Abbey Road Studios mastering engineer Miles Showell is a major proponent of the technique of ‘half-speed mastering’. He explained all to Simon Duff
The vinyl mastering technique known as ‘half-speed mastering’ does what it says on the run-out groove: the cutting engineer operates the disc-cutting lathe at half-speed. For work on a vinyl LP, the turntable rotates at 16⅔ revolutions per minute (rpm) – half the playing speed of 33⅓rpm – while the source file, be it tape or digital, is played at half the playback speed. When the finished product is played back at the normal speed, the material transferred returns to its original pitch and tempo, of course.
Miles Showell, a freelance mastering engineer at Abbey Road Studios, has been using the technique throughout his 30-year career. He explains: “A big advantage is that it gives the cutter head twice as long to carve the intricate groove that goes on the disc – and that is the tricky part, really. Think of a groove on a record as the sound waves from a loudspeaker recorded as a wavy line…
“So, let’s say you have a tambourine in the track, and that may have a 12kHz component – the stylus has to vibrate 12,000 times a second in order to cut that tambourine sound. So if you half it all, what starts as difficult-to-cut high frequencies becomes fairly easy-to-cut midrange. It just means you get much cleaner sounding records.
“The cutting amplifiers that drive the cutter head use somewhere between a quarter and a third of the current they do in real time. Nothing is getting stressed [as] everything has twice as long to get on there. It just makes amazing sounding records with very precise, clear stereo separation; amazingly clean high frequencies; and a rich, analogue bass. If you are going to cut a record, it is the best way to do it.”
Showell joined Abbey Road in February 2013, bringing with him a vast array of experience from his training at Utopia Studios, then work at Copymasters (later Masterpiece) and Metropolis (for 15 years). One of his most high-profile recent assignments is mastering the 20th anniversary deluxe reissue on vinyl and CD of British electronic pioneers Underworld’s 1994 debut album, dubnobasswithmyheadman.
The signal path available to Showell post-SADiE includes original, custom-made EMI TG 12412 analogue EQs; a Manley Massive Passive valve EQ; a Prism Sound Maselec EQ; an Avalon EQ; and a Shadow Hills Mastering Compressor (pictured) – commissioned for him by Abbey Road when he joined, and consequently the centrepiece of his armoury. Monitor-wise, he uses B&W Nautilus 801s, as well as PMC 228s and LB1s. A customised Neumann VMS 80 lacquer-cutting lathe was used for the four sides of the vinyl cut of the remastered dubnobasswithmyheadman.
(…Concluded on Tuesday)