A woman lying on the grass wearing over-ear headphones
A woman lying on the grass wearing over-ear headphones

A beginner's guide to Apple Lossless Audio

By Trent

Apple has just announced that it will be making its entire Apple Music catalog available in lossless audio, joining the likes of Amazon Music HD and Tidal in offering CD-quality streaming. What's more, this upgrade comes at no increase in subscription cost. 

A comparison table of various popular lossless streaming services

But while the announcement was definitely music to the ears of audiophiles, the average Apple Music user might not understand exactly what lossless audio means for them, or how to take advantage of it. In this article, we take a deep dive into the world of lossless audio, related concepts and technologies, and what you will need to enjoy Apple's new Lossless Audio service.

(Editor's note: Throughout this article, we will differentiate between the lower-case 'lossless audio' as the generic concept, and the title case “Lossless Audio” as the branded Apple Music format)

Basics of digital audio

Digital audio representation primarily involves two concepts, which are essential to understand when it comes to dealing with lossless audio: Bit depth and sampling rate.

Sampling rate

While digital audio uses traditional analog microphones to record sound, the digitization process breaks the sound up into thousands of discrete, quantized samples. Each sample is the same size and represents a tiny piece of the original audio, similar to the way video recording uses a consistent flow of still frames to create motion. The number of samples recorded per second is known as the sampling rate and is directly related to sound quality. A sampling rate of 44.1 KHz is considered to be just above the upper limit of the human hearing range of 20 Hz to 20 KHz (doubled for stereo) and therefore the minimum for lossless audio reproduction.

To visualize this, imagine a photograph taken in different resolutions. The higher the resolution, the more pixels that can be used to reproduce the scene in the image, representing finer details and increasing clarity. These finer details can be thought of as 'high frequency' detail, limited only by smallest pixel size which can be applied to the image. Below is an example of an image of a sunset, with more detail able to be conveyed with a higher 'sampling rate' due to a smaller pixel size.

A low-resolution and high-resolution grayscale photograph of a sunset side by side to illustrate the concept of sampling rateA higher sampling rate allows for a greater depth of the sound's detail to be reproduced, similar to how a photograph made up of smaller pixels is able to provide a greater level of detail.

"A sampling rate of 44.1 KHz is considered to be just above the upper limit of the human hearing range of 20 Hz to 20 KHz (doubled for stereo) and therefore the minimum for lossless audio reproduction."

Bit depth

Complementary to sampling rate, bit depth is a measure of the breadth of information recorded per sample, and therefore how much detail each sample contains. A higher bit depth indicates wider dynamic range of the audio format, which allows it to more accurately represent the range from quiet sounds to loud sounds. The minimum typical bit depth for audio to be considered lossless is generally 16 bits.

To reuse the analogy of the photograph, a higher bit depth is equivalent to the image consisting of more varying shades of different colors. Again using our sunset image, which smoothly transitions from yellow and orange to purple—a wide palette of colors and shades will enable a much more detailed and effective reproduction than a black-and-white or grayscale photograph.

A grayscale and color photograph of a sunset to illustrate the concept of bit depthGreater bit depth allows for an greater contrast between the elements of the audio to be reproduced. This is similar to how a photograph with a wide range of colors is able to achieve greater contrast and reproduce the scene more realistically.

What is lossless audio?

When music producers, sound technicians, and mixing engineers have finished recording and processing a track, they create a 'master' of the track that represents the final mix. This master accurately represents the audio the way the artist intended, and can be a physical CD or a digital file. An audio CD contains this exact data copied from the original studio master with no loss in quality, which can also be extracted as a digital file of the same quality for playback on a computer, smartphone, or other device—This is considered to be lossless audio.

Why isn't my current digital music collection lossless?

A typical CD contains 700 megabytes (MB) of digital data, meaning that an average 3-4 minute song uses up to 35 MB of storage. Such large file sizes were a considerable challenge for prior-generation computers, music players, and internet connectivity, so scientists and engineers developed lossy compression formats such as MP3 and AAC to reduce file size while minimizing loss of sound quality. Lossy audio compression takes advantage of psychoacoustics and essentially removes portions of the audio frequency which the human ear is not able to hear well, resulting in significantly reduced file sizes for audio tracks—as small as 4 MB—with minimal quality loss to the untrained ear.

A comparison table of popular audio formats including MP3, FLAC, and CD

As the name implies, the compression process is not perfect, and the 'loss' can result in audible artifacts or a reduction in warmth and fidelity. Audio can be saved in a higher quality MP3 format or using a more advanced lossy compression codec, but the fact remains that the quality of the original CD audio will never be present in a lossy file.

"Lossy audio compression takes advantage of psychoacoustics and essentially removes portions of the audio frequency which the human ear is not able to hear well"

Bitrate

Bitrate refers to how many bits of data are used to represent each second of an audio file, and is typically applied to lossy compressed audio to indicate the size of the compressed audio data.

Bitrate is often described in terms of kilobits per second (kbps), with typical MP3 compression ranging between 64 kbps and 320 kbps. While 64 Kbps audio almost akin to AM radio quality but only takes up about half a megabyte per minute, 320 kbps audio sounds very close to CD quality to most people, but can take up nearly 5 times as much space at 2.4 megabytes per minute.

