How to Prepare Stems for Online Mixing: Export Settings and a Pre-Upload Checklist

A mixing engine can only balance what it can hear separately. A finished stereo file locks in every decision you already made. Separate stems let the engine set the level of each part against the others, clean the vocal, make room for it in the beat, and then master the result.

• Format: WAV (or AIFF) is best. MixTrackLab also accepts MP3, FLAC, M4A and more, but lossless is better for quality.
• Bit depth: 24-bit is ideal.
• Sample rate: keep your project's sample rate (44.1 or 48 kHz are common).
• Start point: every stem should start at bar 1, even if the part does not play until later, so everything stays aligned.
• Length: all stems should run to the same end.
• Mono or stereo: export a mono source as mono and a stereo source as stereo.

• Leave headroom. Peaks around -6 dBFS on each stem are a safe target, and no stem should clip.
• No limiter on stems. Limiting is a mastering job and flattens the dynamics the mixing engine needs.
• No master-bus processing. Turn off the master compressor, limiter and EQ before you export.
• Dry vs processed. If a stem has heavy effects such as big reverbs or delays, export a dry version if you can, or at least keep the effects tasteful. The engine adds its own space.
• Keep your creative sounds. Intentional distortion or filtering that defines the song should stay.

Clear names help the engine and you. Use names such as lead_vocal.wav, backing_vocals.wav, ad_libs.wav, drums.wav, bass.wav and music.wav. If you have several of the same kind, number them (backing_vocals_1.wav, backing_vocals_2.wav).

If you have a lead vocal and a finished instrumental, you only need two files. If the instrumental is already a mastered track, say so in the studio so the engine balances the vocal against it without reprocessing the beat.

• All stems start at the same point and end together.
• No stem clips, and peaks have headroom.
• No limiter or master-bus effects on any stem.
• Stems are clearly named.
• You have a reference song in the same genre for comparison.
• You have a backup of your project.

When you are ready, open the studio. For a deeper look at what each step does, read AI mixing vs AI mastering.

Can I upload a .zip of stems? Yes. A single .zip of stems is accepted.

Do I need to export every stem? Group related parts if you have a lot of them, for example all drums together. You do not need a hundred tracks.

What if I only have a finished song? You can master it, but the mixing balance is already fixed. Going back to the separate parts gives better results.