FLAC, DSD, MQA: understanding high-resolution audio formats

Three acronyms come up whenever high-quality digital music is discussed: FLAC, DSD and MQA. Behind these high-resolution audio formats lie opposing technical approaches, varying hardware compatibility and, for one of them, an uncertain future. This guide explains what each one actually brings to listening and how to choose based on your equipment.

Defining high-resolution audio

The benchmark remains the CD: 16-bit depth, sampled at 44.1 kHz. High resolution refers to anything above this threshold, most often 24 bits paired with frequencies ranging from 44.1 to 192 kHz for PCM files.

These two parameters do not measure the same thing. Bit depth determines dynamic range, meaning the difference between the quietest and loudest sounds. The sampling frequency sets the theoretically reproducible bandwidth.

One point deserves to be stated plainly: moving from 16 to 24 bits or from 44.1 to 192 kHz does not guarantee an audible difference. Recording and mastering quality often matter more than the numbers displayed on the cover. High resolution creates a larger container, not necessarily a better recording.

FLAC, an open lossless standard

FLAC (Free Lossless Audio Codec) compresses the signal without discarding anything. The file generally takes up 40 to 60% less space than an equivalent WAV, and decoding reconstructs all the original data, bit for bit. Nothing is lost in the process.

Two strengths explain its dominance. The codec is royalty-free, making it free for manufacturers and platforms to implement. And it plays everywhere: network players, smartphones, computers, DACs and recent car stereos.

It supports up to 24 bits and 192 kHz, covering virtually all masters sold as downloads. It has become the reference format for high-definition file sales and for most lossless streaming offerings.

DSD, the format derived from SACD

Launched by Sony and Philips in 1999 with the Super Audio CD, DSD (Direct Stream Digital) is based on a radically different logic from PCM. Instead of encoding amplitude across multiple bits, it uses a single bit sampled at a dizzying rate.

Its variants use a multiplier based on the CD frequency. DSD64 runs at 2.8 MHz (64 times 44.1 kHz), DSD128 at 5.6 MHz, DSD256 at 11.2 MHz and DSD512 at 22.6 MHz. The higher the number, the greater the precision, at the cost of larger files.

In practical terms, two extensions coexist. .dsf includes metadata (title, artist, cover art), while .dff does not. Choose .dsf when your player supports it.

Transmission poses a real constraint. The DSD bitrate does not pass natively over an optical or coaxial S/PDIF connection: you need a USB or HDMI connection to a DSD-compatible DAC, or a workaround called DoP, limited to DSD64. The format remains niche, sustained by SACD publishers and a few specialized download stores such as NativeDSD or HDtracks.

MQA, from a technical gamble to uncertainty

MQA (Master Quality Authenticated) offered an appealing idea: folding a high-resolution recording into a file the size of a standard FLAC, then “unfolding” it during playback through hardware or software decoding. The brand presented it as a guarantee of fidelity to the studio master.

The process has always been divisive. MQA is proprietary, and therefore subject to licensing for manufacturers and platforms. It is also not strictly lossless in the sense understood by bit-perfect purists, a recurring criticism from the audiophile community.

Recent history has decided its fate. MQA Ltd entered administration in March 2023, before Canadian company Lenbrook, owner of NAD, Bluesound and PSB, acquired its assets in September 2023. Most notably, Tidal, its main showcase, removed all MQA tracks on July 24, 2024 to switch to FLAC.

Today, Lenbrook is developing these patents under the MQA Labs banner, with new technologies such as AIRIA (formerly SCL6), FOQUS and QRONO, geared more towards signal processing and wireless transmission than a consumer streaming format. For listeners, MQA now mainly concerns owners of MQA DACs and files purchased before this reversal.

FLAC, DSD and MQA: comparison

Choosing a high-resolution audio format

Your equipment often decides for you. A good digital-to-analog converter plays FLAC without difficulty, from any source. DSD requires a compatible chip and a USB or HDMI connection. MQA requires a dedicated decoder, increasingly irrelevant given the format’s trajectory.

For online streaming, offerings have largely standardized around FLAC. Qobuz and Tidal go up to 24 bits / 192 kHz, Apple Music offers the same ceiling through its ALAC codec, and Amazon Music Unlimited does as well. Spotify finally launched its lossless tier in September 2025, in FLAC, but capped at 24 bits / 44.1 kHz. These high-definition subscriptions cost around €11 to €13 per month.

DSD follows a different path. It is obtained by purchasing files, extracting SACDs or using a dedicated player, rather than through streaming. If you mainly listen through headphones or on a connected system, a compatible audio network player and capable high-fidelity headphones matter just as much as the format you choose.

Should you aim for the highest possible definition

The race for megahertz is somewhat misleading. A poorly mastered DSD512 file will sound worse than a 24-bit FLAC from a carefully recorded production. The format is only one link in the chain, and rarely the most decisive one compared with the quality of the recording, the master and the rest of your Hi-Fi system.

In practice, FLAC has established itself as the pragmatic solution: open, universal and sufficient for the human ear in virtually all cases. DSD retains its place among SACD enthusiasts and users of specific catalogs. MQA, meanwhile, increasingly belongs to the past of streaming, even if its patents are finding a second life in signal processing. The right approach is not to chase the highest number, but to match the format to equipment capable of reproducing it.