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Oppo PM-1: A New Planar Magnetic Headphone! - Page 103

post #1531 of 2548
Quote:
Originally Posted by bigshot View Post

Treble stops around 8-9kHz. If you take your favorite song and dial out everything above 12kHz using an equalizer, you probably won't hear any difference at all. Like I say, it's important to know what sound corresponds to what number.

The timbre of an instrument depends on harmonics. Just about all of the audible harmonics in instruments fall below 12khz. A roll off over 12kHz is likely only going to affect synthesizers and cymbals, and even then, probably not in any audible way.



As for amps vs headphones... Just about everything between amps and transducers are different. Solid state amps are pretty much all audibly transparent... ruler flat response, no audible distortion, plenty of dynamics. But transducers are an entirely different kettle of fish. Response deviations of +/-20dB are common. Distortion as high as 4 or 5%. Frequency extension that cuts off 2 octaves at each end... Specs like this aren't really surprising.

The reason that we put up with specs in headphones and speakers that we don't have to with amps or players is because we don't have any choice. It just isn't as easy to design something that produces mechanical sound to the same specifications as electronics or digital audio.

The specs on the Oppo PM-1 are fantasic in all the places where most normal headphones fall down. The fact that they don't reproduce frequencies totally accurately that aren't even present in music doesn't matter nearly as much as what they do well.

The main frequencies stop at 12k. Secondary harmonics do not. It's shown in that chart you posted to. See how some of them fade as high as 16 kHz? They have response up there and reproducing that response is important for timbre.
post #1532 of 2548
Quote:
Originally Posted by tinyman392 View Post

The main frequencies stop at 12k. Secondary harmonics do not. It's shown in that chart you posted to. See how some of them fade as high as 16 kHz? They have response up there and reproducing that response is important for timbre.

I apologize. I posted a low resolution image there that might be confusing you. A kind reader pointed me to a higher resolution version, so I replaced it.

If you look at the chart, the black lines are fundamentals. The piccolo goes up to about 6kHz. The shaded lines are the audible harmonics. (I'm guessing three levels of harmonics at the very least.) A few of those harmonics lines go above 12.5kHz, but only by about two notes on a piano... The violin, whose harmonic content above 12.5kHz is at a very low volume level compared to the rest, and cymbals where frequency masking would likely completely obliterate stuff above 12.5.

Fundamentals go up to about 5kHz on the average and audible harmonics go up to about 12kHz. Above 14kHz or so there is absolutely nothing to hear in music. Take a good digital equalizer and your favorite song and start ducking out 14-20kHz. You'll see that it makes no audible difference at all. In fact, you'll probably have trouble detecting a difference if you roll everything above 10kHz off.

One more thing to put the Oppo specs into context... It isn't a brick wall above 12.5kHz with the Oppos. That's just where the roll off starts. To find a set of headphones that is flat out that far is very remarkable. Most headphones start falling apart an octave lower at least.
Edited by bigshot - 4/17/14 at 11:58am
post #1533 of 2548
I actually agree with big shot here. Listen to only those freq in a song and you'll notice it will probably only be recording noise etc--things you don't even want to hear.
post #1534 of 2548
Saying that a drop off at 9khz is ok because treble doesn't go past 12khz is not only a silly statement because there is a 3khz gap but also as I've stated before(and recently verified with sinegen) I can hear to 20khz and while THAT is a mosquito buzz, from 10-15khz there is a lot of data and harmonics, saying there aren't is seriously misguided, none of us are saying these are bad headphones, the Audeze non fazor have a treble rolloff that gives them a unique signature that many are a fan of.

We already know that the pm1 does a lot of things that other orthos don't do, being lightweight and having >100 sensitivity, and it isn't surprising that something had to have been sacrificed to achieve that, treble rolloff seems the least objectionable downside, but it is a downside nonetheless. What's funny is the FR reminds me of single BA in ears, where they are very accurate but don't quite have the range of dynamics, and they either pick treble or bass to roll off, most people prefer the latter to the former.

I still want to hear the pm1s, I just doubt they would be for me in the same way as I'm not a fan of audeze headphones, the HD800 and hifimans are more my style, and I feel like the oppo is more a complementary flavor than a direct competitor.
post #1535 of 2548
Quote:
Originally Posted by bigshot View Post

Most headphones start falling apart an octave lower at least.

Most headphones don't cost $1100, and ones that do show similar or better treble extionsion.

