Mastering the art of studio setup & acoustics management

Finding the monitors that work best for your room and investing in good acoustics are crucial in this demanding market, writes Jim Evans. 

Mastering requires critical listening and – rightly so – has been labelled the crucial gateway between production and consumption. The various approaches to the mastering process have been debated since records began. Developments in the means of delivery – from vinyl to CD to digital downloads – have necessitated changes in the way recordings are mastered, but there remain two vital constants – accurate monitor speakers and the acoustics of the mastering environment.

Before investing not inconsiderable sums in a set of monitors – and they can run up to many thousands of pounds a pair – first get your room right. As well as recording studios and broadcast facilities, acoustician and studio designer Andy Munro has built many mastering rooms and has forthright views on the key elements to consider when setting up a room.

“The first thing is the room format because there are two basic camps when it comes to mastering,” says Munro. “The traditional format is a large free-standing speaker system in a neutral but fairly lively room by current control room standards. I would call this the London-New York standard as that is where it evolved.”

“The other and more common format these days is a dry room with either close-up monitors or a larger soffit-mounted system, which is basically an extrapolation of the West Coast-LA style of control room. The former was intended to represent a hi-fi living room experience, so the speakers were often from that genre, although as things got louder and rap came along the trend moved to larger, less purist systems, hence the second format becoming more prevalent.”

“All monitors worthy of mastering must be essentially neutral in timbre and that rule should be followed without exception. Needless to say it is not,” Munro continues: “The room acoustics totally dominate the low frequency response that is experienced by the mastering engineer. At two metres from a free-standing speaker the LF wave-front is 50sqm and the ear is 0.04sqm so more than 90% of the energy hits the room and then your ears.”

“The ideal mid-frequency reverberation time is nominally 0.25s for mastering, but classical and old school people prefer longer, maybe 0.35s, whereas new school goes for near zero. Each mastering engineer develops a way of working, which sometimes is difficult to rationalise in purely acoustic terms, but I am certain that absolute neutrality is the only way to go.”

Alchemy Mastering recently relocated to new premises in west London. Owner/director Barry Grint has worked in more than a few cutting rooms and mastering suites over the years and, not surprisingly, has a good idea of what’s involved in setting up a room. “There are two types of monitor – active and passive. Active monitors have the amps built in and passive speakers require a separate amp,” explains Grint. “It really is a question of preference, whether to mix and match amp to speaker, or accept the amp in-built.”

“There are many different makes of speakers and amps, because people prefer a different type of sound to each other. For mastering, the speakers must tell the truth. A flattering monitor system will make a large range of songs sound fantastic, even though they may have imperfections. When mastering, those imperfections need to be heard and addressed.”

Why address them if flattering speakers disguise the faults anyway? “Because the engineer cannot predict what the result will be across a range of speakers,” Grint comments. “Identify the issue, manage it, and achieve a more consistent result over a larger range of speakers. One engineer may use speakers that are more punchy in the mids than another, for example, which is perfectly fine provided that engineer has a good understanding of what is being presented to him.”

As to specific marques of speaker, Grint reports: “In Matt Colton’s room he has a pair of ATC SCM150s, which are active. Physically, they are a good size for the room (cabinets) with enough power to deliver a good volume without being over-demanding on the amps. The bass driver can move the air well to deliver an accurate representation of the low frequencies.”

“We are currently trying a range of different monitors in my room to decide what we feel best suits the room. Personally, I don’t believe you can make a hard and fast rule of ‘we only use blah blah monitors’. The room interacts with the monitors – find the speakers that work the best and finesse their positioning to the best result.”

At AIR Mastering, John Webber suggests: “It’s about ensuring that all supplied audio is fully represented with the lowest amount of distortion and coloration. You want a clear and detailed soundstage and not one that is smeared. It’s also important that main monitors are not fatiguing and still sound good at a lower listening level.”

“You must make sure you deliver the truest sonic representation to your monitors as possible. Creating a neutral acoustic is vital. You won’t know how effective any gear is unless you’ve created an excellent listening environment. It sounds simple but we don’t live in an ideal world, the basics in terms of monitoring and acoustics are extremely tricky/expensive to achieve the standards we expect.”

“We’ve taken the top-end hi-fi approach as opposed to the studio monitoring approach. We were very lucky to get Europe’s first set of TAD Reference One loudspeakers. These are biamped with Class-D Tricord research mono blocks. The speakers were tested with different amps and cables before arriving at this combo.”

Abbey Road’s Geoff Pesche has worked in the studio industry for many years, including time at Utopia, Tape One, Masterpiece, and Townhouse Studios. In that time he has built an enviable portfolio. At Tape One, for example, he cut the vinyl lacquers for the best-selling 12in record of all time, New Order’s Blue Monday, and Dire Straits’ platinum-selling Brothers In Arms.

