion is tangential. But that is more or less the nature of forum discussions. I will post comments, if any, about measurements here from now on.


Edited by Jay_WJ - 4/15/14 at 8:58pm
post #1463 of 2548
Quote:
Originally Posted by Jay_WJ View Post
 

 

I will follow your advice as you are an Admin. But I do not think what you just said in the above is well-grounded judgment. Objective measurements are huge information and their interpretation can be very helpful for people to make judgment. Sometimes, proper interpretation of measurements is valuable EVEN without any listening (e.g., a single set of measurements conveys more information than 100 times of listening experience about a certain anomaly). 

 

The problem is that you guys are clogging up a thread based on one guys measurements which can't even be compared to known headphones. The measurements are worthless without a known base. Give it a rest for a bit because you're all arguing about "what ifs" and making assumptions based on one chart. Take a minute to relax, it's just a headphone anyway. If you don't like it then you don't have to buy it. Heck Oppo has a 30 day policy, how about listening instead of looking at charts? Charts only mean so much.


Edited by keanex - 4/15/14 at 9:59pm
post #1464 of 2548
Quote:
Originally Posted by keanex View Post
 

 

The problem is that you guys are clogging up a thread based on one guys measurements which can't even be compared to known headphones. The measurements are worthless without a known base. Give it a rest for a bit because you're all arguing about "what ifs" and making assumptions based on one chart.

 

The About.com measurements are not as well-established as InnerFidelity's, but it is incorrect that the PM-1 measurements are without a known base. Brent measured quite a bit of headphones using the same methodology and condition, many of which have also been measured at InnerFidelity. It IS meaningful to compare the measurements with those made under the same condition, some of which are with known levels of linear and nonlinear distortion according to others' measurements. Most headphones measured at both About.com and InnerFidelity are consistent, for example, in their THD levels (only difference is the scale: One is linear and the other is log).

 

Quote:
Originally Posted by keanex View Post
 

Take a minute to relax, it's just a headphone anyway. ... ... how about listening instead of looking at charts? Charts only mean so much.

 

The OPPO PM-1 is a $1000 headphone, which only hard core enthusiasts will buy. What you just said above is what we call an extreme subjectivity view.


Edited by Jay_WJ - 4/15/14 at 10:37pm
post #1465 of 2548
Quote:
Originally Posted by Currawong View Post
 

Guys, like I said before: Listen to some music with a pair and correlate that to any measurements. Talking about measurements without listening to the sound is almost a complete waste of time, especially to those people who want to read people's impressions and not a bunch of confusing technicalities.

Amen...

 

I'm always interested in how a headphone measures, but I've never based a purchase decision on that and never will. This is not meant to be a knock on the HD800s, cause the time I've spent with them I really enjoyed. But I find it so interesting how many people I've come across who either fully admit they bought it because of how many people here on head-fi had them convinced it was the "best" headphone, or it was obvious from what they posted that it was almost due to some form of "headphone peer pressure" to buy it.  They THINK they're supposed to consider it the best headphone out there simply because others do, when there are quite a few who realize that they actually prefer something else. So in that sense, Amos is spot on, because especially when you're considering dropping that kind of money on something you're going to spend hours and hours with, you certainly owe it to yourself to place at least equal emphasis on how it sounds to YOUR ears, not just how it measures. 

post #1466 of 2548
Quote:
Originally Posted by purrin View Post
 

Small dynamic drivers in open cups. Grados just start puking everywhere, not just in the bass, when pushed hard.

 

But I'd like to see PM-1 THD figures zoomed in 0.001% to 10% on a log scale at 87dbA. That would a very meaningful measurement / visualization which could, but not necessarily explain some of the things which I did not like about them.

Please provide more details about your listening evaluation, especially about what you did not like.

post #1467 of 2548
Quote:
Originally Posted by Focker View Post
 

This is not meant to be a knock on the HD800s, cause the time I've spent with them I really enjoyed. ... ... Amos is spot on, because especially when you're considering dropping that kind of money on something you're going to spend hours and hours with, you certainly owe it to yourself to place at least equal emphasis on how it sounds to YOUR ears, not just how it measures. 

 

The HD800 does not have the best measurements. :wink_face:  Its linear distortion is higher than that of the HD600 or the HD650 by the standard of any target responses. Anyway, I got your point.

post #1468 of 2548

I have all the major cans.  The PM-1 are VERY, VERY GOOD.  They are a bit more fun and vibrant, less laid back than LCD3, but not fatiguing.  They're easy to drive, light, comfortable, come with great accessories, nice quality, and comparatively low price.  They cost only a little more than what HD700 did at release, and that is hilarious.  I may like these more than all my other headphones.  

post #1469 of 2548
Quote:
Originally Posted by Jay_WJ View Post
 
Quote:
Originally Posted by Currawong View Post
 

Guys, like I said before: Listen to some music with a pair and correlate that to any measurements. Talking about measurements without listening to the sound is almost a complete waste of time, especially to those people who want to read people's impressions and not a bunch of confusing technicalities.

 

I will follow your advice as you are an Admin. But I do not think what you just said in the above is well-grounded judgment. Objective measurements are huge information and their interpretation can be very helpful for people to make judgment. Sometimes, proper interpretation of measurements is valuable EVEN without any listening (e.g., a single set of measurements conveys more information than 100 times of listening experience about a certain anomaly). 

 

If I were an admin and wanted to take action like this, I would be cautious and simply say the policy (impressions in one thread and other information in another, etc) without stating my own relative perspective.

 

The measurements are useful for people who are used to listening and correlating, but for everyone else, we're getting some comments (I wont point out which ones) which are pre-judging the headphones as a result of mis-interpretation of them. Given that there are only a couple of members here (other than manufacturers) who could be described as qualified to make comments, and the rest of us are talking out of our rear ends (including myself!) I don't really see that we are adding a great deal of information, but heading very strongly into mis-information territory, as people will parrot these comments elsewhere as fact.

 

I don't think it is unfair to say something like "This graph/plot is interesting and a wonder if feature X on it is going to mean a problem with [some or other aspect of] the sound" but the way I've seen some people phrase things (eg: Talk of ringing at 200 Hz meaning a pair must be defective -- I mean really?) is getting a bit over the top. :smile:

 

I'm going to see if I can't arrange to borrow a pair and listen for myself. I guess they'll be polarising like the LCD-2s were, but given they are closer to the size of regular headphones they might be more popular. 

post #1470 of 2548

The sound is on par with LCD3, with a bit more bass weight, in terms of what echelon of sound quality we're talking about.  I'm not great at comparing stuff, I just know what I like, and I have enough bad headphones here (about 12 on my Wall of Suck) to know when a headphone deserves to be parked near my amp rack, and this is one, along with Alpha Dogs, LCD3, HD800, and K812.  I think everyone on this board would be honored to own a pair.  I'm having a great time here listening, and if you all actually read the about.com thing it's largely positive stuff except for 6db of distortion in a narrow part of the frequency band.  

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