Guide · Stem Mastering

Stem mastering: more control over your mix

Stem mastering masters several track groups, such as drums, bass, guitars and vocals, instead of one stereo file. It helps when instruments mask each other in the mix. At Polished, stem mastering costs €129 per track incl. VAT, with a written audio audit and unlimited revisions.

Request stem mastering → How to export stems

By Tim Borchert, mastering engineer · Updated October 2026

Stereo vs. stem mastering

	Stereo mastering	Stem mastering
Source	one finished stereo file	4–6 track groups (stems)
Processing	always affects the whole mix	targeted per group
Best when	the mix is well balanced	elements collide or a group is too loud/quiet
Price at Polished	€79 per track	€129 per track

Typical metal cases for stems: kick and bass fighting below 100 Hz, guitar walls masking the vocals, cymbals covering the snare in blast beats, or sub drops eating the headroom in breakdowns.

How to export stems

Group tracks: usually drums, bass, guitars, vocals, plus keys/synths and FX (reverb and delay returns) if needed.
Same start, same length: every stem starts at 0:00 / bar 1 and ends at the same point.
Format: 24- or 32-bit WAV at your session's sample rate.
Null test: all stems together at 0 dB must reproduce your mix exactly.
No master-bus processing: turn off limiters, clippers and bus compression. Group processing that is part of the sound can stay.
Effects: render reverb and delay into the stem or export them as a separate FX stem, never both.
Headroom: no clipping; leave about 3–6 dB below 0 dBFS on the sum.
Naming: e.g. SongTitle_Drums.wav, SongTitle_Bass.wav.

Include the stereo mix as a reference and one or two reference tracks from your subgenre. Pricing compared to other providers: How much does mastering cost?

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Stem mastering service: prices

Package	Price incl. VAT	Scope
Stem single	€129	1 track, up to 6 stems, audio audit, 48–72 h
Stem EP	€549	up to 5 tracks, €96 less than 5 stem singles, 5–7 days
Label partner stem single	€103	from 4 releases per year

All stem mastering services at Polished include the written audio audit, streaming and Bandcamp exports and unlimited revisions. Not sure whether stems are worth it for your mix? Send the stereo mix first and the audit will tell you.

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Stem mastering FAQ

What is stem mastering?

Stem mastering masters several track groups (stems) such as drums, bass, guitars and vocals instead of one finished stereo file. Each group can be processed individually before everything is combined into the final master, which gives more control when instruments mask each other in the mix.

When is stem mastering worth it?

Stem mastering is worth it when elements in the mix collide, for example kick and bass in the low end, guitars masking the vocals, or cymbals swallowing the snare during blast beats. For a well-balanced mix, stereo mastering is enough. The Polished audio audit tells you which one suits your mix.

How much does stem mastering cost?

At Polished, stem mastering costs €129 per track with up to 6 stems, and the Stem EP (up to 5 tracks) costs €549, €96 less than 5 stem singles. All prices include 19% VAT, the written audio audit and unlimited revisions.

How many stems do I need?

Usually 4 to 6 stems: drums, bass, guitars, vocals, plus keys/synths and FX if needed. More stems are not automatically better; what matters is that related tracks share a group and that all stems together reproduce your mix exactly.

Is stem mastering the same as stem mixing?

No. Stem mixing rebuilds the balance of a song from its stems and changes the mix itself. Stem mastering keeps your mix decisions and only uses the stems to fix what a stereo master cannot reach, for example a bass that masks the kick or vocals buried under the guitars. Polished offers stem mastering, not mixing; if the audio audit shows the mix itself needs work, you get an honest note instead of a hidden remix.