How to Prepare a Mix for Mastering: Headroom and Export Checks

To prepare a mix for mastering, send a clean stereo WAV or AIFF with the balance you want, no unintended clipping, and enough level below the digital ceiling to work comfortably. Check any loudness limiter, keep the processing that defines your mix, and listen to the actual export before uploading it.

You do not need to force every mix to exactly -6 dBFS. A peak number alone cannot tell you whether the vocal sits right, the drums still have punch, or distortion is already printed into the recording.

1. Finish the mix decisions first

Listen to the chorus and a quieter verse at a comfortable volume. Can you follow the lead vocal? Does the bass cover the kick? Are the effects where you want them?

If the vocal is buried only in the hook, fix that relationship in the mix. Mastering processes the combined stereo file; it is not a dependable replacement for adjusting separate tracks. iZotope's mastering guide makes that distinction and recommends resolving balance before bouncing.

2. Check headroom without chasing a magic number

For a fixed-point digital export, 0 dBFS is the ceiling. Leave your highest peaks below it. Several decibels of space is a practical starting point, but follow your mastering engineer's requested specification rather than treating one number as a universal rule.

Watch the loudest section, then listen. Turning down an already distorted file lowers its level; it does not undo distortion that was printed earlier. Check track and bus processing as well as the final output. See iZotope's explanation of headroom for the difference between available level and clipping.

3. Separate your mix sound from a loudness preview

A limiter used mainly to make a listening copy louder can leave less flexibility for mastering. Try bypassing it or reducing its action, then compare at similar listening levels. Do not automatically strip off your mix-bus EQ, compression or saturation if those choices are part of the approved sound.

If removing the limiter changes the feel significantly, send a clearly labeled limited reference alongside the less-limited mix and explain what you want to preserve. iZotope's mix-delivery guidance supports this approach. The reference communicates intent; label it so nobody mistakes it for the processing source.

4. Export the stereo file deliberately

• Format: use a lossless WAV or AIFF. An MP3 listening copy is useful as a reference, but converting an MP3 to WAV does not restore lost information.
• Resolution: keep the project's sample rate and use the bit depth agreed with the engineer. Do not upsample just to make the specifications look bigger.
• Range: include the complete intro and ending. Leave enough time for the intended reverb and delay tails.
• Normalization: check the export setting so the bounce does not unexpectedly change level.

In Logic Pro, Normalize Off leaves normalization unapplied. On raises the highest peak toward the maximum level; Overload Protection Only reduces overloads. For preserving your chosen bounce level, select Off and check the resulting file. Apple's project-bounce instructions explain those options and the audio-tail settings.

5. Check the file you are actually sending

Import the export into a fresh track or play it from the destination folder. Listen from the beginning through the final tail. Check for a missing vocal, accidental solo, clipped ending or wrong version. Avoid routing the imported bounce through the same master processing again.

Use a name such as Song Title — Mix for Mastering — v3.wav. Label an alternate loud reference separately. In your note, identify the approved version and explain the qualities you like in a reference track, rather than asking for an exact copy of another artist's sound.

Choose the right handoff

If the stereo mix is finished, explore MixedByEl's Master service and check the current order and file-submission details before booking.

If you still need separate vocals and instruments balanced, start with the Mix service. Use the vocal file-prep checklist for that different handoff. Sending a stereo file for mastering and sending separate tracks for mixing solve different problems.