What is lossless audio? – Android Authority

Chances are, if you listen to music you want it to sound good. And for the best quality various how-tos and internet tips recommend lossless audio. But what is lossless audio and where can you get tracks that feature it? And what’s with HiFi audio, anyway?

Fear not, we’ll guide you through these sometimes messy terms and help you decide if lossless audio is worth it for you and where to find tracks that take full advantage of it.

What does lossless mean?

The Beyerdynamic M 70 Pro X microphone.

To understand lossless audio, we’ll have to start where most things related to audio start: the human ear. Most people, barring exceptionally rare edge cases, can only hear sounds within a frequency range from 20Hz-20kHz. This can vary, and as you age it drops, but overall that’s where everything you’ll ever hear — whether from headphones or out on the street — lies. But just because you can’t hear anything else doesn’t mean other frequencies don’t exist. For example, consider a dog whistle; you can’t hear it, but your dog can. When recording music and converting it to digital, every possible frequency that a microphone can detect gets saved, even if you’ll never hear it.

Because this process preserves every last piece of data, it’s called lossless.

Lossless audio often leads to very large files. In contrast, “lossy” audio throws out any data related to frequencies you cannot hear, which makes file sizes smaller. Very lossy audio, by extension, throws out data you can hear, too.

But there’s a bit more to the story than that, because both lossy and lossless audio can also involve audio compression. There are uncompressed lossless audio files including WAV on Windows and AIFF on macOS. However, as mentioned, saving large amounts of sound data takes up huge amount of space. As a result, engineers have developed various ways to make audio files smaller. Throwing out frequencies, which is what lossy formats such as MP3 do, can lead to quite small files. Compression may also introduce other issues which comprise sound quality. Sometimes, trying to compress a sound file too much can lead to something called compression artifacts. These are unpleasant sounds the compression process itself creates and not found in the original recording. Furthermore, certain types of music might experience “pre-echo,” or hearing a sound slightly before it it actually occurs in a track due to the way compression works.

In order to preserve all the data present in a file, keep its original quality, and not introduce any artifacts, smaller lossless audio formats, such as FLAC, use other tricks to accomplish compression. Still, these files will never be as small as lossy formats. But what you lose in hard drive space you gain in sound quality and preserving the integrity of the original recording.

What about bitrates and HiFi?

Tchriusop-down view of Sony WH-1000XM5 beside the Bose QuietComfort 45 on a metal surface

Chris Thomas / Android Authority

Something that often gets tangled into discussions of lossless audio is bitrate. This is a rather complicated topic, but to simplify it here, the “debate” usually boils down to 16-bit versus 24-bit files. Bitrate refers to how often a digital representation “samples” an analog audio signal. Think of it like taking the temperature of a pot of water heating on a stove. If you dip a thermometer into the water and write down the value, you’ll eventually be able to plot how it increases over time. The more times you do this per second, the higher the bitrate.

A standard audio CD uses 16-bit audio and gets a rage of 44.1kHz — hence the name “CD-quality sound.” CD-quality is also called “HD” sound. It’s already more than double of the range of human hearing. By extension, 24-bit audio can achieve 96kHz and above. Therefore, it often gets labeled “Ultra HD.” So it must be better, right? Plus, streaming services often lump everything into “lossless HiFi streaming” to make it even more confusing.

Whether you, or anyone else, will hear a difference between 16-bit and 24-bit audio is questionable.

Not so fast. Besides the fact that the human ear cannot perceive sounds that high in frequency, we also know that because of some complicated math known as the Nyquist-Shannon sampling theorem, 16-bit audio at 44.1kHz is more than enough to perfectly reproduce any signal within the bounded frequency range of human hearing. The boosters behind 24-bit audio claim that because more samples happen per second, the resulting curves are “smoother” or less “jagged” but that doesn’t result in an any audible difference in practice. Why? Well, for one thing, the curves produced are still just as smooth. You can think of it like over-explaining a topic: you only need a certain amount of detail to convey an idea, and eventually it’s just diminishing returns.

