STEMS is Native Instruments latest forward thinking move in DJing. It’s an “open source” (the format and usage is free to use and implement for anyone without having to pay a license fee) multitrack audio format. A stem file consists of 4 separate stereo tracks, usually divided into drums, bassline, melody and vocal but this is completely up to the artist/label how this is divided. The Stem file also contains the master stereo track to allow normal playback on software like iTunes and Windows Media Player and other DJ software / CD players. Since the format is open source it could mean that if Ableton Live for instance decides to support it, it could lead to interesting and unofficial remixes and not just used for DJing.
Playing Stem files in a supporting software like Traktor (2.9 and up) you have the ability to control individual volumes of the 4 Stem parts basically giving you the possibilities to do your own version of a track by filtering out the vocal or take a bassline from another Stem track and overlay on the first track. Using Stems you are not limited to a basic EQing to mix but having full control of the 4 stems allow you to do some very interesting mixing and live mashup. With Traktor you also have the option to apply filter on individual Stem parts as well as the FX send amount per part. This is very handy if you want to apply a huge reverb on the vocal part but not the drums.
Having been given early alpha access to the Stems Creator Tool from Native Instruments I have to say it’s a very solid and easy to use application. You have four slots you can drop in your Stem parts, name them and select a colour for each part. The name and colour are shown in compatible controllers like the D2 or S8. You also have a slot for the master file as well as fields to input track name, artist, label, artwork etc. There is also a compressor & limiter section which you use to get the output between the master file and the 4 stems as close as possible (there will be differences as the mastered stems and the master file won’t be 100% identical). There is also a preview button to play the track and you can swap between the stem version or the master version in real-time to hear how they compare. When you are satisfied you hit the ‘Export’ button and the .stem.mp4 file will be generated, a process that takes less than a minute. One thing to consider is that the file size will be roughly 4 times as large as a normal MP3 track due to containing 4 additional stereo files.
I have become a huge supporter of Stems after using them in my sets over the last few weeks and I hope that the format will take off and start to become the norm. Native Instruments Remix Sets weren’t a huge success unfortunately and I think thats down to adoption and its complexity to use in a live situation. There are a few things that concern me in the success of Stems; firstly the additional work and costs incurred from having to master not only a track but also the 4 Stem files might put a lot of labels off. Secondly, the format also needs to be adopted by other developers like Serato and Pioneer to make it interesting for labels to release Stem versions so its not only for Traktor DJs. I also feel that even though the price of a Stem version is a lot higher than a normal track (£2.25 for a Stem compared to £1.30 for normal track) due to the additional costs, I think the price needs to go down for people to adopt this and go for the Stem version instead of the normal track.
Personally I feel that Stems are the next step forward and DJing with Stems opens up new possibilities when mixing. It does require more thought and preparation to use the Stem side of things but also the spur of the moment mixing and looping of parts brings a whole new side to DJing and it feels more involved and interactive. I am already working on getting my own label Lowbit to fully support Stems on every release from here on forward.