MASTERING SPECS & MIX PREP
FINAL MIX PREP BEFORE MASTERING
Before you upload final mixes for Heavy Mastering or Beyond Heavy, send the cleanest, most complete version of the mix you have. The goal is simple: no damaged files, no lossy conversions, no accidental clipping, no mystery versions, and enough information to prepare the right masters for vinyl, streaming, CD, cassette, Bandcamp, digital download, or video.
What should I send for mastering?
Send stereo-interleaved WAV or AIFF files exported directly from your mix session.
Do not send MP3s, iTunes imports, WMA files, YouTube rips, or any other lossy conversion as the source for mastering. If the mix only exists as a lossy file, say that clearly before uploading so we can decide the best path.
Export at the native sample rate and bit depth of the session. Do not upsample, downsample, convert bit depth, or add dither before mastering unless specifically requested.
Keep the files clearly labeled:
Artist Name – 01 – Song Title.wav
Artist Name – 02 – Song Title.wav
If the release has a final sequence, include the track order. If the release is for vinyl, include intended Side A / Side B splits, RPM if known, and any timing concerns. If you already have ISRC codes, UPC, label copy, or CD-Text info, include that too.
Should I remove the limiter from the mix bus?
Yes, unless the limiter is an essential part of the approved mix sound.
For mastering, the safest version is usually the final mix with no limiter, clipper, or loudness maximizer on the stereo bus. Avoid printing mixes that are already slammed into 0 dBFS. Leave the mix dynamic enough to shape during mastering.
If your mix bus compression, EQ, saturation, or clipping is part of the sound, do not remove it blindly. Print both versions if needed:
Final Mix – With Mix Bus Processing
Final Mix – No Limiter
Then explain which version you have been approving.
How much headroom should the mix have?
Leave clean headroom and avoid clipping. A practical target is peaks around -6 dBFS, but the exact number matters less than avoiding distortion, limiting, clipping, or accidental overloads.
Do not normalize the mix. Do not make it louder just to impress anyone before mastering. A quieter clean mix is better than a loud damaged mix.
Should I master my own reference before sending files?
You can send a loud reference version if it helps communicate the direction, but it should be clearly labeled as a reference, not the source file.
Recommended upload:
Song Title – FINAL MIX FOR MASTERING.wav
Song Title – LOUD REFERENCE ONLY.wav
The mastering source should be the clean mix. The loud reference can show the energy, density, or aggression you are aiming for.
What notes should I include?
Include anything that affects the final master:
Release title
Artist/band name
Final track order
Main contact email
Deadline or release date
Label or pressing plant, if applicable
Formats needed: vinyl, streaming, CD, cassette, Bandcamp, digital download, MP3, YouTube/video
Reference masters, if useful
Songs that should hit harder, feel darker, stay more open, or preserve more dynamics
Known problems in the mix
Vinyl side splits and RPM, if known
ISRC codes, UPC, CD-Text, or metadata, if available
You do not need to have every manufacturing detail finished before contacting us. If something is not final yet, say so.
What master formats can I request?
Heavy Mastering and Beyond Heavy can be prepared for the formats your release actually needs.
Vinyl masters usually require high-resolution WAV files prepared for Side A and Side B, with attention to side length, level, low end, sequencing, and pressing plant requirements.
CD masters are usually delivered as a DDP image with PQ information, ISRC codes, UPC, CD-Text if provided, and a cue sheet when needed.
Streaming and digital masters are usually delivered as individual WAV files prepared from the approved master. The goal is not to blindly chase a platform number. The goal is a master that sounds right, translates well, avoids avoidable encoding problems, and works across real-world playback.
Bandcamp and digital download masters are usually high-quality WAV files suitable for direct sale, download, and conversion by the platform.
Cassette masters can be prepared when the release needs cassette-specific delivery.
MP3 files can be supplied as convenience copies, but they should not be used as the source for mastering or manufacturing.
What should I do after receiving the masters?
Download and unzip the master files.
Listen through every track before approval.
Check spelling, track order, gaps, fades, starts, endings, metadata notes, and format requirements.
Do not approve files until you have reviewed them carefully. Your approval means the files are ready for release, upload, manufacturing, or delivery to the label, distributor, or pressing plant.
For vinyl, confirm the side splits, sequence, and pressing plant requirements.
For CD, send the DDP fileset directly to the plant or manufacturer unless they request something different.
For streaming and digital release, upload the approved WAV files through your distributor.
If something seems wrong, ask before sending the masters to manufacturing.
Ready to send your mix?
If your final mixes are ready, start the project and include your format needs, release details, and any notes that will help us choose the right mastering path.
If you are unsure whether your mixes are ready, use this page as a checklist before uploading.