How to prepare tracks for mastering?

All stereo bus processors on master channel should be turned off! Mixing with limiter + compressor on master bus or not?

All dynamic processors on master stereo bus (limiters, compressors) also soft clippers and equalizers must be turned off before exporting your song!

Limiters during mix process. Most of professional mix engineers will tell you should not mix with limiter on master bus, but most of them are secretly using this technique! 🙂 I suggest to test your mix before sending it to mastering studio with limiter turned ON to final volume levels – same RMS as you wish to have after mastering (I suggest to use Fab Filter Pro L limiter), I suggest also to put one equalizer boosting bass and trebles just for test to stereo bus. Why? Because usually your mix sound different at high levels – you hear more reverbs, stereo, quieter elements are louder, you hear more problems, more distortion, more harshness, more disharmonic frequencies and resonations etc. So feel free to constantly testing your mix with final volumes using limiter + eg during mixing, but don’t forget to turn OFF all processors, limiters, equalizers, clippers from your stereo master bus before exporting song!

Maximum volume of peaks / Headroom
Peaks (highest parts of song / mix) should be between -0.5 db -1 db but they should never be in clipping!

Too quite exported mix usually brings more noise and digital artifacts in final master, why? Because in mastering process everything must be amplified to meet commercial levels / standards – and together with music material also noise is amplified (if noise is -90db under, and music material is very quite (eg. peaks are only -10db) it usually happens that noise is amplified to levels somewhere in between -60 -50db which are audible levels. There are usually also unpleasant digital artifacts caused by distortion, compression, plug-ins generating higher harmonic, these artifacts are usually -100db under 0, but if your mix needs lot of amplification (it is too quite) these artifacts are amplified too and at audible levels like -60db they are causing lot of unpleasant harshness! With quite exported mix you are also shrinking dynamic range of record.   

Dynamics can be described as ratio between highest (peaks) and lowest parts of audio signal – bigger is difference = more dynamic your record is. Dynamics of mix is also important / it should not be very big if you want really loud master, but also cannot be small if you want to sound good, rich, musical. Dynamics of mix are usually controlled by compressors, limiters, softclippers used at individual channels in your mix.

Bit depth Resolution
24 bit resolutio

Sample rate
44.1 kHz (48 kHz is suggested)

File formats

Dithering and Noise shaping
Do not use any noise shaping or dithering when exporting your mix for mastering.

Do not use any normalization
Do not use any normalizing of exported files, some normalizers are working on dynamic principles and are damaging dynamics, some programs are automatically dithering processed wav files.

Always check exported mixdown before sending it to mastering studio

Always check your exported files to make sure no clicks, artifacts or other problems are present in final mixdown. Usually these problems are audible after export (due to technical problems which happened during export/rendering) not during real time mixing / production.