The medium
On vinyl the sound is cut as a spiral groove: the lateral movement of the stylus represents the sum of the channels (Mid), the vertical movement the difference (Side). The master is “cut” onto a lacquer (or onto copper in DMM) by an engineer with a lathe, then stampers are made and the records are pressed. Vinyl has physical limits that a digital master doesn't have: mastering for vinyl respects them.
Physical limits and solutions
- Duration and level: the longer the side, the narrower the groove must be, hence the lower the level and the less bass. Typical pressing-plant guidelines: 12" at 33 1/3 rpm up to about 22 minutes per side (better under 18–20 for quality), 12" at 45 rpm up to about 12–15 minutes, 7" at 45 rpm around 4–5 minutes per side. Always check with the plant.
- Mono lows: out-of-phase lows (Side) produce strong vertical movement of the groove that can make the stylus skip or make the cut impossible. Lows below about 150–250 Hz should be made mono (many plants indicate 250 Hz or 300 Hz as a prudent threshold). Use an HP on the Side or an “elliptical EQ”.
- Sibilance and intense highs: high frequencies at high level require enormous stylus accelerations (distortion, “broken sibilance”). Careful de-essing and control of peaks above 10–16 kHz.
- Inner-groove distortion: toward the center of the record the linear speed drops and distortion rises, especially on the highs. Put the quieter, less bright tracks at the end of the side.
- Phase and correlation: avoid negative correlation (masters with extreme wideners).
- Subsonic rumble: HP at 10–20 Hz.
- RIAA equalization: in cutting the lows are attenuated and the highs emphasized; in playback the phono preamp does the opposite; it's automatic, but it explains why extreme highs and lows are critical.
Loudness and limiter
Vinyl has no 0 dBFS limit: the cutting level is decided by the engineer based on duration and content. A heavily limited digital master does not sound louder on vinyl: the lathe decides. For this reason a separate master is often supplied, less compressed and without an aggressive limiter (peaks around −1/−3 dBFS, lower loudness than the streaming master), which preserves transients and dynamics.
Side sequencing
- Balance the duration of the sides (side A and B similar).
- Louder tracks and tracks with more low end at the start of the side.
- Gaps between tracks: indicate them in the cue sheet or include them in the files (plants usually ask for one file per side or one file per track with the gaps).
Typical delivery
24-bit WAV or AIFF, 44.1–96 kHz; one file per side or one file per track named with the side (A1, A2, B1…); cue sheet with durations and gaps; notes on any issues; no 16-bit dither. Ask for a test pressing and listen to it on several turntables before approving production.
Example in A minor
4-track EP (house and downtempo) on 12" at 45 rpm: side A = the loudest dance track (6:40) + a downtempo track (5:10); side B = two 6-minute tracks. Vinyl master: Side HP 200 Hz, a firmer de-esser on the vocal, limiter removed, peaks at −2 dBFS, 3 dB more dynamic than the streaming master. The brightest track goes at the start of side B.
Common mistakes
- Sending the over-limited streaming master.
- Wide lows and stereo reverbs on the sub.
- Sides that are too long for the chosen format.
- Not asking for the test pressing.
Exercise
Prepare the vinyl master of one of your tracks: compare the Side spectrum below 300 Hz before and after, measure the correlation, and note how much loudness you have “given back” compared with the digital master.
Links
“Mid/Side EQ in Mastering”, “Mono Compatibility”, “Formats and Delivery”, “Loudness War and Perceived Dynamics”.