Perhaps you’ve noticed a recent uptick in music streaming services advertising “lossless audio.” As technology improves, more of these services have been able to improve their song libraries by supporting higher-resolution formats. That’s good news for the millions of music lovers who have adopted streaming as their go-to means of listening to music. However, to take full advantage of this shift, it helps to know what lossless audio actually is and whether your preferred streaming service actually supports it.

Lossless audio can be a confusing term, especially since so many streaming services are now beginning to offer tiers or packages that distinguish between “lossy” and “lossless” file formats. The idea is that lossless audio means higher quality, and this is generally true — though it helps to understand the what and the why before you rush to upgrade your audio setup.

Let’s define lossless audio and walk through what you need to listen to it at home.

What is lossless audio?

The term “lossless audio” describes compressed audio files that retain all of the audio information from the original recording. This is in contrast to “lossy audio,” which describes compressed file formats that delete some of the original audio information.

It’s important to note that both lossless and lossy audio files go through a process called compression, which involves shrinking the size of the file so that it takes up less storage space. Compression certainly has its benefits — it makes files easier to store locally and requires less internet bandwidth for uninterrupted streaming. But the compression process can result in the loss of some audio data, which some people may be able to detect as inferior quality.

What’s lost in a “lossy” audio file?

To understand what’s lost in a “lossy” file, it helps to know how sample rate and bit depth work. Together, these two measurements tell us something about a digital audio file’s sound quality.

• Sample rate: Digital audio files take a certain number of snapshots of a recording’s original soundwave, then stitch these together to form a reproduction of the original recording. The more snapshots taken, the higher the sample rate — and the higher the sample rate, the higher the quality.
• Bit depth: It also helps if each of these snapshots is capturing the entire soundwave, or just a portion of it. Digital recordings that capture more of the range between loud and quiet are said to have a higher bit depth, which also results in higher quality.

Combine a high-enough sample rate with a high-enough bit depth, and you get a compressed digital reproduction that’s basically indistinguishable from the original recording. In other words, you get “lossless audio.” But if the compression process favours a lower sample rate and bit depth in favour of a smaller file size, it may result in a “lossy” audio file.

Where can I access lossless audio?

Lossless audio is already available on a number of popular streaming services. Apple Music, for example, touts a proprietary lossless audio compression technology called Apple Lossless Audio Codec (ALAC). Amazon Music subscribers can also find lossless audio at two tiers of quality: High Definition and Ultra High Definition.

Both Apple Music and Amazon Music define “lossless audio” as starting at CD quality (or 16-bit). You may not think of CDs as the most cutting-edge technology, but standard CD quality audio was originally determined to be high enough that the human ear could not detect a difference between CD quality and the original recording. Recent studies show that some people may be able to hear beyond that with training, but if you’re looking for the shortest path to lossless audio, consider dusting off your old CD collection.

Is lossless audio better than regular audio?

The short answer is yes. Lossless audio offers a better and richer sound experience than lossy audio alternatives, which have become the “regular audio” standard thanks to the rise of streaming services.

But for the best listening experience, nothing beats a quality speaker. The difference between an Apple ALAC file and an Amazon Ultra High Definition file is relatively small, but your cell phone’s built-in speaker won’t do either of them justice. To really benefit from lossless audio technology, you’ll need equipment that can handle it.

What do I need to listen to lossless audio?

Lossless audio is much more attainable than it used to be, and a quality speaker or headphones should be all you need. Since lossless audio covers a wider range of frequencies than lossy audio, your speakers should be able to handle frequencies within the full range of human hearing (generally 20 Hz to 20 kHz).

You can even listen to lossless audio wirelessly with Sonos products. Our wireless speakers and soundbars all support lossless audio playback.

Can you play lossless over Bluetooth?

Yes, though this hasn’t always been the case. It’s exceedingly difficult to transmit audio data over Bluetooth without at least a bit of compression, so most Bluetooth speakers and earbuds don’t support lossless audio. Sonos Ace is among a relatively small class of headphones that can achieve lossless audio with a Bluetooth connection. For other headphones and speakers like Sonos Move 2, Bluetooth can still deliver impressively clear sound, though you’ll want to connect via WiFi for the best audio experience.

Lossless vs. other types of audio

You may have heard of other terms used to describe high-quality audio, but how do terms like “HiFi” and “spatial audio” relate to lossless? Let’s take a look.

Lossless vs. HiFi audio

Because the term “lossless” relates specifically to digital file compression, lossless audio typically describes audio formats that don’t lose any of the original signal in the process of compression. You’d describe an audio coding format such as Apple Lossless Audio Codec (ALAC) as “lossless,” but you wouldn’t use the term to describe, say, a set of premium speakers.

High-fidelity audio, or HiFi for short, usually describes a full system or setup that’s capable of reproducing audio from the original recording with a high degree of exactness. So, a HiFi setup would include speakers, an amplifier, and other physical audio components.

Lossless vs. hi-resolution audio

Hi-resolution audio, or hi-res audio for short, is related to lossless audio but is not exactly the same.

Above, we mentioned that compression can result in a lossy audio file or a lossless audio file. But an audio file does not need to be compressed at all. Uncompressed formats can support even higher bit depths and sampling rates than some lossless audio formats.

The term “hi-res audio” tends to bucket together lossless and uncompressed formats that achieve a certain sound quality — typically superior to that of a CD.

Lossless vs. spatial audio

Spatial audio describes an immersive, three-dimensional listening experience that makes you feel as if sounds are coming from all directions. Spatial audio technologies like Dolby Atmos add the sense of height to audio playback that more closely reflects how you hear sound in real life. This can be an impressive feature of a home cinema system, but it’s not about compression.

Experience lossless audio with Sonos

Lossless audio has become a buzzy topic in recent years, as people have realised that even the best sound systems can’t compensate for lossy streaming quality. The good news is that more and more streaming services are debuting their own lossless formats, and we may be fast-approaching a day when lossless audio compression becomes the norm. To prepare yourself for that eventuality, upgrade to a Sonos speaker or soundbar that can support lossless audio quality over WiFi.