Hi-Res Audio: The Basics

HI-Res Audio logo
Sony Europe

When it comes to music, the main way most of us listen is via streaming on portable devices, such as the iPod and smartphones. Although very convenient, this trend has actually taken us backward in terms of what we settle for as a good music listening experience.

What we mean by that is the file formats used by streaming services are of lower quality. When compared to the CD format, MP3 files and streamed music from iTunes, Spotify, Amazon, (and others) simply contain fewer data to make the music. In order to fit the music into a format that can be easily streamed, and provide listeners the ability to store lots of songs on a portable music player or smartphone, as much as 80 percent of the information present in the recording of the original performance may be deleted.

Enter Hi-Res Audio

As a result of the proliferation of poor-quality music listening, a strategy has been implemented to bring back high-quality two-channel audio by extending the capabilities of downloadable and streamable music so that it matches, or surpasses, CD quality. This initiative is referred to as hi-res audio, hi-res music, or HRA. For the purposes of this article, it will be referred to by its most common label: hi-res audio.

To take advantage of hi-res audio, you need to know the following:

  • What hi-res audio is
  • What the hi-res audio formats are
  • How to access hi-res audio content
  • What you need to listen to hi-res audio

Hi-Res Audio Defined

To better describe hi-res audio, the DEG (Digital Entertainment Group, Consumer Technology Association, and The Recording Academy [The Grammy Folks]) have settled on the following definition: "Lossless audio that is capable of reproducing the full range of sound from recordings that have been mastered from better than CD quality music sources."

The term "lossless" means that a music file contains all of the information provided in the original studio or live recording process but in digital form. A lossless file is most commonly uncompressed, but there are some compression algorithms that do allow retention of all required information.

The CD Reference Point

The CD format is considered the reference point separating lo-res from hi-res audio. In technical terms, CD audio is an uncompressed digital format that is represented by 16 bit PCM at a 44.1khz sampling rate.

Anything below the CD reference point, such as MP3, AAC, WMA, and other highly-compressed formats are considered "low-res" audio, and anything above is considered "hi-res" audio.

Audio Formats

Hi-res audio is represented in physical media by the HDCD, SACD, and DVD-Audio disc formats. However, since physical media is no longer in favor by many, there has been a strategic move to provide listeners with the ability to access hi-res audio via downloading and streaming.

Non-physical hi-res digital audio formats include ALAC, AIFF, FLAC, WAV, DSD (the same format used on SACD discs), and PCM (at a higher bit and sampling rate than CD).

What all these file formats have in common is that they provide the ability to listen to music in higher quality, but, unfortunately, their files are large, which means that, most often, they need to be downloaded before listening.

Getting Hi-Res Audio Via Downloading

The main way hi-res audio content can be accessed is via download.

The download option means that you can't listen to hi-res audio-on-demand. Instead, you download hi-res music from a content source available on the internet to your PC or other devices capable of downloading the required music files.

Two popular hi-res audio music download services are Acoustic Sounds and HD Tracks.

Hi-res audio is also available through some streaming services — more on that later.

Audio Playback Devices

The ability to play hi-res audio files requires an audio product that is compatible with the specific hi-res audio files you wish to play.

You can listen to hi-res audio on your PC, or if you have a network-connected home theater receiver that is hi-res audio compatible, your receiver may be able to access hi-res audio files from network-connected PCs or, if stored on a flash drive, plugging it into the receiver's USB port.

Hi-res audio playback capability is also available through specific network audio receivers and select portable audio players. Some brands that incorporate hi-res audio playback capability on selected digital audio players, stereo, home theater, and network audio receivers include Astell&Kern, Pono, Denon, Marantz, Onkyo, Pioneer, Sony, and Yamaha. When shopping, look for the official hi-res audio logo on the product or product packaging (Logo example at the top of this article).

You can also play some hi-res audio content (24bit/96kHz) on non-hi-res audio compatible playback devices using a Chromecast For Audio device, as well as via the DTS Play-Fi system's Critical Listening Mode on compatible Play-Fi devices.

Audio Streaming - MQA to the Rescue

Although downloading hi-res audio music files and then listening at home through your home network, USB, or copying to a compatible portable player is one option, streaming-on-the-go is much more convenient.

With that in mind, a process developed by MQA makes streaming hi-res audio files practical.

MQA stands for "Master Quality Authenticated." What it provides is a compression algorithm that allows hi-res audio files to fit into a much smaller digital space. This allows the music files to be streamed on demand, instead of going through the less convenient download step.

The result is the ability to stream hi-res audio files on-demand, just as you can MP3 and other low-res formats, provided you have an MQA compatible device. Although MQA files can be streamed, some services may either only provide a download option, or both streaming and download options.

It is also important to point out that if your device doesn't support MQA, you can still access the audio via download — you just won't get the benefits of MQA encoding.

Some of the MQA Streaming and Download partners include 7 Digital, Audirvana, Kripton HQM Store, Onkyo Music, Qobuz, and TIDAL.

Some of the MQA Hardware Product Partners include Pioneer, Onkyo, Meridian, NAD, and Technics.

For more details on streaming services and playback products, refer to the MQA Partner Page.

The Bottom Line

After years of listening to inferior audio quality from MP3s, and other compressed audio formats, the hi-res audio initiative is designed to provide music fans with high-quality listening without being tied to physical media. Both download and streaming options are provided and hi-res audio music is available through several online services.

However, to take advantage of hi-res audio listening, there are costs involved, both on the hardware and content end. Although hi-res audio capability is incorporated into a growing selection of moderately-priced stereo and home theater receivers, dedicated hi-res audio compatible network audio and portable audio players can be expensive, and, of course, the price of hi-res audio download and streaming content is higher than their MP3 and lo-res audio file counterparts.

With this in mind, despite increased audio content and product support, hi-res audio does have its detractors, with an on-going debate as to its real-world benefits for most listeners.

If you are planning to make the jump to hi-res audio listening, definitely seek out and conduct your own listening tests to see if the price of entry is worth it for you.