As to choice of monitor systems, Pesche’s priorities are “sonic clarity and performance at both high and low levels”. He adds: “We use B&W Nautilus, because these suit our room characteristics. I also use Yamaha NS10s as near-fields. The three key elements are the stereo image, voicing of the room and the listening position. There’s no point having the best monitors in the world and listening in a shed. Our rooms are all on a floating floor, with baffled acoustic treatment. The monitors are an integral part of any listening room – almost as important as the ears of the engineer.”

Globe Audio Mastering in Bordeaux will shortly celebrate its 15th year in business and co-owner Alexis Bardinet reports that business at his south-west France complex is buoyant. Like others, he stresses the importance of “getting the room right. It’s important to have almost half of the room with absorption,” he explains. “When we first embarked on this project, our major investment – in time and money – was in the acoustics. And 15 years later we have no regrets – it’s one of the reasons we’re in good health in a difficult market.”

“We’re always looking at new technologies – and keeping a lookout for suitable vintage gear. I’ve always been a big fan of Dynaudio and our main monitoring system is an M3 Dynaudio in 5.1 with XTA crossover and Crest amplification.”

Darius van Helfteren honed his mastering skills at Wisseloord Studios before setting up Amsterdam Mastering, where, again, the room acoustics were the key factor. “Basically, the room is an integral part of the system,” he says. “When I listen to a song I have to master, I can decide (in a general way) within a few seconds what I need to do. Because my room isn’t foggy or clouding the issue, it’s letting me hear the music in a very pure way. When you master or mix in a great room with great monitoring, you don’t need to listen to it anywhere else – because you know exactly how it sounds.”

“You can get as technical as you like when setting up speakers, but for me it has to pass the ‘enjoyment’ test first. And that test is: to listen to, say, 20 of your favourite songs – ones that you’ve always considered to have great sound. Do most of them sound ‘right’ to you? Do you like how they sound in terms of frequency response and stereo image? If not, then something needs to be tweaked. This is especially true when calibrating a subwoofer. It’s all very well to do it technically, but do your favourite bass-heavy songs sound ‘right’ to you, with enough weight or thump. Or is there too much? So, once you’ve got that sorted out, then you can start to get into the details and the technical stuff, like applying more room treating or even a room optimisation processor, for example.”

“When I was in the market for new speakers (around 2005) I went to check out all the most popular speakers for mastering at the time – PMC, B&W, Dunlavy, ProAc, etc – and the ones that I felt most comfortable with were B&W Nautilus. I think it’s important that you choose a speaker you like and that fits your taste.”

Eastlake Audio has designed and built recording and mastering studios across the world – and has seen some changes. “As the independent studios emerged a generation ago, totally independent mastering facilities are now established,” states MD David Hawkins. “They generally employ highly specific mastering-related EQ and dynamic control outboard not always found in music recording environments – such as Maselec and others – and use transmission-line-type monitoring loudspeakers such as PMC, which are more biased to ‘forensic rather than visceral’ examination of the recorded material.

Remote Working

“Mastering facilities now both digitally receive from – and digitally return to – their clients the work sent to them. Physical location has become almost irrelevant as client attendance has faded, and this is exemplified by Simon Heywood and Dick Beetham, who each moved central London operations to the west of England and Sussex respectively. The palette of specific mastering requirements also broadened some time ago with iTunes and other developments.”

“In Eastlake Audio’s recent design work for 360 Mastering in Hastings we were required to cater for astonishingly high sub-40Hz LF energy, as well as provide exceptional levels of sound isolation to adjoining properties at all hours of the day and night, as 360 Mastering’s clients are spread over worldwide time-zones.”

At 360, PMC is the preferred monitor system. The UK-based designer/manufacturer’s systems are found in facilities worldwide – its most recent release, the QB1-A, is already installed at Capitol Studios in Los Angeles.

“Our mastering clients are extremely demanding as they look for so many attributes in a monitor, i.e. transparency, defined image placement, high level (when required), and the really tricky one, an identical balance at all levels,” remarks PMC’s Keith Tonge. “Designing a monitor to excel in every region is certainly a challenge but it comes down to having that holistic view of what is required rather than focusing on an individual aspect of performance to the detriment of everything else.”

“Mastering requires an extremely natural, neutral, open balance so it’s vital that the monitors have a very wide, even dispersion so any reflected audio is as close in frequency response to that direct from the drivers. The ear/brain is extremely clever at identifying reflections that differ in response from those direct from the drivers, and when they do vary it makes for an unnatural and fatiguing session.”

“Keeping coloration to an absolute minimum is paramount so we would preclude reflex designs and horn loading, and avoid elements that could create a ‘character’. It’s also essential that all electronics and driver designs are very much audiophile quality with enormous headroom so everything is working well within their limits.”