Stems

In-Depth Explanation

What are Stems?

In audio production, Stems are stereo audio files that contain a sub-mix of multiple individual tracks grouped by instrument type.

They are created by exporting (bouncing) specific groups of instruments from a DAW. When all the stems of a song are played back together at the exact same volume (0 dB), they should perfectly recreate the final stereo mix of the song.

A standard set of stems for a pop song typically includes 4 to 8 stereo audio files:

• Drums / Percussion Stem: (All kicks, snares, cymbals, and drum loops mixed together).
• Bass Stem: (Synth bass, bass guitar, 808s).
• Music / Instruments Stem: (Guitars, pianos, synthesizers).
• Lead Vocal Stem: (The main lead vocal, including its specific reverb and delay effects).
• Background Vocal (Bстую) Stem: (All harmonies, doubles, and ad-libs).

Stems vs. Multitracks (The Common Confusion)

The term "stems" is frequently misused by artists and even producers. It is crucial to understand the difference between stems and multitracks, especially when communicating with a mixing engineer.

• Multitracks (or "Trackouts"): These are the individual, raw, unmixed audio files of every single element in the session. A complex pop song might have 120 multitracks (Kick In, Kick Out, Snare Top, Snare Bottom, Guitar Left, Guitar Right, Lead Vocal Take 1, etc.). If a producer asks you to send the "stems" so they can mix the song from scratch, they actually mean they want the multitracks.
• Stems: As defined above, these are pre-mixed groupings. If a song has 15 different drum tracks, the "Drum Stem" is just one single stereo file containing the final mixed sound of all 15 drum tracks combined.

Why Are Stems Used?

Stems are incredibly valuable for several post-production workflows:

1. Stem Mastering

Sometimes a mastering engineer will request stems rather than a single stereo mixdown. If the engineer notices the vocals are slightly too harsh, but the snare drum (which occupies the same frequency range) sounds perfect, it is difficult to fix with a standard stereo EQ without ruining the snare. If they have stems, they can easily apply EQ to the Vocal Stem without touching the Drums Stem, allowing for much greater precision during Mastering.

2. Remixing

When a label commissions a DJ to create an electronic remix of a pop song, they do not send the DJ 120 raw multitracks; that would be overwhelming. They send the stems. The remixer can take the Lead Vocal stem, completely mute the original Drums and Music stems, and build a brand new beat underneath the original vocal.

3. Live Performance Backing Tracks

If a solo pop artist is performing live with just a drummer, they need backing tracks to fill out the sound. They will take the stems from the studio session, load them into Ableton Live on stage, mute the Lead Vocal stem (because the artist is singing live) and mute the Drum stem (because the live drummer is playing), and let the Bass and Music stems play through the venue's PA system.

4. Sync Licensing (Film & TV)

Music Supervisors frequently require stems when licensing a song for a film or commercial. If an action scene has heavy dialogue, the supervisor might use the Instrumental stems during the dialogue, and only bring the Lead Vocal stem back in when the actors stop speaking, allowing the song to fit perfectly around the scene's audio.