Overall, lossless audio is any file format that preserves everything a microphone has recorded and is at least 16-bit at 44.1kHz. Higher bitrates are certainly possible, but you likely won’t notice a difference. Still, as we’ll see in a bit, both higher bitrates and lossless streaming tend to be available via HiFi streaming services or tiers anyway.

What streaming services support lossless audio?

More and more streaming services now have lossless audio available. Usually, these you’ll find this option in paid “hi-res,” “HiFi”, “HD” or “Ultra HD” tiers. Ripping the files off a CD will also give you lossless files to enjoy locally. But that’s not the most convenient option, so here are some streaming services that offer lossless audio. Keep in mind that lossless files are big, and you’ll eat up lots of data streaming them. If you’re on a plan with a data cap, it might be best to enjoy them over Wi-Fi instead. Plus, while many phones these days can handle playing back lossless files, you might need external adapters for the very high bitrate options.

Apple Music

Apple Music Radio section

Edgar Cervantes / Android Authority

Apple Music offers two tiers of lossless audio. CD-quality is available with your subscription. You can enable it in Settings > Music > Audio Quality on your iOS device. There are also “hi-res” 24-bit lossless tracks available. However, these require you to use an external digital to analog converter.

Amazon Music HD

On Amazon Music, signing up for an Unlimited subscription gives you access to lossless HD (16-bit) and Ultra HD (24-bit) tracks at no extra cost. Amazon Music will indicate if a track is HD or Ultra HD content with a small icon in the player app.

Deezer HiFi

Deezer Android app

Signing up for Deezer gives you access to Deezer HiFi. You can enjoy lossless CD-quality tracks without paying extra. There’s no “Ultra HD” or “hi-res” subscription level, but as mentioned this isn’t all too important.

Tidal HiFi

Tidal Android app

Tidal breaks down its lossless streaming options into two tiers. HiFi is $9.99 USD a month and provides access to CD-quality tracks. HiFi Plus is $19.99 and goes up to 24-bit tracks, but you might opt for this tier because it also includes spatial audio support for Dolby Atmos and Sony 360 Reality Audio.

Qobuz

Qobuz screenshot 2020

Joe Hindy / Android Authority

Qobuz offers a Studio subscription at $10.83 USD per month and Sublime at $15.00 USD a month. Both have up to 24-bit, 192kHz lossless streaming. Sublime also includes a discount of up to 60% on every hi-res download.

What about Spotify HiFi?

jbl connect spotify

Ryan Haines / Android Authority

Spotify announced a lossless streaming service known as Spotify HiFi that was supposed to debut in 2021, but so far it has yet to make an appearance. When (if?) it launches, it will likely feature CD-quality audio available for streaming.

Can you stream lossless audio over Bluetooth?

There’s one limiting factor when it comes to enjoying lossless audio you might not have considered: Bluetooth audio. Long story short, every currently widely-used Bluetooth codec compresses audio at least a little at some point. There are complicated technical reasons for this, but suffice to say there’s a tradeoff between bandwidth, connection stability, and audio quality. There basically isn’t enough room in a Bluetooth signal to cram in the data for a lossless audio stream.

To circumvent the bandwidth issue, Bluetooth codecs use various tricks to keep a connection stable. Certain codecs are better at this than others. For instance, the widely-available SBC codec doesn’t keep quality all that high so not much data is sent, but the connection is pretty stable. Higher quality codecs, such as aptX and aptX HD use more advanced algorithms. Certain codecs like aptX Adaptive and LDAC can actually vary their bitrate depending on the content and needs of the connection. In fact, LDAC reaches nearly CD-quality audio overall. It’s not a perfect match, but only really picky listeners would be likely to notice. There’s also aptX Lossless, which is set to debut on devices sometime this year.

Long story short, if you use Bluetooth headphones to listen to lossless audio tracks, you’ll lose some quality. It’s better than starting with lossy audio tracks, but it won’t be the full experience, if you’re concerned about that. In order to take full advantage of what lossless audio offers, it’s best to stick with wired listening options.

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