Mix delivery checklist: what to check before you send

The mixing took forty hours. The delivery takes thirty minutes, and it decides whether those forty hours land cleanly or come back with an apologetic email. The checklist below is the boring, repeatable version of that half hour. Print it, or keep the page open while you bounce.

1. Before you bounce

• Confirm the session sample rate. The mix should leave at the rate it was made at, commonly 44.1 or 48 kHz. If a video edit is the destination, 48 kHz was hopefully agreed before you started, not discovered now.
• Bypass anything that isn't part of the mix. Reference plugins, loudness meters set to insert mode, a monitoring EQ on the master bus. Solo nothing, mute nothing that should sound.
• Check the mix bus for a forgotten limiter. If mastering comes next, the bus stays clean (more on this below). Bouncing through a limiter you meant to bypass is the single most common way a delivery goes wrong twice.
• Listen to the whole render once. Not the session, the bounced file, start to finish. Clicks, a dropped clip, a fade that didn't print: these only show up in the file.

2. The render settings

• 24-bit WAV at the session's sample rate. No rate conversion on the way out, no MP3 as the master copy.
• Headroom, without superstition. Peaks around −3 to −6 dBFS is a comfortable habit, but nobody rejects a clean mix over the exact number. What matters: no clipping, no limiter doing the work loudness should not be doing yet.
• No mix bus limiter if mastering follows. If the client wants to hear it loud, print a second file through the limiter and label it as the loud reference. Deliver both, clearly named, and the mastering engineer works from the clean one.
• Dither only when you reduce bit depth. Staying at 24-bit means no dither. It gets applied once, at the final 16-bit conversion, which is usually mastering's job, not yours.

If the next stop is a mastering engineer, their side of the handoff has its own reference: mastering delivery formats.

3. What goes in the delivery

• The main mix. Full resolution, the file everything else orbits.
• Agreed alternates. Instrumental, TV mix (lead vocal out, backing vocals in), a clean version, an a cappella. "Agreed" is the load-bearing word: alternates are quick to print now and a paid change order later, and both of those are fine as long as everyone knew which one this is.
• Stems, if they're in the deal. Stems are their own discipline, with their own ways to go wrong: how to send stems to a client.
• A labeled MP3 reference. For the car and the phone speaker. The label matters because the one thing an MP3 must never do is get mistaken for the deliverable.
• A short notes file. Tempo, key, session sample rate, what's printed into the mix, and which file is which. Three lines of text that save three emails.

4. Naming

One convention, no exceptions: Artist_Title_Mix_v3_2444.wav. Artist, title, what the file is, version number, format. The version number is the whole point. A folder with final, FINAL2 and final_fixed_apple in it is an incident waiting for a deadline: sooner or later the wrong file ships from it, and that happens in careful studios too.

5. The handoff itself

How the files travel matters as much as what's in them:

• Review before possession. Send a streaming review link first, so the client hears the mix losslessly and comments on the waveform instead of replying to an attachment. The whole flow is covered in how to send a mix to a client.
• Approval on a specific version. When it's right, the client approves v3, on the record. Not "sounds good" in a thread about something else. See how to get client sign-off.
• Deliver protected. Password on the delivery, a link you can revoke, download tracking, and a checksum so what they downloaded provably matches what you rendered. If the balance isn't settled, the download can wait for it: how to get paid for mixing and mastering.

The checklist

The compressed version, in order:

• Session rate confirmed, destination known
• Reference and monitoring plugins bypassed
• Mix bus clean (or loud reference printed separately)
• 24-bit WAV at session rate, no clipping
• Rendered file listened to, start to finish
• Alternates printed per the agreement
• Stems prepared if contracted
• MP3 reference labeled as a reference
• Notes file: tempo, key, rate, contents
• Everything named Artist_Title_What_vN
• Review link sent, approval recorded, delivery protected

Frequently asked questions

What format should I deliver a mix in?

A 24-bit WAV at the sample rate the session was made at, commonly 44.1 or 48 kHz. Don't convert the rate on the way out and don't deliver an MP3 as the master copy; an MP3 is fine only as a clearly labeled reference for casual listening.

Should I put a limiter on a mix I send for mastering?

No, unless the client asked for a loud reference. Leave the mix bus clean and keep true peak under about −3 dBTP so the mastering engineer has room to work. If the client wants to hear it loud, print a second file with the limiter and label it as the loud reference, next to the clean one.

How much headroom should a mix have?

There's no magic number, and mastering engineers care less about the exact figure than people think. Peaks somewhere around −3 to −6 dBFS is a comfortable habit, but a clean, unclipped mix with a sensible level is what actually matters. What you should not do is slam the mix into a limiter to make it loud before mastering.

What files should a mix delivery include?

At minimum the main mix as a full-resolution WAV. Depending on the agreement: an instrumental, a TV mix (vocals removed, backing vocals kept), a clean version, stems, a labeled MP3 reference, and a short notes file with tempo, key, session sample rate and anything printed into the mix.

How should I name mix files?

Pick one convention and never break it: artist, title, what the file is, version, then format, like Artist_Title_Mix_v3_2444.wav. The version number does the heavy lifting; "final", "FINAL2" and "final_fixed" are how the wrong file ends up on the release.