Vinyl mastering is the final preparation of a recording so it can be cut into a groove and played with a stylus without distortion or skipping. It is related to normal audio mastering, but it deals with the physical limits of a spiral groove.
Why vinyl needs its own preparation
A digital file can hold almost any waveform. A groove cannot. The stylus has to physically follow the groove, so very large movements, harsh high frequencies or loud, heavily limited audio can make the needle distort or lose contact. A master prepared for streaming is not always safe to cut as it is.
What a mastering engineer adjusts
- Bass in stereo: strong low frequencies that differ between left and right can create large movements of the stylus. Engineers often make the deepest bass more centred, sometimes by summing low frequencies to mono.
- Sibilance: harsh “s” and “t” sounds can cause distortion on playback, so de-essing may be applied.
- Loudness and dynamics: extremely compressed masters tend to be harder to cut cleanly. A wider dynamic range usually cuts more comfortably, though loudness choices vary by genre and by engineer.
- Phase: out-of-phase material can push the stylus vertically, so engineers check for it.
- Equalisation: records are cut with a standard curve, called RIAA equalisation, which reduces bass and boosts treble when cutting. Playback reverses this, which is why a turntable needs a phono preamp stage.
The precise settings are judgement calls, which is why different engineers can produce different results from the same mix.
Side length and track order
A groove needs room, and louder or bassier music needs more of it. As a general rule, shorter sides allow louder and fuller cuts, while very long sides force compromises. Engineers also plan track order. Many albums place quieter or simpler songs near the end of a side, because the groove near the centre is harder to track.
Inner groove distortion
As the stylus moves toward the centre, the groove passes under it more slowly, and high frequencies become harder to track. This can cause a loss of treble or distortion near the end of a side. Choosing the right closing track and managing high frequencies helps reduce it. The structure of the groove is explained in anatomy of a vinyl record.
From master to lacquer
Once the audio is prepared, the engineer sets groove spacing, often with variable pitch that adapts to the music, and cuts a lacquer on the lathe. The cut is then checked, often with a test pressing, before plating and pressing begin. See how records are made for the rest of the route. A small run can skip plating through lathe cut vinyl.
What to supply
Artists are usually asked for a final mix or master in a high-quality file format, with side breaks and track order decided, and notes on any special requests. Plants and mastering engineers publish their own specifications, so follow those over general rules.
Is vinyl mastering worth it?
If you are releasing music on vinyl, a vinyl-aware master is generally considered a sensible step, since problems are hard to fix after pressing. For a casual project you may still get an acceptable result from a good general master. It is a choice about budget and expectations.
Half-speed and other special approaches
Some releases are cut at half speed, with the source slowed down during cutting, which can make it easier to capture high-frequency detail. These practices are common on premium reissues. For how those releases are marketed, see what audiophile vinyl is.