Benefits of Stem Mastering

What is 2 bus ?

One of the most common questions in mastering is whether one should go for a simple 2 bus or stem mastering. First of all get the basics right. 2 bus means stereo master track. Back in the old days when hits were mixed on big consoles there was lot of channels that were grouped. The console world calls them on various names like group channel or buses. A typical mixing consoles operates with send return effects and these channels are often refered to as the aux bus or in short aux. The main summing group or master channel was used to call “2 bus” as it is including all channels that are summed to a stereo channel. This stereo channel than got the master effects and fed in to the recorder apparatus. Now that the 2 bus question is clear let’s talk about stems!

What are Stems?

Stem mastering is a quite new trend it was becoming more popular in the market about 10 years ago mainly because of the rise of electronic music. Stem mastering and mixing is often mixed up but it is a big mistake. While traditional mixing operates with all of the elements of the song including effects on separate channels and layers also split into channels, stem mastering is only operates with the most important key elements that are separated to channels but a lot of finedetails cannot be edited as layers and effects are merged into a stem.

So what is a stem? Stem is a logically grouped and merged musical element of a song presented on a stereo or mono channel for the mastering engineer. Stems logical order serve the idea of being able to finetune but without the need of deep diving into the project. This results in much less working hours and of course less cost to the artist comparing to a mixing session. You might ask what the hell electronic music had to do with the rise of stem mastering in the industry?

Stem mastering & Electronic Music

As electronic music entered the loudness war and became more loud from year to year, this reduced dynamic range resulted in the absence of space for composing complex structures so the tracks became more simple but louder. As there wasn’t room for a lot of elements the few that remained to entertain the listener had to be really good. Traditional mixing was too pricey and mixing engineers also realised that they don’t want to deal with so simple 8-10 track music and aiming mastering for loudness on the workflow, so a new breed of engineers came to life as the market demanded and this is how stem mastering specialised services started to fill the gap between traditional services and artists needs.

Stems on an electronic music typically includes the kick, the snare/clap, the hihats, the grooves, these four are covering the drums. The next four used to be the bass, lead, chords, arpeggio, these cover the melody and harmonies. The last four is typically the effects, the vocal, the chorus, piano/guitar. Now you see that instead of having everything already merged together into a stereo track a stem mastering project have about 8-12 tracks with the most important elements. This helps a lot for the engineer as so many options come avaliable with stems the guarantees better results over a 2 bus mastering session. For example if We need to deal with the bass, there is the option to deal with the kick separately,with stereo mastering if We apply an equaliser for the bass region, both the kick and all the basses will be effected simoultanously, while with stereo mastering We can process them separately, thus be able to solve problems that can’t be done with a 2 bus mastering session. For example if they are clashing aka fighting for space in the same frequency domain, We can only separate them in stem mastering process. Same with melodies, if a synth group would benefit some analog tape saturation juice to really give them the vibe, they can only be processed separately if We have the stems as if We flip that saturation for the 2 bus version not only the synths but all the drums and basses would be saturated and those are more sensitive to this process so an inbalance would be introduced that need to be compensated which is rather harder to deal with than a precisely aimed processing with stems.

Stem Mastering is Really a Win – Win

Easier for the engineers as they won’t get tired or lost in the countless channels so tend to give a better overall perfomance on the task. Better for the artist as processing time is much faster and gives much better results with lower costs. One last thought from the artists point of view: Sending the tracks for mixing usually involves a lot of exporting and structuring all elements optimised for the mixing process, a lot of questions come to mind, what plugin is considered as a sound design element and which one should be bypassed and so on. These are working hours that a professional artist should factor in for the production cost. Its always a relief to skip this difficult task and to tell the truth sometimes it is completely unnecessary as the basics are layed down so good that only the icing on the cake is left for the engineer. Next time when You send your track for mastering think about this!