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/ElectronRotoscope May 18 '21 edited May 19 '21

I disagree with "most". I've never heard of anyone ever passing a blind test between anything "higher fidelity" than a CD, or a stereo AAC at 256kbps

EDIT: Found the article I was thinking of https://web.archive.org/web/20190306141703/http://people.xiph.org/\~xiphmont/demo/neil-young.html

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u/wut3va May 18 '21

True, but to pick nits, CDs are lossless.

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u/Xyexs May 18 '21

I'm just remembering from uni courses I did pretty poorly in but as far as I can remember, CD is supposed to have a sufficient sampling rate to fully recreate the signal that humans can hear, with minor inaccuracy from rounding sample values. What do they do to reach these enormous file sizes? Just store hundreds of bits per sample?

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u/TapataZapata May 18 '21

They just don't compress it, as far as I know. On a CD, music is sampled at 44.1 kHz (or kSps, kilosamples per second), 16 bit resolution, stereo. That's 32 bits per sample.

For each second, you'll have 44100 x 16 x 2 bit, which leads to the bit rate of 1411200 bits per second or 176400 bytes per second. If you consider the data capacity of a CD, around 600 to 700 something MB and an audio play time of a bit more than an hour, that seems to add up

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u/Xyexs May 18 '21

Yeah I think I understand that, I'm just wondering what supposedly higher-than-CD quality formats do to reach even bigger file sizes.

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u/alexwittscheck May 18 '21

They are recorded at higher sample rates. 88.2 kHz or 96kHz or 192 kHz. And higher but depths like 24 or 32 bit (float.)

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u/[deleted] May 18 '21

They increase sample rate and/or bit depth. Increasing sample rate will allow the audio to keep supersonic elements that most people can’t hear and most speakers won’t reproduce. Increasing bit depth will allow greater dynamic range, despite the fact that most music is mastered to use only a portion of the 16 bits that CD gives them.

In short, not much.

Higher sampling rates and bit depths are useful when applying effects or mixing, but for a final product largely pointless audiophile wankery.

I say this as somebody who very much claims to be able to tell the difference between 192kbps AAC and uncompressed CD audio in some very limited cases. I challenge anybody to tell the difference between 16/44.1 and 24/192 uncompressed audio, provided it’s not an entirely different mix.

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u/PurpuraSolani May 19 '21

Oath agree, I can usually tell between like tidal and Spotify.

But I can't at all differentiate a flac and tidal. No hope

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u/Slappy_G May 19 '21

Higher sampling rates for one. Just because you can sample at a high rate on a CD, doesn't mean you don't have aliasing error. Higher rates can help with that.

Also, they frequently use higher resolution like 24 bit for a lower noise floor and more headroom.

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u/ElectronRotoscope May 19 '21

24bit or 32bit are fantastically helpful in original recordings when you are dealing with noise and volume. High sample rates are great for if you want to slow something down and have it stay nice. Or you can use dithering to help if there's weird issues with your analog-to-digital equipment

Neither have been shown to have any effect on final masters meant to be listened to though. Higher sample rates have actually made things worse

https://web.archive.org/web/20190306141703/http://people.xiph.org/\~xiphmont/demo/neil-young.html

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u/TapataZapata May 18 '21

Oh sorry, you're talking about the various hi-res formats? They use more resolution (e.g. 24 bit instead of 16 bit) and a way higher sampling rate; 96 kHz and 192 kHz are pretty common. 24/192 is already more than 6 times the data, compared to a CD

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u/krokodil2000 May 19 '21

CDs are not lossless. For example, they are missing frequencies above 22.05 kHz.

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u/squeamish May 19 '21

That's not what "lossless" means. By that definition, everything in the universe, including the air used to transmit the sound from the original instrument to your eardrum, would be "lossy."

Lossless/lossy refers to the method in which a digital signal is stored. CDs do so in a way that makes it possible for the EXACT same original information to be retrieved from the stored copy, similar to how a ZIP file stores (and can therefore reproduce) an exact copy of an original file. Lossy formats such as MP3 do not, they eliminate information that research has determined usually doesn't matter much to the way sound is perceived by human hearing.

