Stem mastering is when, instead of sending a stereo mix for mastering, you divide the mix up into groups of tracks, or stems, and export those stems separately and send them for mastering.
The simplest example is exporting the vocal and separately to the backing track.
The main advantage of sending stems instead of a stereo mix is that it gives the mastering engineer more power and flexibility, for example in the case above we could compress or EQ the vocals separately from the backing track.
The disadvantage is that doing so can be time consuming and can push up costs.
Tick every one of these boxes before sending us stems for mastering. We may not be able to proceed if these are not checked:
If your mix is good and you are totally happy with it then there is no advantage to be gained by sending us stems instead of the stereo mix.
If everything sounds good and in balance then normal stereo mastering tools are all that are needed to get a great sounding master.
There are a number of circumstances where stems can really contribute to a fantastic sounding master:
We may contact you to ask for stems if we there’s something about the mix that we are finding difficult to resolve with just the stereo mix.