Submitting songs artists and their producers and engineers have been sitting on for so long is a taxing thing. Something is irrevocably deemed “done” and “finished” and bouncing all those tracks, recordings, automations and edits down into a single stereo file is daunting. It really should not be: if there is a slight doubt that balance will be thrown off by mastering, there is a way to adapt: stem mastering.
Just like in mixing, stem mastering is done on multiple tracks which are comprised of instrument groups from the song. How should those stems be compiled for mastering and Atmos stem mixing to succeed and to serve the artistic intent?
The Nature of Stems in Stereo Stem Mastering
As a producer and arranger logical thinking often dictates that we think in instruments – there are “guitars”, “strings”, “FX”, “drums”, “synths” and so on. Engineering-wise the situation changes dramatically: in mixing but maybe even more so in mastering, stems are defined by their respective functions in the song.
This is most evident in the case of the drum group. Drum groups are inherently stems by function as these give the backbone of the track, blending low-pitched kicks and high-pitched cymbals. In addition: snares are almost always reverberated, put in a space, whereas hi-hats are sometimes left dry to pop even more. So a drum group is a good example for a stem.
Like in Michael Jackson’s hit song, “You Rock My World”:
If you take a look at the stems uploaded here, you can see that there are two kinds of piano stems. This is exactly because they differ in function: the “Piano” stem is high energy, very much in the middle of the action since they “dictate” the chords in the song whereas the E-Piano is only an accompaniment, with much less energy in it.
All in all, in stem mastering, instruments are grouped into stems according to function.
As I already mentioned in the description for stem mastering, this is very, very far from conventional mixing and it is a last resort if something needs to be fixed or altered in the mastering stage when it comes to the overall balance of the song.
IF YOU NEED STEREO STEM MASTERING, ORDER HERE
The Desired Nature of Stems in Atmos Stem Mixing or Atmos Mastering
As I wrote in the blog post, “Atmos mastering” (again, that is the preparation of the Atmos version of a song) is always a stem mastering process where in addition to having the possibility of late adjustments, all the stems are put into a virtual space and are placed and automated according to their rule.
Most of the rules are the same here, except for two things. One, we need a separate reverb track to put the reverb itself into the space.
The other consideration artists need to make is to have small, percussive elements organized separately because those can be moved around very nicely in the virtual space.
IF YOU ARE CONVINCED ABOUT GOING ATMOS, ORDER HERE