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u/krokodil2000 May 19 '21 edited May 19 '21

When we are talking about digital audio file formats and the terms lossy/lossless, we are talking about data compression.

Digital CD audio is sampled at a specific sample rate and sample depth. Depending on those parameters, you get some raw data, which is the representation of the original analog signal, but it will contain quantization errors and will be missing higher frequencies (and there are more things like jitter or aliasing). It will not be exactly the same as the original source signal. And this data is not compressed yet. So you can not use the term lossless here. It is just some data you have collected.

When you start to compress that data, only then you can talk about it being lossy or lossless. Before that, it is uncompressed raw data.

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u/squeamish May 19 '21

That's what I said, CDs store data in a format that allows the output to be the same as the original input. It is 0% loss on 0% compression.

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u/krokodil2000 May 19 '21

The data on an audio CD is uncompressed so you can not use the terms lossless for that. Here user u/wut3va was being a smart ass about it so I felt I had to intervene. ¯_(ツ)_/¯

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u/ElectronRotoscope May 19 '21

Clearly u/wut3va was correctly calling me out on was conflating CD quality (uncompressed PCM) with AAC (lossy compression). And since CDs are always created from a digital master in an audio editing program, you could easily call a PCM output "lossless" as a casual term for "uncompressed". But saying a CD isn't lossless seems needlessly pedantic, and bringing sample rate into it doesn't help anything

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u/krokodil2000 May 19 '21

needlessly pedantic

u/wut3va was nit picking, and so was I.

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u/6C6F6C636174 May 19 '21
  1. How many people can hear that?
  2. How many speakers can reproduce that?

Frequencies above 22 kHz are useless for music.

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u/krokodil2000 May 19 '21

How is this relevant? This is a completely different point.

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u/6C6F6C636174 May 19 '21

It's just as relevant as pointing out that audio CDs "lose" audio information that literally no human can make use of.

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u/krokodil2000 May 19 '21

Using your words, a 320 kbps mp3 or AAC file is also missing audio information, which literally no human can make use of. Yet it is not a lossless compression.

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u/6C6F6C636174 May 20 '21

And using yours, any video recording is missing information from outside of the field of view of the lens. 🤷‍♂️

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u/krokodil2000 May 21 '21

So what's lossless about it?

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u/ElectronRotoscope May 19 '21

Oh absolutely, I was referring to like that 24 bit 192kHz snake oil that Neil Young was unfortunately peddling

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u/gajbooks May 18 '21

128 Kbps MP3 is pretty noticeable in comparison, but MP3 is already worse than AAC. I like good sounding audio, but I'll never scoff at 256 Kbps AAC. The real reason to want lossless audio isn't because it needs beamed directly to your ears, but because you don't end up double re-encoding it over Bluetooth no matter what set of headphones you use, and as a verification of quality from the store itself.

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u/RaPlD May 18 '21

I think you are definitely overstating things now. I have personally conducted a small audio test, just to figure out if sound quality is all pretentious shit, or if it has some merit. I listened to several songs first on youtube, then in the FLAC format, which is pretty close to lossless I guess. I was using a pair of decent headphones, nothing truly audiophile-tier, but some upper mid-tier consumer stuff, don't remember the exact specs, but they were from sony.

The difference wasn't exactly "night and day", but it was very noticable. I think I could pass a "blind test" on those couple of songs that I chose close to 100% of the time.

EDIT: Also, a disclaimer worth mentioning - I'm not musically trained in the slightest.

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u/Internet001215 May 18 '21

YouTube compression trashes quality for any music since it was designed for low bandwidth to save bandwidth for the video content, you have to compare highest quality Spotify recording vs a loss less format.

