How vinyl records are cut: what a cutting engineer actually does.

Why running time, RPM, bass, loudness, stereo width and mastering all affect how your record can be cut.

When audio arrives for a record, the obvious assumption is that I load the files, put a blank on the lathe and press start.

In reality, the cutting itself is only the final part of the process.

Before a stylus ever touches the disc, I have to work out whether the supplied audio, desired format, running time and intended playback level can physically coexist.

Every record is a compromise between length, loudness, bass, stereo information, high-frequency energy, groove spacing and playback reliability.

There is no single setting that works for every record.

That judgement is where much of the work actually happens.

Audio has to become a physical groove

Digital audio can contain almost anything.

A vinyl groove cannot.

When a record is cut, the movement contained in the audio becomes physical movement of the cutting stylus. Loud low frequencies can create large lateral excursions. Stereo information can create vertical movement. Sharp transients and very bright material can demand extremely rapid stylus acceleration.

At the same time, the groove being cut must avoid colliding with the groove beside it. And after all of that, a playback cartridge still has to be able to follow it.

The question is always twofold: can I physically cut this groove — and can a normal cartridge reliably play it back? They are not always the same thing. A groove can have plenty of visible space around it and still be difficult to track.

That distinction has become increasingly important in my own cutting work.

Running time determines how much space there is

A record only has a finite amount of usable surface. A five-minute side and a twenty-minute side therefore cannot be treated in the same way.

The longer the programme, the closer together the groove turns generally have to become. That immediately reduces the amount of physical movement available for the music.

This is why asking “How loud can you cut it?” without also knowing the format, RPM and running time does not really have an answer. A loud, bass-heavy four-minute 12″ at 45 RPM is a completely different engineering problem from a seven-minute 7″ at 33⅓ RPM. The same master may behave very differently on each.

33⅓ RPM versus 45 RPM

RPM also changes the problem. Where running time permits it, 45 RPM can offer advantages, particularly for demanding high-frequency material and DJ-focused releases. But 45 RPM consumes considerably more groove length for the same programme duration.

If the music is too long, 33⅓ may become necessary simply to make the side physically fit. That is another compromise: more generous playback conditions versus available playing time. There is no universally better choice. The correct choice depends on the record.

Loudness costs groove space

Making a record louder is not simply a case of turning up a gain control. More cutter drive means more groove modulation. More groove modulation means the groove needs more room. At some point the walls of adjacent turns can become too close, touch, or become physically unsafe.

That means a long side may need to be cut quieter than a short one, even when both arrive at exactly the same digital loudness. Sometimes this surprises clients because the digital master itself may look perfectly healthy.

But digital headroom and physical groove headroom are two different things. A file being below 0 dBFS does not automatically mean it can be cut loudly onto a record.

Bass is particularly expensive

Low frequencies create some of the largest groove movements. A sustained bass note around 40 or 60 Hz can require substantially more physical excursion than much of the rest of the music.

That does not mean vinyl needs to sound thin. Far from it. It means the bass has to be controlled intelligently.

I look at where the real low-frequency energy is occurring, how wide it is in stereo, how sustained it is, and whether a specific event is likely to become the limiting point of the entire side. Sometimes nothing needs changing. Sometimes one short bass event prevents the rest of the record being cut at the desired level.

The correct response is not necessarily to remove bass from the whole record. It may be to deal with that one event. Local problems should have local solutions wherever possible.

Stereo bass creates another challenge

Vinyl stereo is created through a combination of lateral and vertical stylus movement. Very wide low-frequency information can therefore create substantial vertical movement in the groove. Unusually strong low-frequency stereo information can become mechanically difficult, even when the overall level of the track is reasonable.

I therefore look not only at how much bass there is, but at what that bass is doing geometrically. That is one reason a master designed purely for digital playback does not always translate directly to vinyl.

Bright masters and sibilance

At the opposite end of the spectrum, very bright material presents a different problem. Hi-hats, cymbals, distorted synths, sharp percussion and vocal sibilance can force the cutter to move extremely quickly. The issue is not necessarily conventional clipping. The problem can be acceleration.

A record can appear to have perfectly adequate groove spacing while a particular burst of high-frequency information still creates rough groove walls, distortion or playback mistracking.

Vocals are a common example. A heavily compressed or poorly recorded vocal may already contain aggressive S and SH sounds. Cutting it onto vinyl does not magically remove them.