It isn't necessarily a bad thing, these headphones will not be fatigueing in the slightest.
post #1536 of 2548
Quote:
Originally Posted by Ultramus View Post

Saying that a drop off at 9khz is ok because treble doesn't go past 12khz is not only a silly statement because there is a 3khz gap but also as I've stated before(and recently verified with sinegen) I can hear to 20khz and while THAT is a mosquito buzz, from 10-15khz there is a lot of data and harmonics, saying there aren't is seriously misguided.

By my measurements, the Oppo was flat out to 12.5kHz, not 9kHz. Whenever you get in that upper area, there is more chance of error in testing, and compensation curves for human hearing can make things complicated. I'm betting that the 9kHz rolloff measurements aren't accurate.

The first beta set of Oppos I got rolled off around 8 or 9. But they corrected that. I wonder if they were working with an older version of the cans?

Just because you can hear to 20kHz, it doesn't mean that those frequencies exist in music. Try the equalizer test I mentioned.

The difference between 10,000Hz and 15,000Hz is a half octave... four notes on the piano... the same range as from 20Hz to 30Hz. It really isn't a lot of data, and most musical instruments have harmonics below that. Look at the chart. You'll see.

Frequency extension is one of the least important aspects of sound quality in modern home audio components.
Edited by bigshot - 4/17/14 at 12:11pm
post #1537 of 2548
Quote:
Originally Posted by bigshot View Post


By my measurements, the Oppo was flat out to 12.5kHz, not 9kHz. Whenever you get in that upper area, there is more chance of error in testing, and compensation curves for human hearing can make things complicated. I'm betting that the 9kHz rolloff measurements aren't accurate.

The first beta set of Oppos I got rolled off around 8 or 9. But they corrected that. I wonder if they were working with an older version of the cans?

Just because you can hear to 20kHz, it doesn't mean that those frequencies exist in music. Try the equalizer test I mentioned.

The difference between 10,000Hz and 15,000Hz is a half octave... four notes on the piano... the same range as from 20Hz to 30Hz. It really isn't a lot of data, and most musical instruments have harmonics below that. Look at the chart. You'll see.

Frequency extension is one of the least important aspects of sound quality in modern home audio components.

Aight -_-

It is by no means a bad thing having a roll-off at 12.5khz. Again, preference. I'd rather see it extend down to 20 hz and up to 15 khz but that's just me. I am looking elsewhere.

FE being one of the least important thing is something I just won't comment on, because I find it a silly statement.


Edited by conquerator2 - 4/17/14 at 12:31pm
post #1538 of 2548
Quote:
Originally Posted by bigshot View Post


By my measurements, the Oppo was flat out to 12.5kHz, not 9kHz. Whenever you get in that upper area, there is more chance of error in testing, and compensation curves for human hearing can make things complicated. I'm betting that the 9kHz rolloff measurements aren't accurate.

The first beta set of Oppos I got rolled off around 8 or 9. But they corrected that. I wonder if they were working with an older version of the cans?

Just because you can hear to 20kHz, it doesn't mean that those frequencies exist in music. Try the equalizer test I mentioned.

The difference between 10,000Hz and 15,000Hz is a half octave... four notes on the piano... the same range as from 20Hz to 30Hz. It really isn't a lot of data, and most musical instruments have harmonics below that. Look at the chart. You'll see.

Frequency extension is one of the least important aspects of sound quality in modern home audio components.

What about any music that has synthetic components to it (any genre that is not pure instrumental/vocal)? Or films/videos/video games with non-music sounds that involve very high frequencies (gunshots, environmental destruction, hard materials grinding against each-other, explosions, aliens, etc literally a million different things)?

 

Again, your point is backed up by a very narrow field of view, and you're preaching it like it's a fact.

post #1539 of 2548
The most important aspect of sound quality is the balance of the response throughout the frequencies that music inhabits. At most, that's 30Hz to around 15kHz. Transducers that can do that are few and far between.

Second most important is distortion. Headphones can do very good, with distortion around 1-2% or so, around the threshold of audibility with tones. But some types of distortion are worse than others. It's possible that as much as 5% can sound OK in music if it's in the right place in the harmonics.

Dynamics is third. A lot of headphones do a good job here. I see more problems with speakers than headphones with this.

Timing is fourth. Things have to be pretty bad to reach the threshold of audibility. Except again for speakers where room acoustics can cause big problems.

Frequency extension that covers frequencies that don't exist in recorded music is dead last in importance. It's good to cover the full range of human hearing if everything else is already covered, but it isn't very important if those frequencies don't exist in the music you are listening to.
post #1540 of 2548
Quote:
Originally Posted by jerg View Post

What about any music that has synthetic components to it (any genre that is not pure instrumental/vocal)? Or films/videos/video games with non-music sounds that involve very high frequencies (gunshots, environmental destruction, hard materials grinding against each-other, explosions, aliens, etc literally a million different things)?

