Half-speed masters are theoretically better than full-speed albums. If the used equipment overcomes sibilance, a lost octave, and elastic lacquer issues you’re left with the upsides. Upsides include higher frequencies, less inner-groove distortion, and greater dynamic response. If you’re willing to pay 10%-100% more for half-masters they’re worth it.

In this article I want to give you the full picture about the up- and downsides of half-speed mastered albums. First I’ll quickly go over what exactly original master recordings and half-speed masters are. Then I’ll go over the advantages and disadvantages with references to the field’s experts.


What Are Original Master Recordings

Original master recordings are the tapes or files containing all the recorded, mixed, and ordered songs of an album. These are then used to make copies from, like the vinyl records you’d find in stores.

Vinyl mastering is cutting a separate master from the original master recording which is used to press the intricate groove shape into the lacquer of vinyl records.

original master tapes

Mastering is different for vinyl because it creates an analogue master by cutting the frequencies from the original master recording into the master disc physically. Where digital mastering would create digital files based on the original master recording.

Johnny Rock from Johnny Rock And Friends explains, “The master is the last step in the creative process. After all the songs have been recorded and mixed you place them in the right order, balance the volumes and tones between the song. And finally create a finished master recording. And from that master you can make copies.

What Is A Half-Speed Master Album

Half-speed mastering is the process of creating half-speed master albums. These records are cut into the vinyl master at half the speed they normally would from the original master recording. This technique offers advantages like higher frequencies, but also disadvantages like losing an octave of information.

half-speed mastering example

To achieve half-speed vinyl mastering the cutting lathe is rotating at half the speed while the original master recording is also playing back at half speed when creating the vinyl master. This introduces extra challenges that complicate the process, but if dealt with correctly also advantages to the end product.

Difference Between Mastering And Production

Mastering and production are two separate roles, but they are complementary. Where mastering is more involved with looking at the bigger picture of the recording, production is more about focussing on the individual components of a mix.

Miles Showell a Mastering and lacquer cutting engineer at Abbey Road Studio explains it perfectly, “Mastering is a very specific and specialised role and requires a different skillset to production and mixing. I need to take a step back and look at the big picture, whereas production requires a very detailed focus on every individual component within a mix. I see production and mastering as separate but complementary roles.

Half-speed Master Advantages

  1. Higher frequencies
  2. Less inner-groove distortion
  3. Overall greater dynamic response

The cutter-head draws somewhere between a quarter to a third of the current from the drive amplifiers than would be required for real-time cutting, and the recording stylus has twice as long to carve the intricate groove into the lacquer master disc.“, explains Miles Showell.

So less current from the amplifiers is required for the cutter-head and the the recording stylus has more time for cutting the grooves. The lower speed of a half-speed mastered will also help with inner-groove distortion during mastering.

Inner-groove distortion is caused by the shorter and compressed wavelengths the closer you get to the records center. This makes it harder for the stylus to track the grooves closer to the center of the vinyl record.

Miles Showell continues, “All the difficult-to-cut high-end frequencies become relatively easy-to-cut mid-range frequencies. This results in cuts that have excellent high-frequency response and very solid and stable stereo images.

This essentially means high-end frequencies are easier to cut into the lacquer leading to improved trebble and a more transparent audio quality.

Have a listen for yourself. Most of the people hear the difference.
– Miles Showell

As long as you don’t have the really cheapest nastiest usb turntable, you’ll be able to hear the difference.
– Miles Showell

Half-speed Master Disadvantages

  1. Sibilance
  2. Lost octave
  3. Elastic lacquer influencing cutting
  4. EQ curve (RIAA)
  5. Higher price

Miles Showell also goes into the issue of sibilance, “The most challenging process by far – as well as the Achilles heel of half-speed mastering – is de-essing, which is often required to avoid sibilance.

Sibilance is a issue for all vinyl recordings. It’s caused by the s-sound in voices which is hard to nail down in analogue. For digital mastering this can more easily be adjusted for, but in analogue you’re pretty much stuck with it.

Most tools that could help with analogue sibilance won’t work at half-speed mastering.

Kevin Gray shares his view on half-speed mastering, “There’s real limitations to half-speed that aren’t there at full-speed. It’s just the opposite in my feeling to what they like you to believe. There’s problems at both ends of the spectrum.”

At the low end you’re losing an octave of information, because you’re forcing everything to go twice as far down in frequency. On the top end there’s certain limitations to vinyl in the playback where you have to take corrective measures to the music to make it play back cleanly on record players at home.“, Kevin Gray continues.

Kevin Gray also mentions the issue of sibilance, “And there’s no provision for doing that at half-speed unless you do it digitally. So if you want to be cutting from analogue you can not get rid of things like vocal sibilance and that sort of things.

sibilance frequency data graph

Finally Kevin Gray describes the issue of the elastic lacquer material which is actually causing more issues at lower cutting speeds, “The other thing that’s wrong with it is, the lacquer is an elastic material and it’s like cutting through butter with a hot knife.”

He continues, “So if you cut the speed it’s cutting at in half, the elastic of the properties of the vinyl are actually working against you, not for you. So you’re kind of like mushing the stuff back and forth out of the way instead of cutting it cleanly, so there’s some issues with that.

Then there’s the issue of EQ curve (RIAA) that’s applied for vinyl recordings that actually cause wrong frequencies at half-speed. This issue can be fixed with building RIAA filters into the cutting amplifiers.

Finally there’s the issue of cost. Generally speaking, half-speed masters have a higher price. This is due to a more complicated and time consuming mastering process. The price increases range from 10% to 100%.


Thanks for reading. I hope I’ve given you the full picture about half-speed masters. This is one of those subjects where you’d probably need to hear it for yourself to make up your own mind.

Check out Kevin Gray and Miles Showell, they know a lot more about this subject, or check out my other educational articles. Feel free to leave a comment as well, I’ll respond as quickly as I can.

Sources

  1. Miles Showell, Mastering and lacquer cutting engineer at Abbey Road Studio
  2. Kevin Gray, Mastering engineer at Cohearent Audio
  3. Johnny Rock, from Johnny Rocks And Friends

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