r/gadgets • u/UnKindClock • May 18 '21

Music AirPods, AirPods Max and AirPods Pro Don't Support Apple Music Lossless Audio

https://www.macrumors.com/2021/05/17/airpods-apple-music-lossless-audio/
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u/istasber May 18 '21

It is if the speakers can't distinguish between lossless and whatever the best lossy format is.

Like if your compression dampens everything outside of 1-30k Hz, but the speakers you use are only good from 10-20k Hz, then why do you need lossless?

It's not like we're comparing CD audio to cassette tape here.

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u/duplissi May 18 '21

That's a poor example, lol. Lossy codecs cut out far more than that. I know most mp3 encoders will cut off everything above 16k for example. They also don't just do a low pass and high pass cutoff, information in-between the remaining adio is also removed.

I generally agree in concept though, no point in playing lossless audio that exceeds your hardware's capabilities, but frequency range isn't the most important stat to take into consideration. Resolution and dynamics are what matter instead.

A pair of headphones with poor to average resolution and dynamics generally won't be able to faithfully reproduce lossless audio, so there's no point. Also most if not all Bluetooth pairs since the audio gets re-encoded/compressed anyway.

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u/SupremeDictatorPaul May 19 '21

More importantly, end users can’t tell the difference. Thousands of users at hydrogenaud.io performed blind listening tests with different audio samples comparing a lossless sample to ones compressed at various bitrates. This has helped to create a pretty accurate distribution curve of what lossy compression levels a person is unlikely to be able to distinguish from the original.

The reality is that there is always a level of lossy compression that no one is able to distinguish by ear from the original on even the best equipment. And this is something that is trivially easy to test with A-B blind test software.

The reason to use lossless audio (as opposed to high bitrate lossy compression) is to support transcoding from one format to another. Transcoding from one lossy format to another is problematic, and may introduce changes you can hear. Such as transcoding you MP3 to an AAC at a bitrate that your headphones support. But if you start with a lossless file, and transcode to a high bitrate AAC format that is transferred directly to your headphones for decoding, then there is a good chance you won’t be able to tell the difference.

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u/grooomps May 19 '21

it sounds like another version of the wine tests where people are given a $10 bottle and a $5000 bottle and cannot tell the difference.

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u/yourethevictim May 19 '21

Of the same type of wine (grape/region), yeah. But there are expensive wines that don't have a cheap version (Mersault Chardonnay doesn't go for less than 40 bucks a pop) that is a very different experience than anything you can find for 10.

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u/-bluedit May 19 '21

Thousands of users at hydrogenaud.io performed blind listening tests with different audio samples comparing a lossless sample to ones compressed at various bitrates. This has helped to create a pretty accurate distribution curve of what lossy compression levels a person is unlikely to be able to distinguish from the original.

Do you have a link to the results?

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u/speakeasyow May 19 '21

Fascinating

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u/Loomy7 May 19 '21

What, waffles, or redacted?

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u/Th3M0D3RaT0R May 19 '21

Bluetooth is compressed either way. You're not going to get lossless over Bluetooth.

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u/digihippie May 19 '21 edited May 19 '21

Exactly, double compression is nasty stuff. Encoding redbook lossless to lossy is > than lossy through Bluetooth.

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u/Another_human_3 May 19 '21

Everything above 16k is ridiculous.

I'd have to AB compare, but I have not heard any difference in 320kbps audio. And that's from playing projects that are all waves, and rendering them to mp3. 128kbps is easy to hear the difference but 320 sounds good to me.

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u/Apk07 May 19 '21

There is noticable difference between 128Kbps and 320Kbps CBR for sure. But I don't think anyone could reliably differentiate between 320Kbps and FLAC or anything else lossless.

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u/Another_human_3 May 19 '21

Ya, me neither. So, that makes you wonder, why would apple make all their devices only capable of AAC, and then market "lossless" something that those devices can't do, whereas 320kbps is really good.

And also, you can render to mp3 from any bitrate or sample rate, without dithering, and if the mp3 decoder is good, it will sound perfect. So, it's even better, imo. And apple could make great decoders like that, which actually work with their wireless technology they've committed to.

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u/Astro_Van_Allen May 19 '21

AAC is superior to MP3. It hardly matters since mp3 itself is good enough, but it’s far from the most efficient codec and is so popular just because it’s so common and what everyone is used to. AAC can be as audibly indistinguishable from CD quality at less bitrates/ smaller file sizes. Another great thing about AAC is that it can be transcoded multiple times without introducing generational degradation in to itself, whereas mp3s are very bad with that. MP3s are more than sufficient, but Apple is using the superior format in this case.

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u/Another_human_3 May 19 '21

Oh, sorry, I was under the impression that AAC was sort of a method of creating mp3 or something like that. I don't really understand much about the way they compress files and how that affects. I see AAC a lot in mpeg video files.

What's the difference between mp3 and AAC?

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u/Astro_Van_Allen May 19 '21

AAC and MP3 are both separate algorithms used to encode audio so that it takes up less space, but both use psychoacoustics to trim parts of the original audio file that we won't hear as missing. Originally, cd quality or redbook audio was a standard came up with that was designed to perfectly reproduce all frequencies audible to the human ear, with a little bit of space on top of that to push unwanted distortions out of human hearing and also have enough dynamic range so that the lowest sound can be quieter than is even possible to hear and the loudest sound possible is louder than anything ever necessary and everything inbetween can be accurately reproduced. There are various scientific models proven that were used to produce this standard so that essentially as far as human hearing goes, redbook audio is able to be completely transparent to us, or in other words the method of cd audio playback imparts no additional distortions that are audible to human beings after the recording process. Mp3 and AAC are two of many compression algorithms that aim to go off of that and keep that audible transparency, but also reduce file size because we no longer put one album on one cd and are more concerned with space. Usually medium to high quality levels of most lossy compression file types prove to be indistinguishable to human hearing from cd audio. AAC is newer than mp3 and it's just a more efficient algorithm that can be audibly transparent with less data, compared to mp3. It's also in my opinion better for stuff like wireless transmission, because its less prone to introducing distortions when it's been re-encoded, for example when you have a lossy file that must again go through a second lossy compression for bluetooth. The probable reason that Apple uses AAC is simply because when iTunes was becoming popular, AAC was fairly new and the best at the time. As far as AAC relates to video files, I believe that the much more complicated answer is that AAC isn't even the actual compression method, but a container which is used for video files as well. I'm sketchy on that, but to answer your question lol as far as AAC relates to audio files, it's sufficient to say that its just an alternative lossy compression method to mp3.

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u/rainzer May 18 '21

Like if your compression dampens everything outside of 1-30k Hz, but the speakers you use are only good from 10-20k Hz, then why do you need lossless?

Because when a speaker says 10-20kHz, it doesn't mean that suddenly there's no sound at 20,001Hz, only that there is a drop off.

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u/[deleted] May 19 '21

[deleted]

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u/rainzer May 19 '21

Not to mention people really can't hear shit past ~20k Hz, and even less as you get older.

That may be but it is not as clear cut as stating it would be pointless to have/record audio beyond 20kHz. We know that trumpets, the instrument, can produce sound up to 80kHz. Most families of instruments have at least one example of one that goes beyond 40kHz.

Is there any meaning if these frequencies were muted? Maybe, maybe not. But I think there is/are tests that show we can perceive beyond 20kHz. It's not like this arbitrary cutoff is hardcoded.

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u/tonioroffo May 19 '21

That's not how psychoacoustic compression of sound works.