Miles Showell Interview – Half Speed Mastering at Abbey Road Studios

Miles Showell In-studio

Universal has just released six classic albums which have been through a half-speed mastering process at Abbey Road. MusicTech speaks to Miles Showell, the engineer behind the process, about his setup and why half speed is better than full…

Miles Showell In-studio

Abbey Road is certainly maintaining its status as one of the world’s busiest studios at the moment. As well as being ‘that’ iconic recording studio, it is the place to record film soundtracks, and has now become a centre of mastering excellence with a half-speed mastering service recently used on six famous albums from the Universal back catalogue, including The Rolling Stones’ Exile On Main Street; Ghost In The Machine by The Police and Simple Minds’ New Gold Dream. The remastered albums are available as limited editions, pressed on 180g vinyl, and with ‘deluxe packaging that includes a certificate of authenticity from Abbey Road’.

Half-speed mastering is a process that aims for ‘a superior listening experience with a new level of depth and clarity’, via superior high-frequency response and very solid and stable stereo images.

The mastering engineer behind this process is Miles Showell, who has worked in the area of mastering or post production since 1984, where he started as a junior engineer at Utopia Studios in Primrose Hill: “making countless cups of tea and coffee and in charge of making export analogue-tape copies of production masters and the running of tens of thousands of cassettes.” He worked there for five years before being “let loose on the Neumann disc-cutting lathe un-supervised”. From there, he moved to Copymasters/Masterpiece in 1989, then Metropolis in 1998, before joining the team at Abbey Road in 2013.


Miles has worked on a huge and diverse catalogue of recordings, including music by Dido, Iggy Azalea, CeeLo Green, Above & Beyond, Ed Sheeran, The Beatles, Disclosure, Phil Collins, Andy Burrows, George Michael, The Rolling Stones, ZHU, Underworld and Sophie Ellis-Bextor. Here, he talks exclusively to MusicTech about half-speed mastering and its use on the new album releases.

MusicTech: Hello Miles, so tell us a little about the set up you have for mastering at Abbey Road…

Miles Showell: The main components in my mastering room (aside from my ears) are the PMC MB2 XBD monitors. PMC build truly fabulous monitors, which give incredible detail and are accurate even at low listening levels. Other equipment includes equalisers from Sontec (432C), Manley (Massive Passive Mastering Edition), Maselec (MEA-2), EMI (TG 12410) and Dangerous Music (BAX EQ). For compression and limiting, I have access to Shadow Hills Industries (Mastering Edition) dual optical/discrete compressor, as well as Maselec and Elysia.

All of the analogue equipment in the chain can be used in either sum and difference (middle and side) or linear stereo modes. Pretty much everything has click-stop pots, which allow accurate re-setting. The digital workstation I use is a SADiE version 6 and the converters are from Benchmark.

All the digital equipment in the chain is locked down with very stable external word-clock generators and connected together via an in-house designed and built proprietary digital patch system. The sole reason for choosing the equipment is for the ultimate transparency and sound quality. Build quality is also of paramount importance, it is no good having the sound of a particular piece of gear drifting day by day. In mastering, you need absolute stability and repeatability.

Miles Showell 2

And the winner of this month’s Show off your Studio award is… Miles Showell. All glory to the monolithic PMC MB2 XBD monitors which Miles describes as “truly fabulous” with “incredible detail”

MT: Can you tell us a little about the mastering process within a typical job?

MS: No two jobs are the same, but the most important part of mastering is to listen to what is there in the recording. It’s all too easy to dive straight in and start fiddling with it without hearing how a mix will develop and change over the length of the track.

Until I know what is going to happen in a particular song, I can’t really make an authoritative decision on what should or, equally importantly, should not be done. However, I’m of the school of thought that less is more. Despite having access to some of the very best gear ever produced, running a recording through an equaliser or a compressor will have a bearing on the sound.

