Feature: The ‘complicated algorithm’ of great festival sound

The frenetic festival circuit remains a vital revenue generator for many audio suppliers – but with often stringent noise limits and other specific environmental considerations, it is hardly free of challenges. David Davies looks at some of the latest solutions helping PA companies to optimise the festival audio experience.

Incredibly, it’s that time of year again. If you were one of the 175,000 people fortunate enough to secure a Glastonbury ticket, the chances are that the spectre of this event – still the largest greenfield festival in the world – is dominating your summer plans. For everyone else, there is an ever-growing abundance of other festivals to contemplate, ranging from the mainstream mainstays like V and Reading/Leeds, to more ‘boutique’ events such as Green Man in south Wales and Weekend at the Edge of the Lake in Switzerland – many of them held in picturesque surroundings.

But while the artist roster and format of festivals now varies more widely than ever before, the issues facing PA companies remain relatively unchanged. Ensuring accurate and consistent coverage in climactically challenging conditions is likely to be at the top of the list; similarly, much thought must be given to optimising audio for individual stages and minimising spillage between them and beyond the site perimeter. Then there is the perpetual need for audio systems to be quick to set-up and configure, and sufficiently space-sensitive to cope with what may be cramped operating conditions.

In terms of audio delivery itself, these events are often taking place within an increasingly restrictive regulatory environment. Limits of 65dB (generally measured at the perimeter of the festival or the nearest residence) are increasingly ubiquitous, while other regulations – not least the UK’s Control of Noise Regulations, which specify an absolute maximum exposure for staff (inclusive of hearing protection) of 87dB – also need to be taken into account.

The lot of the festival sound supplier may be a rewarding one, then, but it’s hardly wall-to-wall happiness. In which context it seems reasonable to ask what steps manufacturers have been taking to help provide more festival friendly-audio solutions – and in the context of a schedule that often requires sleep-depriving turnarounds, what other tools are being developed that promise to make PA suppliers’ lives that little bit easier.

Sound Affects

The fact that noise problems relating to festivals are now frequently the stuff of non-trade news headlines underlines the extent to which this remains (no pun intended) a live issue. Just look at the lengthy saga of the Hyde Park Festival, where multiple annual events have brought complaints from nearby residents that shows were too loud – and concertgoers that they were nowhere near loud enough.

“The noise issue is a worry,” says Funktion-One founder Tony Andrews with wry understatement. “It is less of a problem in the United States where you have such huge open spaces to work with, and there are fewer people around to be bothered.

“There is a window where it has to be loud enough to be exciting and not too much to crush people, and a good engineer will have a well-developed sense of that. But although with US events you can pretty much go as loud as you want, the reality is that in the UK and [mainland] Europe the limits imposed mean it can be difficult to achieve a satisfying sound.”

Andrews’ well-documented disenchantment with the more traditional festival circuit has increasingly led him towards a cultivation of the dance world, which he deems to have a “less conservative, more open-minded” approach to audio specification. Nonetheless, he is hoping for a broad festival audience for Funktion-One’s forthcoming loudspeaker system, Vero. Previewed in March’s AMI and expected to ship later this year, Vero is a “complete touring system”, comprising Vero speakers, flying system, amplification, and a bespoke design and prediction software package that allows users to optimise array designs for smooth audience coverage and impact.

One specific feature, Geometric Energy Summation (GES), looks set to have a particular resonance with festival sound suppliers. By eliminating the need for “inconvenient and expensive” delay positions up to distances of 1,000ft or more, GES allows “natural tailoring of coverage patterns and sound pressure levels to keep sound focused on the audience, controlling the off-site environmental impact”.

Funktion-One Vero at the Red Rocks Ampitheatre in Colorado. Credit: Ron Lorman

Not surprisingly, many other loudspeaker developers have been dedicating significant amounts of R&D time to keeping more noise on the site, on the audience… in other words precisely where it is needed and nowhere else.

Ruediger Nuernberg is a freelance sound engineer for Electro-Voice and Dynacord, among others. “I think the best PA manufacturers provide a product portfolio, which – thanks to consistent sound and variable dispersion angles – always guarantees homogenous coverage without having too many individual systems within one product range,” says Nuernberg.

In terms of practicalities on-site, “you cannot compensate the extremely important physical distance”, continues Nuernberg. “Of course, you can influence the dispersion in the lows with the according array arrangement. In reality, this will be where the greatest influence will be. With regards to the tops, this however is limited. Towards the rear of the system, you can certainly minimise the sound through appropriate structural measures. But apart from careful planning of the angles of the arrays, you quickly run out of options.”

