Miles Showell, a freelance mastering engineer at Abbey Road Studios (pictured), has been using the technique throughout his 30-year career, as discussed in part one.
Rick Smith, one half of Underworld, is himself a fan of half-speed mastering, having first heard it via cuts by Showell. For dubnobasswithmyheadman, a deluxe version of the seminal electronic classic being re-issue for its 20th anniversary, Showell worked from a 48kHz Pro Tools session provided by Smith. “Rick is a very good archivist, and has always kept really good notes and details from studio sessions and live recordings,” Showell explains, “so I was working with the correct original 48kHz DAT mixes copied into Pro Tools, which I then uploaded to a 96kHz SADiE [DAW] running version 6. I listened to the whole album a couple of times to re-familiarise myself with the material, and made mental notes of what tweaks I should look at doing.”
“For the Underworld album, I started with the longest of the four sides,” he explains, “[as] usually the length of the sides dictates the level you can cut at – the shorter the record, the louder you can cut it. Underworld’s music has a lot of bass, which needs space; so if you have level and length and bass, it’s a problem. Thankfully, for this reissue, it was cut as per the original album, as a double: I think the longest side is about 17 minutes – only slightly longer than a 12” single – so I didn’t have to apply any compromises to the signal in order to fit it on.
“After doing a few tests, I then made an acetate, which we insist all clients have if it is a half-speed cut. Once we have client approval, I then do the master lacquers. I cut those and they go off to the factory. In total, I think I was working on the album acetates for about five hours, and then four hours on the cuts. This was in May for the  October release date.”
Other high-profile clients for which Showell has half-speed mastered in 2014 include Queen, for a new box-set of live recordings from the Rainbow Theatre in 1974; Genesis, for a remastered box set of the trio’s later studio albums; and a forthcoming project for Roxy Music.
What advice would Showell give to mix engineers and producers with regards to creating the best master mix for half-speed mastering? “Aim high and use 96kHz or 192kHz if possible, and avoid too much pre-limiting before you get to mastering,” he says. “People often like their music to jump out of the speakers and be pumped, which is fine if you need to play it to impress someone in an A&R department – but for mastering, it is a lot easier to do work if the mix has not been too heavily squashed.
“So, by all means, do a version for the record company as a sort of pumped-up pseudo-master, but then do another one with that all backed off. It gives me more of a free hand.”