Editor's note: A kilobit is not to be confused with a kilobyte - one kilobyte is equal to 8 kilobits.

Lossless compression

"a lossless format like Apple Lossless or FLAC delivers the exact same sound that you’d hear from a CD"

Lossless compression takes advantage of predictable characteristics in audio files to compress them, allowing for as much as a 50% reduction in file size compared to audio CD tracks without losing any data. In fact, a lossless format like Apple Lossless or FLAC delivers the exact same sound that you’d hear from a CD. It is this reduction in file size which enables streaming services such as Apple Music to deliver CD quality audio without consuming excessive internet bandwidth.

What is Apple's new Lossless Audio offering?

Apple has now made its entire library available to stream in its proprietary Apple Lossless Audio Codec (ALAC) format.

How can I listen to lossless audio?

Although there is no additional subscription cost to unlock Apple's Lossless Audio streaming, there are a few minimum requirements you'll need to fulfil in order to listen to the higher-quality format.

Device

All decoding of the streaming audio files is handled by the app on your device, so there's no extra software required to enjoy the increase in quality. In most cases, Apple devices just need to be running the latest version of their respective operating systems in order to take advantage of Lossless Audio.

A table listing the minimum operating system requirements for Apple Lossless AudioThere is a minimum OS version required for Lossless Audio depending on your Apple device.

Once this is done, you will need to enable Lossless Audio in the Settings section of your operating system. Keep in mind that true lossless audio can only be achieved when listening with wired headphones/earphones or a device's built-in speakers. At the time of writing, access to Apple's Lossless Audio on Android is only available to users enrolled in their beta program.

Can I stream Lossless Audio over Bluetooth?

The short answer is, no.

Lossless audio requires a certain amount of bandwidth to transmit. While the latest Bluetooth 5.0 standard supports up to 6 mbps of bandwidth—which seems to be sufficient for lossless audio—this drops sharply as the distance between transmitter and reciever increases. In order to support reasonable ranges of up to 10 meters, Bluetooth manufacturers use lossy codecs that transmit at a variable bitrate with a current maximum of 990 kbps. Therefore, it is not possible to listen to Lossless Audio using any AirPods model. It is worth noting that even when using AirPods Max with the included cable, true lossless audio is not possible due to decoding limitations within the cable and the AirPods Max themselves.

A table showing the key features of popular Bluetooth audio formats

All current Bluetooth protocols are technically lossy, but some can still deliver very high sound quality.

"it is not possible to listen to Lossless Audio using any AirPods model."

Which Moshi products can I use for lossless streaming on my Apple devices?

In order to get the full lossless experience, you need to make sure your audio equipment is capable of handling the higher quality output. While Apple's standard EarPods do support lossless audio output, if you want to step up the quality or use your own cans or external speakers, you'll need an adapter with a built-in digital-to-analog converter (DAC) which translates the iPhone or iPad's digital audio signals into analog ones that can be used by speakers or drivers to reproduce sound.

For Lightning devices

  • Integra™ Lightning to 3.5 mm Headphone Jack Adapter - Converts the signal coming from your iPhone or iPad's Lightning port into analog audio via a 3.5 mm connector. Includes a 24-bit/48 kHz DAC.
  • Integra AUX to Lightning cable 4 ft. (1.2 m) - Connect your iPhone or iPad to an amplifier or set of external speakers to enjoy lossless audio output. Includes a 24-bit/48 kHz DAC.
  • Mythro LT - Earbuds with built in 24-bit/48 kHz DAC, durable aluminum housings, and Lightning connector. Ultra high-definition 8 mm drivers produce crisp sound with deep, punchy bass. Includes 3-button in-line remote.
  • Avanti LT - Premium, ergonomically designed on-ear headphones with 40 mm drivers to create a rich sound and immersive soundstage. Includes Lightning and 3.5 mm audio cables for use with iPhone, iPad, and MacBook.

For USB-C Apple devices

  • Mythro C - Earbuds with built in 24-bit/48 kHz DAC, durable aluminum housings, and USB-C connector. Ultra high-definition 8 mm drivers produce crisp sound with deep, punchy bass. Includes 4-button in-line remote.
  • Avanti C - Premium, ergonomically designed on-ear headphones with 40 mm drivers to create a rich sound and immersive soundstage. Includes USB-C and 3.5 mm audio cables for use with compatible iPad Pro, iPad Air, MacBook, and iMac.
  • USB-C Digital Audio Adapter with charging - Simultaneously charge your device while listening to lossless audio via 3.5 mm connector. Includes a 24-bit/48 kHz DAC.
  • USB-C Digital Audio Adapter - Converts the signal coming from your USB-C port into analog audio via a 3.5 mm connector. Includes a 24-bit/192 kHz DAC.
  • AUX to USB-C Cable 4ft. (1.2 m) - Connect your iPad, MacBook, or iMac to an amplifier or set of external speakers to enjoy lossless audio output. Includes a 24-bit/192 kHz DAC.

 

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