> I can't hear the difference between 128 kbps opus and FLAC.
A reasonable definition of transparency for high bitrate compressed audio is "Can the worst files be distinguished by a listener trained in what artifacts sound like". Maybe also add in having to use a high discrimination listening setup, including not running excessively loud (increases masking).
If that's not the test you're doing, it's unsurprising. At moderately high bitrates no one can reliably distinguish them on arbitrary samples: most inputs are easy.
If you test on known-difficult "killer samples" you'll probably easily distinguish them, even without first being shown what to look for, and certainly after.
During the development of Opus I created many 'trained listeners' and selected many killer samples, and I don't recall* ever encountering a tin ear that couldn't be taught to ABX any high rate samples, though some people are obviously much better at it.
I'm not sure I'd recommend it though: learning to identify artifacts has a frequent side effect of making low rate audio like the HE-aac used in SirusXM absolutely intolerable. I'm bothered by it even when I hear cars driving by using it. :)
[*] My memory for such things sucks, so I could be wrong-- but my point that it's not expected remains.
And that's fine! I've got a flatmate who loves 320kpbs MP3s on studio monitors, I've got musician friends who swear by CD-audio and Sennheiser HD200s, and others who love how vinyl uniquely degrades over time on big speakers.
The takeaway from these sorts of posts, at least in my opinion, should be two-fold:
* Understand the physical limits of human senses and perceptions to help inoculate yourself against outright scams and grifts
* Liberate you from the "tech grind" and allow you to enjoy what you like, how you like it.
The thing I didn't understand with higher quality music files is that it's not like the entire song is different and better when you go from 64 to 128 kbps opus, it's just these super minor details that get changed. It was enlightening doing an abx test, but I still use flacs because it's nice not worrying about the quality mattering.
> Understand the physical limits of human senses and perceptions to help inoculate yourself against outright scams and grifts
Also understand that while there is an upper limit, we are all different within that. I can hear the difference between 128Kbps and FLAC, at least for some content, but not 256Kbps, maybe not 192. For some content (spoken word etc.), 64Kbps, sometimes less, is perfectly acceptable (to me). There was a time I could hear the difference between some encoders, but that was decades ago and anything in active use is pretty damn good (and my ears are not what they used to be) unless you really crank the bitrate down or tweak other options daftly.
I’ve not tried encoding my own MP3s in at least a decade, but when I was doing so, 128 kbps was instantly distinguishable to me on anything with cymbals, especially hi-hat: it loses that shimmery sound. At 192 kbps I could tell if I really, really tried, but it was so minute I didn’t really care. I was never able to reliably tell the difference between 256 and 320 kbps rips.
> I can't hear the difference between 128 kbps opus and FLAC.
A reasonable definition of transparency for high bitrate compressed audio is "Can the worst files be distinguished by a listener trained in what artifacts sound like". Maybe also add in having to use a high discrimination listening setup, including not running excessively loud (increases masking).
If that's not the test you're doing, it's unsurprising. At moderately high bitrates no one can reliably distinguish them on arbitrary samples: most inputs are easy.
If you test on known-difficult "killer samples" you'll probably easily distinguish them, even without first being shown what to look for, and certainly after.
During the development of Opus I created many 'trained listeners' and selected many killer samples, and I don't recall* ever encountering a tin ear that couldn't be taught to ABX any high rate samples, though some people are obviously much better at it.
I'm not sure I'd recommend it though: learning to identify artifacts has a frequent side effect of making low rate audio like the HE-aac used in SirusXM absolutely intolerable. I'm bothered by it even when I hear cars driving by using it. :)
[*] My memory for such things sucks, so I could be wrong-- but my point that it's not expected remains.
I did the ABX test extension in foobar2000 with Octopus's Garden. It was on nice headphones.
You're right it's just minor details.
And that's fine! I've got a flatmate who loves 320kpbs MP3s on studio monitors, I've got musician friends who swear by CD-audio and Sennheiser HD200s, and others who love how vinyl uniquely degrades over time on big speakers.
The takeaway from these sorts of posts, at least in my opinion, should be two-fold:
* Understand the physical limits of human senses and perceptions to help inoculate yourself against outright scams and grifts
* Liberate you from the "tech grind" and allow you to enjoy what you like, how you like it.
The thing I didn't understand with higher quality music files is that it's not like the entire song is different and better when you go from 64 to 128 kbps opus, it's just these super minor details that get changed. It was enlightening doing an abx test, but I still use flacs because it's nice not worrying about the quality mattering.
> Understand the physical limits of human senses and perceptions to help inoculate yourself against outright scams and grifts
Also understand that while there is an upper limit, we are all different within that. I can hear the difference between 128Kbps and FLAC, at least for some content, but not 256Kbps, maybe not 192. For some content (spoken word etc.), 64Kbps, sometimes less, is perfectly acceptable (to me). There was a time I could hear the difference between some encoders, but that was decades ago and anything in active use is pretty damn good (and my ears are not what they used to be) unless you really crank the bitrate down or tweak other options daftly.
I’ve not tried encoding my own MP3s in at least a decade, but when I was doing so, 128 kbps was instantly distinguishable to me on anything with cymbals, especially hi-hat: it loses that shimmery sound. At 192 kbps I could tell if I really, really tried, but it was so minute I didn’t really care. I was never able to reliably tell the difference between 256 and 320 kbps rips.
> I can hear the difference between 128Kbps and FLAC
You've established this with double bind testing, correct?
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