Several streaming services now offer lossless audio, and some offer hi-res on top of that. Artists see the badges and ask whether they need to prepare special files for each tier. In almost every case the answer is no. You need one good master in WAV, at the resolution it was really made in, and the platforms take it from there.
Lossy, lossless and hi-res in plain words
Most everyday streaming is lossy. The service compresses your music into a smaller format, which throws away information that most people will not notice on a phone or a bus. MP3 and AAC are well-known lossy formats.
Lossless means the stream keeps all the information in the file it was made from. When people say "CD quality", they mean lossless audio at 16-bit and 44.1 kHz, the standard that has been around since the compact disc.
Hi-res usually means lossless audio above CD quality: 24-bit, often with a higher sample rate such as 48, 96 or 192 kHz. Each service uses its own label and its own threshold, and the tiers, plans and devices that support them change over time. If it matters to you, check each platform's current information rather than relying on what you heard a year ago.
What the platforms do with your file
You don't upload one file per quality tier. You deliver a single master file, and each platform creates the versions it needs from it: compressed streams for normal listening, and lossless streams where it offers them.
That means the file you deliver sets the ceiling. If your master is 24-bit at 48 kHz and the platform supports that resolution, listeners on a lossless or hi-res tier can hear it as delivered. If your master is 16-bit at 44.1 kHz, it will be offered as CD quality at best. A platform cannot add resolution that was never in the file.
It also means your normal, lossy listeners hear a version made from the same master. A clean, well-balanced master matters far more for them than any badge.
Deliver the best master you have, in WAV
The rule is simple: send the best genuine version you have, in the format your distributor asks for. Most distributors take WAV, and CULT accepts audio as WAV files.
In practice:
- If you recorded and mixed at 24-bit and 48 kHz, ask your mastering engineer for a 24-bit, 48 kHz master and deliver that, as long as your distributor accepts it.
- If your master only exists at 16-bit and 44.1 kHz, for example an older song mastered for CD, deliver that. It is lossless and perfectly fine.
- Keep the highest-resolution master in your archive, even if you also need a 16-bit copy for some other use.
- Check your distributor's accepted sample rates, bit depths and channel formats before you export. These requirements differ and can change.
Take an invented producer, Ora Linden. She tracks and mixes at 24-bit, 48 kHz. Her mastering engineer sends a 24-bit, 48 kHz WAV, and that is the file she uploads. She doesn't make a 96 kHz version, a 44.1 kHz version and a hi-res version. One file covers every tier.
Why you shouldn't upsample
Upsampling means converting a file to a higher sample rate or bit depth than it was made at, for example turning a 44.1 kHz, 16-bit master into 96 kHz, 24-bit. The file gets bigger and the label looks better, but nothing new is added. The extra space is filled with nothing that was ever recorded.
It can even cause problems. Every conversion is a chance for small errors, and some stores and quality programmes check whether a file labelled hi-res really contains high-resolution content. A fake hi-res file can be flagged or sent back, depending on the platform.
The same goes for converting an MP3 into a WAV. The result is a big file with all the losses of the MP3 still in it. If an old song only exists as an MP3, look for the original project or a backup and export again from there.
Common questions
Will listeners hear the difference?
Some will, many won't. Most people listen on phones, laptops or wireless earbuds, and many Bluetooth headphones receive compressed audio anyway. Listeners with good headphones or speakers on a lossless tier may notice more space and detail, especially in acoustic, jazz, classical and carefully produced electronic music. Delivering a good master costs you nothing, so do it, but don't expect a hi-res label to bring you more streams by itself.
Is Dolby Atmos the same as hi-res?
No. Dolby Atmos and other spatial formats are a separate mix with its own files and its own delivery process. Hi-res is about the resolution of the normal stereo master. They can exist side by side, but one doesn't replace the other.
Do I need a separate master for lossless?
No. One stereo master is enough. What you may want is a little true-peak headroom below 0 dBFS, because the conversion to lossy formats can push peaks over the top. Many engineers leave around 1 dB for that. Ask your mastering engineer what they aimed for.