Remove any Master Bus Compression, Limiting, and Equalization
Many times mixing engineers pre-master their tracks to get a better sound.
While the pre-master may sound better, adding processors to the master bus makes it difficult if not impossible for the Mastering Engineer to make a great master.
In rare instances producers may use a special processor or plug-in on the master bus for effect. If so, make sure to notify your mastering engineer when you send in the project.
Keep the Max Levels of Each Track Between -3db and -6db
By giving the mastering engineer enough headroom to work with he’ll be able to give you a better final master.
You don’t want to have clipping on any of the tracks in your mix.
It’s important to make sure EVERY TRACK has enough headroom.
Do not just lower the master bus, but every single track in your mix.
Eliminate Noise on the Mix
Mastering will make your song louder and potentially highlight any imperfections that may not be noticeable when mixed down.
If you can hear a problem in the mix, you will definitely hear it in the final master.
Remember to remove any pops, clicks, background noise, and anything else that is bothersome.
Mastering Engineers can remove some noise; however you’ll get a much better master if you fix it in the mix.
Keep Your Mix Clean and Dynamic
Reduce frequency buildups that are not the main focus of the song. Frequency buildups can make a mix sound unclear or 'muddy".
Using low-pass filters for instruments or vocals that have little low frequency content helps reduce these buildups.
Leave your mix dynamic.Overuse of compression can take the life out of a song.
This makes it difficult for the Mastering Engineer to create a great sounding master.
It's best to leave mixes as dynamic as possible. Doing so gives the Mastering Engineer space to sculpt the dynamics to create the best possible master.
Submit the Highest Resolution File You Have
You will want to make sure to submit your files in the same resolution they were mixed at.
Generally speaking you will want to submit a 32 or 24bit .WAV or .AIF file with a sample rate of 96kHz.
These files are lossless (non-compressed or converted) and will give the Mastering Engineer the best options when mastering.
Most any file can be mastered, but the final quality will suffer when using lossy formats such as MP3’s.
Submit Reference Songs and Notes
A good Mastering Engineer knows what commercial levels are and will be able to match your musical genre to these levels.
However within each genre there are often differences in equalization and compression.
Likewise many artists want a specific sound with their master.
For this reason it’s very helpful to let the Mastering Engineer know any song references that have a similar sound to what you want.
Also adding notes is helpful so the engineer knows exactly what you are looking for. This can help reduce revisions and costs.
Do Not add Fades, Cross Fades, or Spaces
Your Mastering Engineer will add song fades. Leave this up to him and you’ll get a better final master.
If you have special requirements for spacing between tracks make sure to let your engineer know. Redbook standard gap is 2 seconds.
Remove any Dithering
As with fades, dithering will be added by the Mastering Engineer.
If you’ve pre-mastered your track with dithering, or other plug-ins designed to “enhance” the sound you will want to remove them.
Dithering is best left to the Mastering Engineer so that the correct settings are used for your track.
Reference Your Mix
Listen to songs that you want your mix to sound like. It’s important to do this both during the mixing process and especially toward the end of the mix.
Compare levels, compression, equalization, effects etc. This can give you a good idea of what you might want to fix, change, or modify.
Also, listen to your mix on different playback systems such as your home stereo, car stereo, headphones, and even ear-buds.
This will help you make adjustments so your song sounds it's best on all systems.
Above All Make Sure Your Mix Sounds Like You Want
This is possibly the most important.
So often after mastering a song the artist will decide they are not happy with the way they mixed the track, or want a track replacement.
The re-mix will then require re-mastering. Artists should remember that mastering is not a magic fix all and you’re not going to get a great final master if you don’t have a great mix.
Mastering will bring out both the best and worst in your mix so it’s important to iron out imperfections before submission.