Take that kind of content and do the equalizer test, rolling off everything above 15kHz and tell me what you find out. I know what you'll find... almost nothing at all, even places you would expect to find it. Theory and practice can be two different things. Having equipment that reproduces the full range of optimal human hearing is great in theory. But I am talking about the things that matter in practice. Frequency extension into the top half octave of human hearing doesn't really make any difference.

The stuff happening in the middle is MUCH more important, and getting that right is a lot harder than you might imagine if you focus on the bleeding edge of human hearing.
post #1541 of 2548
Quote:
Originally Posted by jerg View Post
 

What about any music that has synthetic components to it (any genre that is not pure instrumental/vocal)? Or films/videos/video games with non-music sounds that involve very high frequencies (gunshots, environmental destruction, hard materials grinding against each-other, explosions, aliens, etc literally a million different things)?

I just did an experiment with WinAMP and Shibatch SuperEQ plugin in which I cutted off all frequencies except 14kHz-20kHz region. I played my few FLAC-quality electronica songs from different albums and I couldn't hear a thing. Also there was no green bar in my Windows sound mixer which would indicate that something is being played. Therefore my conclusion is, that at least for electronic music, there is nothing up there.

post #1542 of 2548
Quote:
Originally Posted by conquerator2 View Post

Again, preference. I'd rather see it extend down to 20 hz and up to 15 khz but that's just me. I am looking elsewhere.

Do you really think you can tell the difference between music that rolls off at 12.5kHz and music that rolls off at 15kHz? A gnat's hair is bigger than that. I bet you can't even do that with a direct A/B line level matched comparison. That's just one note on a piano's difference, and up there you have no perception of musical notes any more.

The high end of an octave is about double the frequency of the low end. 10kHz to 20kHz is one octave. Human hearing spans around 7 octaves. Why would the top 6 or 7% of your hearing range matter so much, especially when those frequencies don't really exist in recorded music and your own ears are rolling off in that range anyway? Why is it so absurd for me to say that the balance of 94% of the frequencies we hear matters more than the top 6%? That seems completely logical to me.
post #1543 of 2548
Quote:
Originally Posted by bigshot View Post


Take that kind of content and do the equalizer test, rolling off everything above 15kHz and tell me what you find out. I know what you'll find... almost nothing at all, even places you would expect to find it. Theory and practice can be two different things. Having equipment that reproduces the full range of optimal human hearing is great in theory. But I am talking about the things that matter in practice. Frequency extension into the top half octave of human hearing doesn't really make any difference.

The stuff happening in the middle is MUCH more important, and getting that right is a lot harder than you might imagine if you focus on the bleeding edge of human hearing.

I thought we're talking about 12.5kHz, not 15kHz. 

post #1544 of 2548
You do understand that the every harmonic of any note above 7.5khz exists past 15khz, treble extension isn't about the fundamental frequency, it's about all the high treble notes sounding correct because their harmonics are still present, no one would buy a piano or violin that couldn't produce sound past 15khz, let alone 12.5.

There exists no argument that a steep treble rolloff is desirable, either there isn't any important sound there which you say, and having the extension is benign, or there is reason as we say, and it's malicious, no scenario exists where it is beneficial, according to your own logic.
post #1545 of 2548
Quote:
Originally Posted by bigshot View Post


Take that kind of content and do the equalizer test, rolling off everything above 15kHz and tell me what you find out. I know what you'll find... almost nothing at all, even places you would expect to find it. Theory and practice can be two different things. Having equipment that reproduces the full range of optimal human hearing is great in theory. But I am talking about the things that matter in practice. Frequency extension into the top half octave of human hearing doesn't really make any difference.

The stuff happening in the middle is MUCH more important, and getting that right is a lot harder than you might imagine if you focus on the bleeding edge of human hearing.

I for one am glad that this information is staring to spread into the wider Head-fi community.  I know how shocking it can be to beleive one moment that the specs on is accustomed to are solid, and then the next moment be presented with information that, once confirmed as being accurate, is quite upsetting.  As a bassisgt, finding out I don't need a cab capable of reproducing 30 Hz on my extended-range bass was embarassing at the very least. But that is a different argument for a different forum...

 

This is one reason I have the PM-1 on my radar.  As usual, Oppo is not pandering, but is instead offering extremely high quality equipment that is designed on the best scientific and empirical theories. The range that Bigshot is describing is pretty much unnecessary, and can't even be recognized as a harmonic let alone a fundamental note.  Like it or not, that's as close to a fact as one will ever find in audio.

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