In terms of specific EV products, the X-Line Advance continues to resonate with festival sound providers, indicates Helmut Seidl from parent company Bosch Communications Systems: “An X-Line Advance system always consists of components like system controllers, DSPs and amping, which are perfectly matching the line array. By using the same core elements the sound engineer has a familiar sound environment he can trust and knows also how the system reacts in different situations, which makes it easier to control.”

Alongside skilled ears, prediction software and highly directive audio tend to make a vital difference to securing satisfying results, according to L-Acoustics’ director of touring, application, Florent Bernard.

“Getting great festival sound is a complicated algorithm that needs to take into account not just the size and configuration of the audience, but the various possible interactions such as festival décor, the number and placement of other stages, and the proximity of neighbours as well as zoning restrictions,” says Bernard. “The challenge demands not just a great system, but a system engineer who knows how to use planning software like [L-Acoustics’] Soundvision in order to design a festival set-up that will walk the fine line between giving strong, quality sound to festival goers, while avoiding polluting other stages or neighbours.”

Extensive directivity control is vital, he says, alluding to the ability of L-Acoustics’ K1 and K2 systems to offer directivity control in both the vertical and horizontal planes. “This finesse is crucial when you need to avoid sending sound to a neighbouring stage or a nearby penthouse apartment,” says Bernard, adding that rental companies who acquire K1 and K2 systems are trained by L-Acoustics on how to configure the systems.

In terms of specific festivals, Bernard points to a number of recent success stories, including the Calling Festival concerts in Clapham, London, in 2014: “This was a festival where many in the industry doubted the event could be successful without breaching the stringent sound restrictions. Another sound provider even pulled out of the event as they felt unable to guarantee meeting the regulations. SSE stepped in and, with solid design and full use of the L-Acoustics K system features, especially an ingenious subwoofer configuration, they were able to deliver 100dBA at FOH while maintaining all off-site levels at regulation, measured by Vanguardia Consulting throughout the event.”

Compact Concert Capture

For many PA companies these days, one central component of making life easier is a dependable and easy-to-configure recording solution. Be it for quick turnaround or more delayed release, a huge number of acts are now keen to have a permanent record of their festival appearances.

Founded by audio industry stalwart Joe Bull, JoeCo has become a perennial choice for live performance capture. “Many PA companies are now looking for a reliable recording solution that takes up minimal rack space, requires little monitoring, and can operate reliably for hours at a time, even in high temperatures,” says Bull. “For these reasons, JoeCo digital and analogue recorders have become a first choice, as primary or backup systems, for recording entire festivals lasting over several days, because they deliver on all counts. Hard drives can simply be changed at the end of each day and material is ready for instant repurposing for broadcast, ‘Live from…’ albums or other applications.”

Above: JoeCo’s Joe Bull

Specific products to have resonated on the festival circuit include the 64-channel BBR64-MADI recorder. “Compatible with all professional MADI-equipped consoles, it provides a straightforward, compact, single-cable ‘plug-in’ solution for capturing sets, without the need to have a computer (with all its associated interfaces and operating system quirks) at FOH. Using an external hard drive – which can be formatted on the BBR itself – also enables bands and production teams to source recording media while on tour if necessary.”

The company has also registered festival outings (with acts including Two Door Cinema Club and Natalie Imbruglia) for its BlackBox Player solution for live performance playback. “BlackBox Player technology has also enabled artists and bands to easily incorporate their backing tracks into their roll-on/roll-off festival performances, triggered either from FOH, or more often from a band member on-stage. JoeCo Players are available with a range of analogue and digital interfaces and can be remotely controlled via iPad, or footswitch,” says Bull.

In terms of live performance capture, the changing economics of the music industry mean that this trend is only bound to intensify. Live recording, notes Bull, is “no longer the preserve of a few mega bands who can afford to take articulated OB trucks to capture their festival performances – it’s important for all performers to be able to offer the live experience to as many fans as possible after the event. Supplementing the DVD or Blu-ray release of a festival performance with well-recorded and professionally remixed sound is good for the bands and good for the professionals operating the PA companies.”