The important job is determining whether what I hear is already present in the source, or being introduced by the physical cutting process. Those require completely different solutions. Removing source sibilance unnecessarily can dull a recording. Ignoring genuine cutter breakup can produce an unpleasant record. The distinction has to be made by listening and testing.

Transients can be difficult even when the groove looks fine

One of the more interesting things I've learned through repeated physical testing is that groove clearance alone does not guarantee trackability. Rapid repetitive transients — hats, rides, percussion, sharp electronic material — can sometimes create tracking problems even when there is visible land between the grooves.

That means an engineer cannot judge a record purely from a waveform or even purely from looking through a microscope. The playback cartridge is part of the system too. This is why my process combines measurement with actual test cuts and playback.

The inner groove matters

The physical conditions change as the stylus travels toward the centre of a record. The same amount of audio is being represented over a smaller circumference. High-frequency material can therefore become more demanding toward the inside of a side.

Track sequencing can matter because of this. Where possible, extremely bright or aggressive tracks are often happier further toward the outside of a record, while gentler material may tolerate the inner area better.

Sometimes clients have artistic reasons for a particular sequence, and that is completely valid. My job is then to understand the compromise and make the best possible cut within it.

Mastering level is not the same as cutting level

A common misconception is that a louder digital master will produce a louder record. Often the opposite can happen. A very heavily limited master may contain dense sustained energy that leaves the cutter with less room to operate. A slightly more dynamic master can sometimes be cut more effectively because the groove has space to breathe between peaks.

There is no magic LUFS value that makes something “vinyl ready”. I look at the actual programme. Frequency balance, dynamics, stereo behaviour, transients and duration all matter together.

Sometimes the right decision is to make the record quieter

This is probably one of the most important parts of professional cutting. The engineer has to know when not to chase level. A few extra decibels are worthless if the result is groove collision, distortion, excessive cutter stress or a record that skips on playback.

Sometimes the best version of a record is slightly quieter and considerably cleaner. That is especially true with long sides, small formats and difficult source material. The goal is not to make a meter read as high as possible. The goal is to make a record that sounds good and plays reliably.

Sometimes the master itself needs work

Not every problem should be solved at the lathe. If a particular frequency, transient or stereo event is making the record difficult to cut, I first determine whether a small, transparent correction can solve it without changing the character of the music. Where possible I favour targeted adjustments rather than broad processing.

But there is also a point where the correct professional decision is to stop. If a supplied master would require substantial corrective work, the better option may be to ask the artist or mastering engineer for a revised version. That preserves both the music and the role of the original mastering engineer. It is also why supplying a master specifically prepared with vinyl in mind can make such a difference.

Why I make test cuts

My analyser and measurement system can tell me a great deal about a side before it is cut. But numbers do not outrank the physical record.

For challenging material I identify the sections most likely to expose problems, including things such as:

• low-frequency groove excursion
• high-frequency wall texture
• stereo or vertical movement
• rapid transient tracking
• demanding inner-groove material

I then physically cut and inspect those sections. If there is a problem, I change one variable at a time and repeat the exact same passage. That tells me whether the issue is genuinely being solved rather than simply moved somewhere else. Only the physical test tells me what the system actually did.

A test section passing does not mean the record is finished

Another distinction that matters is the difference between a test passing and a record being proven. A difficult eight-second section cutting cleanly is useful evidence. But a complete side still needs to be cut. And then that side needs to be played all the way through. Only then do I know that the complete combination of programme, groove spacing, drive level and physical setup works together.

For a production run I want repeatability too. The goal is not simply: “I managed to cut it once.” The goal is a process that can reliably produce the rest of the order.

The compromises are interconnected

This is the part that is difficult to explain with a simple price list.

There is no single knob
marked VINYL.

The job is finding the point where all of those variables coexist successfully.

What you are paying a cutting engineer for

The value is not simply access to a lathe. It is the judgement required to decide what can be left untouched, what genuinely needs intervention, where the physical limit actually is, and which compromise causes the least damage to the music.

Good cutting should often be invisible. Ideally, the artist does not hear a collection of technical decisions. They simply hear their music coming back from a record in a way that feels right.

That is what I am trying to achieve with every record cut here. Short-run records are still records. Whether it is one copy or fifty, the same physical laws apply. They deserve the same level of care.