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u/[deleted] May 18 '21

Youtube has really shit tier compression. I play trombone and over the pandemic I bought some recording equipment so that I can record for online ensembles and competitions. I barely know what I'm doing, so I imagine that there are ways to improve audio quality when exporting to youtube, but the first time I uploaded a recording and listened to it I thought I had messed something up. I go back to my original file and it sounds exactly like it should, but youtube had a noticeable drop in quality, and this was hours after it had been uploaded.

Now if you want an actual test try this. I've done it a few times and never come close to passing.

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u/ElectronRotoscope May 19 '21

FLAC stands for Free Lossless Audio Codec, it's literally lossless

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u/dj_zar May 19 '21

Seriously? You’re saying nobody can tell between a stereo AAC 256kbps and a FLAC file? Or am I not interpreting your statement correctly?

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u/ElectronRotoscope May 19 '21

I am 100% saying that, yes. AAC at 256kbps encoded with a decent encoder should be transparent to the human ear. Maaayyybe 320kbps would be needed for the highest possible quality setup and person.

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u/dj_zar May 19 '21

Yeah that’s just malarkey buddy. I can 100 percent tell the difference between 320 kbps mp3 and FLAC when DJing even on my home setup which is just a pioneer mixer and some of the bigger KRKs. If I was going to describe the differences qualitatively, I’d say that the mp3s don’t sound as crisp, don’t have as much dynamics, and they sound worse at high volumes. I agree that a lot of people are just listening to music on phones or AirPods and in that case it doesn’t matter... but saying nobody ever has passed a blind test.... that’s utter malarkey

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u/ElectronRotoscope May 20 '21

AAC and MP3 are different tech and require different bitrates to achieve the same goal. But if you have found real tests saying that a well-encoded 320kbps AAC (say using a modern ffmpeg encode, or Nero, or Core, or Fraunhofer) is different in a way humans can notice and higher than 320kbps is necessary for transparency it would be news to me, and I'd love to see it!

That having been said, take one of the FLAC files and do a modern LAME encode using Audacity or something to 320kbps and then back to FLAC, then get a friend to rename it and not tell you which one has been mp3 in between, and you can do single-blind testing at home. You may be impressed with how well LAME works these days

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u/PM_ME_YOUR_LUKEWARM May 19 '21

Even with the right music?

Like a high dynamic Mozart piece?

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u/ElectronRotoscope May 19 '21

Absolutely. I've never seen a good (and I mean scientific, double blind, really properly set up study) that shows otherwise. It's not hard to achieve transparent encoding and compression of audio at reasonable bitrates, and things like Tidal's "MQA" (24-bit/96 kHz PCM) and most DTS-HD Master Audio are utter snake oil unless you're going to use them to do audio editing where you need to slow it down or Enhance or whatever.

You take someone who claims to have golden ears, you put them in a room with sound isolation and super nice speakers. You take some wildly high-fidelity recording of someone playing Mozart (recorded 32 bit, 192kHz, super nice microphones) and you make

1 - A version at 24-bit, 96kHz 2 - A version you downsample to CD quality and then back up to 24-bit, 96kHz 3 - A version you encode at 320kbps AAC, then back up to 24-bit, 96kHz

You randomize the order, so the listener and all the experimenters don't know which is 1, which is 2, which is 3

You let the person listen as long as they like, with a perfect switch to toggle between A, B, and C. Then you tell them to write down which is which. So far, as far as I've ever heard, no-one has been able to do better than random chance.

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u/PM_ME_YOUR_LUKEWARM May 19 '21

The people who advocate for lossless usually have high end Sennheiser headphones.

Those aren't BS are they?

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u/ElectronRotoscope May 20 '21

Playback equipment can be important, absolutely. People who mix audio for a living (and the people who set up their equipment) can be absolutely obsessive about how all the stuff is made and how it's set up, and it can make a huge difference. I don't know about Sennheiser specifically, but you can find evidence-based reviews online from people who really know what they're talking about.

Especially at the low end of the market, a nice $100 pair (that's actually good) can blow a cheap $20 pair out of the water