Mastering for vinyl

How cutting works

Vinyl is cut with a lathe: a stylus driven by the signal engraves a spiral groove into a lacquer (or into copper in DMM). The lateral movement of the stylus represents the Mid signal (L+R), the vertical movement the Side signal (L−R). This results in physical limits that a digital master does not have:

• Bass: requires wide excursions. Loud bass widens the groove and reduces the length of the side.
• Out-of-phase / stereo bass: generates vertical movement; with too much Side in the bass, the stylus can jump out of the lacquer or the groove can become too shallow (below the minimum depth the groove “disappears”).
• Highs: during cutting, the RIAA curve boosts the highs considerably; sibilants and loud cymbals require excessive acceleration of the stylus and distort on playback.
• Inner diameter: the linear speed of the groove drops from the edge toward the center (at 33⅓ rpm from about 50 cm/s to about 21 cm/s): toward the end of the side the highs lose definition and distortion increases (inner groove distortion).

Side length

More dynamic tracks with less bass content allow longer sides.

Preparing the master for vinyl

1. Dedicated master: ask for or prepare a version with less limiting (3–6 dB lower than the streaming master). Vinyl does not benefit from high loudness: a heavily limited master loses transients and forces the cutting level to be reduced.
2. Mono bass: HP on the Side at 80–150 Hz (or mono the bass below 100–150 Hz) already in the mix. The cutting engineer can apply an elliptical filter (LFX), but it is better not to depend on heavy intervention.
3. Sibilants and highs: careful de-essing on the vocal (5–9 kHz) and control of the cymbals; no strong boost above 10 kHz.
4. Controlled sub: steep HP at 20–25 Hz, no infrasonic energy.
5. Phase: correlation always positive, no out-of-phase content in the bass.
6. Track order: louder and brighter tracks at the start of the side, softer and darker tracks toward the end (inner diameter).
7. No clipping and no high true peaks: the lathe is not a limiter; digital peaks and distortion are cut as they are.

Delivery

• WAV 24 bit file (or 32 float) at the mix sample rate (44.1, 48, 96 kHz).
• One file per side (Side A, Side B) with the gaps decided, or separate tracks with the sequence and gap times indicated.
• Sheet with track order, durations, start times (PQ or list).
• Notes on the delicate points (intentional stereo bass, loud sibilants, end of the side).
• A test pressing should be listened to before the run: check for sibilants, distortion at the end of the side, and noise.

Differences in sound

Vinyl has surface noise (−60/−70 dB), lower stereo separation in the bass and a smaller usable dynamic range than digital, but it preserves the transients of the less-limited master. Many dance productions use 45 rpm to get more level and more defined highs.

Common mistakes

• Sending the streaming master at −8 LUFS: the engineer has to turn it down and the result is flatter than a dedicated master.
• Wide stereo bass (unison synths, wide 808s, reverbs in the bass).
• Uncontrolled sibilants: obvious distortion on playback.
• Sides that are too long with a lot of bass: low cutting level and more noise.
• Brightest, loudest track as the last one on the side.