It’s important to gauge whether the gain I’ll get from adding, for example, some EQ to a track is worth the loss imposed by putting said EQ into the signal path. Some mixes I get are fabulous and need nothing adding or taking away; in these cases, the best thing I can do is be brave and admit there’s nothing I can bring to the party, just because I can screw in lots of EQ, it doesn’t mean I should.

However, this isn’t always the case – very often, I get mixes sent to me that are not mixed in the most ideal environment or on the most ideal equipment. This is what mastering is for: to resolve any issues that may have cropped up somewhere along the line.

MT: Tell us about half-speed mastering – how does it differ?

MS: Half-speed mastering is a vinyl-cutting process where both the source is played out and the cutting lathe is running at half the real-time rate (effectively the source and the disc cutting lathe are locked together, but both are running at precisely half the correct speed). The advantage of this is the system is not stressed.

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. 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 (treble) and very solid and stable stereo images.

Remember, the only way a pressing plant can press a really high-quality record is if the process starts with a really high-quality cut. Unfortunately, however, it’s not as simple as running everything at half rate. There is an EQ curve (RIAA) applied to all vinyl records and by running the lathe at half speed, all the frequencies are wrong.

Abbey Road have installed custom designed and built RIAA filters into the cutting amplifiers that feed the modified VMS 80 lathe. These custom filters apply the correct EQ curve when cutting at half-speed.

MT: How did your relationship with Universal Records begin, and why did they choose the half-speed mastering route?

MS: Universal own Abbey Road, as it was one of the assets they acquired when they bought EMI. I am freelance here, but shortly after starting, I was able to persuade the management that half-speed mastering was worth the investment.

Initial feedback from my early clients was so good that it was the management who approached Universal and said, “you have a fabulous library of recordings and we have a world expert on half-speed mastering in the team. There is resurgence in vinyl sales and a demand for good-quality pressings.

Therefore, why do we not get together and create the highest quality vinyl records possible, by pooling our resources and playing to all of our strengths?” Universal thought it was an excellent idea and here we are, with the first six albums in this series just released.

MT: What were your specific goals with these masters? Did anything stand out that needed dealing with initially?

MS: My goal was to transfer as faithfully as possible these recordings to disc. In this series, I was able to master all-but-one of the albums (the Rolling Stones being the exception, they own their recordings and they have complete control on how their music is presented).

I used the less-is-more approach as mentioned above and absolutely avoided all digital limiting, as this is the death of good sound and totally unnecessary for vinyl records.

MT: We’re guessing each album gave you a different set of challenges…

MS: One of the problems I had with on one of the recordings was where the master tape had been damaged by being played at some point in its history on a tape machine that had not been de-magnetised correctly. This had caused damage to the tape in the form of random, very loud clicks, rendering it unusable. However, as I was working with a high-resolution digital transfer, I was able to remove these clicks using a digital-restoration tool while leaving the surrounding audio intact by making hundreds of tiny edits.

Only the clicks were treated, as if I were to pass the entire track through a de-clicker, it would have had the unwanted side effect of softening the impact of the drums and sucking the ‘air’ out of the recording.

My method is extremely time consuming, but produces the very best result – which was the point of this series of albums. Another problem would be the well-known one of persuading 1970s and 80s vintage analogue tape to play! However, this can be temporarily resolved by baking the tapes at low temperature in a special incubator for 24 to 36 hours. Abbey Road has two incubators in the building and plenty of experience at baking tape.

Miles Showell Imparts Wisdom

MusicTech: What advice would you give anyone entering the world of mastering, or indeed the recording industry as a whole, wanting to make a decent living?

Miles Showell: In the current climate, it’s very difficult. But if you are determined, my advice would be: trust what your ears and gut feeling are telling you. When it all boils down, this is all any of us really have.

MT: What advice would you give to our readers on mastering their own music? Is there any process they can apply that will help; any simple tricks that they can use?

MS: Not really, apart from trusting your ears. The big problem with home mastering is the monitors. It’s difficult to know what needs doing to a mix if you aren’t hearing it accurately. There are many semi-professional monitors that are coloured to make everything sound nice.

