Stems – What are they and how do you use them?

Stems – this music format from Native Instruments is sometimes called ‘the future of DJing’. Especially at launch, three years ago now. Still, our DJ and studio expert Marc van den Hurk gets the feeling the concept hasn’t quite broken through. A shame, he thinks, because it has so many possibilities! But is that really the case? And does it actually have a future? Marc takes you into the world of Stems!

Stems - Wat zijn het en hoe gebruik je ze?

Stems versus multitracks: what’s the difference?

A stem is a grouped submix: for example, you take all the drum tracks, all the synths, or all the vocals and bounce them down to one stereo file — including the effects and balance you’ve set. So what you load into the Stem Creator Tool is always already-mixed groups, not individual raw recordings.

A multitrack is different: those are the individual tracks as they sit in your DAW, each element separate. Those tracks can already include EQ or compression, but the point is that they aren’t summed into a group. With stems, you make that grouping decision yourself, before exporting.

That distinction is exactly why tools like iZotope RX or XTRAX Stems can recover separate elements from a stereo master file and also call the resulting tracks ‘stems’: they’re submixes of what’s inside the master, like all drums or all vocals together. That’s a different workflow from exporting from your DAW yourself, but the principle — a grouped submix — stays the same.

If you’re releasing your own track, you’ll build your stems in your DAW: group your tracks logically, set the balance, enable any group effects and export each group as a separate stereo file. You then load those four exports into the Stem Creator Tool, which turns them into a single .stem.mp4 file.

What are Stems?

A Stem file gives a DJ or live performer the option to play different elements of a track. A Stem file might consist of vocals, drums, bassline and lead. Native Instruments developed this technique, but at its core it’s nothing new, of course. The Beatles recorded their first record on four tracks too — on a tape machine — but these were also four separate tracks with guitar, drums, bass and vocals. DJing with two tape recorders is a bit impractical, though, so Native Instruments adapted its software and hardware to make it possible. Stems is an open technology, and is therefore available to any developer of DJ and music production software/hardware.

Stem files

A Stem file is a standard MP4 file that uses the same codec. So if you play this file from iTunes, it behaves like a normal stereo file. You can recognise the file by .stem.mp4 at the end of the filename. A Pioneer CDJ-2000 reads MP4 too, so you can play these files there without any trouble. Load the file into a Stem Deck in Traktor, however, and suddenly you have four tracks at your disposal. Just note: these are specially prepared MP4s. You can’t simply turn ‘normal’ MP4s — or any other audio file — into four tracks just like that!

Stems - Wat zijn het en hoe gebruik je ze?

How do I create Stems myself?

For producers, Native Instruments developed a Stem Creator Tool. In a DAW — Cubase, Ableton or Bitwig, for example — choose the tracks you want to combine and bounce them. Keep in mind: you can end up with a maximum of four tracks. So, for instance, combine eight drum tracks into one Stem track for the drums. In the same way, four lead-sound tracks become one track, and so on. Load the four tracks you’re left with into the Stem Creator Tool, and it will in turn create a complete Stem file. You can also name the individual Stem tracks, and those names will appear in the Traktor software.

Is it possible to make a Stem file from a stereo track?

No — well, not entirely. You can’t just pull all instruments out of a track individually. Technically, this is (still) impossible. I’ll spare you the technical details of how and why. But… I didn’t say not entirely: Audionamix has the software package XTRAX Stems, which lets you separate vocals and drums from the rest.

Native Instruments Stem Creator

How can you DJ with Stems?

The great thing about Traktor is that the software analyses all your music for BPM, but also for musical key. It does the same with Stem files. That way, in the Stem decks you can load a bassline from track A, the vocals from track B, the lead from track C and the drums from track D — all in the same key! And you can create a remix on the spot from four tracks and still have three Stem decks left over, or two remix decks for loops… et cetera, et cetera. Are you getting as excited as I am?

Stems: the future?

And yet… Stems doesn’t seem to be taking off. On Beatport and other portals where you can get music, Stem files are available to buy. There are also free Stem files, and sample-library producers like Loopmasters offer Stem files as well. On top of that, Native Instruments, as I said, offers this technology as open source. Free, for everyone. So it’s striking that major software products like Serato and Rekordbox DJ — and DAWs like Cubase, Ableton and Pro Tools — don’t embrace it or integrate it. Of course, you can still bounce your tracks into four stems and then use the Stem Creator Tool. But it would be more convenient to create a stem.mp4 file directly from the DAW. To make this more mainstream in the DJ world, you need manufacturers — Pioneer or inMusic (Numark, Denon, Rane) — to get their products ready for this format. And they can. The display on the Denon SC5000, for instance, is big enough. That player already seems capable of everything Serato can do, so why not Stems as well? And looking at music production software: you now find Ableton Link in Serato, Traktor and MASCHINE too, so why not Stems?

Response from Pioneer

Out of curiosity about how other brands feel about Stems, I asked a number of manufacturers — Serato, Denon, Rane, Stanton, Pioneer, Reloop — for a response. Keleigh Batchelor from Pioneer replied: “We’re always listening to feedback from DJs and consumers and at present we haven’t had a huge demand for Stem integration into our hardware or software. It’s definitely something to consider for the future, but for the immediate there are no plans to integrate. Stems is a great concept and to have access to open file formats in the booth and studio allows artists to elevate and expand their creativity. We always stay close to these technologies and we’re constantly evaluating if our customer demands this tech.”

Native Instruments Stems Ready

In short

So if you want to DJ with Stems, for now you’re reliant on Traktor Pro and Mixed in Key Flow 8 Deck. If you use an iPad, the DJ Player Pro app also supports Stems. As for DJ controllers, you can use any controller that Traktor supports. Naturally, Native Instruments controllers are equipped with buttons and/or faders to control your Stems. With other brands, you’ll need to map this yourself. So I think it’s down to us — DJs and producers. Get stuck into Stems, produce, DJ and show the world why you use Stems. Let the world hear that you DJ more innovatively than other DJs. Bring on Stems!

Have you started working with Stems yet? And how is it going? Leave your response below!