10 Essential Vinyl Mastering Terms You Need to Know
The process of vinyl mastering involves a number of unique steps and machines that come with their own terms. Here are the ten essential terms you’ll need to know to speak “Vinyl Mastering” with the pros.
Vinyl mastering for timeless sound.
In an era dominated by streaming, vinyl has made a powerful comeback—not just as a nostalgic collector's item, but as a legitimate, high-fidelity listening format. But unlike digital distribution, vinyl requires a unique approach to mastering that ensures your music translates well to wax. If you're planning a vinyl release, vinyl mastering isn’t just recommended—it’s essential.
Cutting Lathe
The highly precise, specialized machine used to physically carve the audio signal into the master disc (either lacquer or copper). It is the heart of the vinyl mastering process.
Lacquer Disc (or Acetate)
The soft aluminum disc coated in nitrocellulose (a lacquer) that is used in the traditional cutting method. The grooves are cut into this disc, which is then used to create the metal stamper.
Direct Metal Mastering (DMM)
An alternative cutting process where the groove is cut directly into a copper-plated metal disc, skipping the soft lacquer stage. DMM cuts are generally known for less surface noise and greater high-frequency clarity.
RIAA Equalization Curve
A standardized equalization (EQ) curve applied during the cutting process and then reversed during playback by your turntable's preamp. It drastically reduces bass and boosts treble during cutting to save groove space and prevent skipping.
Groove Excursion (or Modulation)
The physical movement or width of the groove on the record. High-amplitude (loud) and low-frequency (bass) signals cause the groove to widen, requiring more disc space and limiting the total playing time.
Mono Bass
The requirement that low-frequency content (typically below $\sim 100\text{ Hz}$) must be centered (summed to mono) in the stereo field. Stereo bass creates excessive vertical groove movement, which can cause the stylus to jump out of the groove.
Inner Groove Distortion (IGD)
The loss of high-frequency clarity and increase in distortion that occurs as the needle tracks closer to the center label. This is a physical limitation because the stylus travels a shorter distance per revolution.
Sibilance
Excessive high-frequency sounds, particularly from "S," "T," and "Ch" sounds in vocals. Sibilance can cause the cutting head to overheat and introduce severe, unpleasant distortion on the vinyl cut if not carefully tamed during the digital pre-mastering stage.
Headroom
The space left between the music's loudest peak and the maximum allowed level on the master file. Vinyl mastering requires more headroom (less limiting) than digital masters to ensure the audio is dynamic and translates cleanly to the groove.
Stamper
The final metal mold (a negative image of the grooves) created from the master disc (lacquer or DMM). The stamper is mounted in the pressing machine and used to physically press the grooves into the raw vinyl "puck."