This really is not a lot of good for mastering as, if there is an issue, I need to hear it so I can get it there and do my best to solve it. My PMCs can be incredibly cruel and expose a problem if it is there – however, the upside is that if a mix is wonderful, I can hear it in all its detail.

MT: What was the most challenging process?

MS: 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 (vocal distortion on the record). None of the tools I would ordinarily use for de-essing work at half speed, so I need to pre-treat everything by capturing all the audio at high-resolution digital, then treating every “sss” or “t” sound in every vocal on every song before progressing.

Because I wanted these cuts to be as good as possible, I used a similar process to the click removal already mentioned. It would have been easy to slap a de-esser across the signal path when making the high-resolution transfer, but the de-esser would not be able to differentiate between a bright vocal or a snare drum, hi-hat, bright guitar, tambourine and other high-energy sounds that don’t require any reduction.

Again, my method is slow and time consuming, but only treats the offending vocal problems and leaves the rest of the music untouched.

Miles Howell at work

Miles using the half-speed lathe. Half speed mastering requires a custom approach to EQ, and specific techniques for processes such as de-essing

MT: Was there ever a time where you couldn’t improve the sound i.e. was it good enough to start with?

MS: In this half-speed series for Universal, the best-sounding album for me was John Martyn’s Solid Air. The tapes were in fabulous condition and they sounded divine. I barely did anything to the sound. Most of the tracks on this album were pretty much a flat transfer straight from the Dolby A decoder to the ADC feeding the workstation. Another great-sounding album was Simple Minds’ New Gold Dream – the half-inch masters were lovely sounding.

MT: What have you got planned for the future at Abbey Road?

MS: This is pretty difficult to answer, as most upcoming projects have carefully planned marketing campaigns attached to them and I run the risk of letting the cat out of the bag by discussing them! However, I can tell you I have recently completed the mastering for the new album by Gallant and he is unbelievably good.

He has an amazing dynamic range and always seems to know when to hold back and when to let it go. He also has a searing falsetto that would put Prince to shame.

MT: Finally, what is the future of music production in less than 100 words?

MS: If only I knew the answer to that question, I would design a super-sophisticated plug-in and sell it for millions to Avid!

MusicTech: How would you describe mastering, compared to the mixing or production process?

Miles Showell: 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.

MT: What is the biggest mistake that mix engineers typically make before submitting their work for mastering?

MS: Mixers often feel the need to make their mix loud so it competes with other already mastered tracks. This is often driven by requests by record company people and/or management, who may be scared that their artist is not loud enough. In reality, a great mix should not be pumped to the max, but be allowed to breathe.

The only way to achieve really hot levels is with extreme compression and limiting. The problem is that compression is something that cannot be undone. If there has been some weird EQ put on a track, to some extent I can un-EQ it, but once a mix has been squashed and ‘pumped’, it cannot be undone.

My advice would be do a pumped version by all means, but don’t make this the master, always run a clean mix using as much mix-bus compression as is needed to make it feel good, but without the extra limiting to get it to compete with already mastered material. Then send both the clean and ‘pumped’ versions to mastering, as it is good to know what everyone is used to hearing. In most cases, I can match or even beat the ‘pumped’ level, but get there cleaner and more transparently.

Miles, happy in his technological playground

MT: Conversely, is there anything they can do to a mix to benefit the mastering process later?

MS: Aside from avoiding compression and limiting as I mentioned before, I would advise that the low end be kept in the middle of the mix. For vinyl work, stereo bass is a big no-no, as the cutting stylus tries to cut in four directions at the same time and ends up lifting out of the disc.

Even if the track is never going to go near vinyl, stereo bass is not a nice sensation for the listener, particularly if the listener is wearing headphones. Try it yourself – do a track with super-wide bass, then put on some headphones and go for a walk. You will probably feel sea sick pretty quickly.