Glasto Glory

The general opinion among many in the industry is that Martin Audio’s MLA (Multi-cellular Loudspeaker Array) system is something of a ‘game-changer’, not least with regard to its directive abilities. James King, director of marketing at Martin Audio, steps forward to explain some of the core design principles: “Acoustic cells housed within each cabinet are independently controlled by their own amplifier and DSP channel, a total of six in each MLA. The user specifies the required sound levels to occur at various points within the venue and beyond the perimeter, and then intelligent software automatically determines the speaker configuration and individual speaker cells within to produce that result.”

The technique has achieved some notable successes, not least at last year’s Glastonbury Festival. “This control allowed system engineer Mark Edwards to specify and execute a 6dB drop off over the 300m-long audience area, with incredibly even frequency response,” says King. “As a result, headliners including Arcade Fire and Metallica could play at 104-105dBA – the first time such high levels had been achieved in the history of Glastonbury as noise limits are really strict.”

As for the aforementioned Hyde Park events, the MLA system is generally felt to have brought about a dramatic improvement. To which end, Jim King from promoter AEG remarked: “Headliners at Hyde Park are now performing at levels well in excess of 100dB, which was unthinkable only two years ago. This has been achieved while maintaining even better control at off-site monitoring location and with consistently lower number of complaints from the community.”

Not Just About Noise…

But specifying audio for festival applications has plenty of other considerations, not least optimising set-up time and the need to accommodate multiple artists, genres and performance styles. Although we have undoubtedly witnessed a certain atomisation of the market lately into genre-specific events, the world’s attention still tends to revolve around the major multi-artist festivals where each new day is just as likely to bring a performance by Adele as one from AC/DC.

“For a PA company looking at the programme of each festival, the greatest issue is to deliver into the set-up a system able to reproduce with the same level of quality all kinds of music – from acoustic to electronic music” says Grégory Dapsanse, executive vice president – R&D, innovation and marketing at APG France.

Ease of configuration and reconfiguration are therefore crucial – factors addressed by APG’s ‘highly modular’ Uniline family, which comprises a high-powered sub, a bass cabinet capable of being flown, a full-range loudspeaker and a dedicated downfill speaker. “This means it is very easy to ‘take out’ a certain element if it is not required for a type of performance, for example, you are unlikely to want the high-powered sub for acoustic-only music like a small jazz group.”

Powersoft X Series amplifiers at the Siemens Arena in Lithuania

Luigi Chelli, sound engineer at Powersoft, neatly encapsulates some of the priorities from an amplification perspective: “Today, more than ever, tight scheduling is unfortunately the way to go. Far-from-optimal sounding venues and/or reduced set-up time can kill your end-results. In order to gain the most from the time left ‘optimisation’ must be the word: optimisation of the load in/load out times, of mains wiring/patching, of PA rigging and tuning.”

Good power-to-size ratio is another must, and in this regard Chelli points to Powersoft’s X8, which “condenses in 2RU a three-phase power distro with auto load-balancing, a fully configurable input/output non-boolean matrix with state of the art DSP, a ‘patch-bay’ made of 16 Dante I/O, 8 AES3 inputs and eight analogue XLR inputs,” as well as an output stage of 8 x 5,200W.

X Series products also acknowledge the burgeoning trend in favour of increasing the granularity of the PA – in other words, separating the stacks of loudspeakers in individually-controllable sub-sections. “Granularity means more discrete amplifier channels, and lots of traditional rack amplifiers would just cause logistical and set-up troubles,” says Chelli. “With multichannel rack devices such as the X Series we overcome these problems: one 4U pre-patched fight-case can drive 16 channels with authority. DSP power with FIR and raised-cosine/asymmetric filtering, controllable in groups and sections, match to drive the system with ease and a high degree of precision.”

More Regulations Ahead?

With noise regulations already having a serious impact on festival audio configurations, the years ahead could bring additional measures – particularly in terms of working time conditions. “Here in Germany it is interesting to see how the regulations might affect working hours in the next years,” comments Nuernberg. “I expect there will be significant changes, which will strongly affect festivals. In the end, there will be two possible scenarios: either there will be multiple-shift operations throughout the whole festival, or the festival opening hours will be shortened so multiple-shift operation won’t be needed.”

Keeping an eye on the changing landscape will therefore continue to be vital for festival organisers and their contractors. In the meantime, it is clear that the latest generation of audio solutions are making it easier to achieve results that satisfy performers, attendees and nearby residents.

David Davies has been writing about professional AV and broadcast for 15 years. He is currently managing editor of Sports Video Group Europe and has been a member of the ISE Daily, IBC Daily and AES Daily teams.