Feature: Digital consoles on tour1 August 2016
How is the latest generation of digital consoles standing up to life on tour? Phil Ward straps himself in
Lazzaro Jesus, a monitor engineer in Brazil who’s toured with Brazilian singer Ivete Sangalo, happens to recommend Yamaha mixers for his territory with a singular criterion: namely, “if you want to start the show and finish it”. As items on a to-do list go, that’s pretty high up. “Yamaha’s robustness is a main feature in Brazil since our roads are very bumpy,” he adds by way of an explanation. “If the equipment is not built well, everything inside it could fall apart.”
Other than trusting that the rental rolling stock has good suspension, how do the manufacturers ensure the protection of digital circuits on the road? Assuming not everyone builds roads like the Brazilians, there are several details that nevertheless receive the close attention of the mixer makers. “Our touring consoles spend a lot of time in their cases, so making sure they’re designed to travel and be tipped daily is critical,” says DiGiCo MD James Gordon. “We also design with the core electronics in the console frame: you only have to watch a load-out to see the way the 19-inch cases get treated compared to the perceived more expensive console case.”
“Circuit boards themselves are inherently reliable in a touring environment, especially with modern surface-mount technology which uses very low mass components and so resists vibration very well,” adds Andy Brown, senior product manager at Soundcraft-Studer. “The critical things affecting reliability are always the connectors used to connect one internal system to another, or to external parts of the system like stage racks. We rely on our experienced hardware engineers to make the right choice of connector for the job on internal boards, and along with that goes the right mechanical design to make sure that those connectors aren’t put under any stress. Most consoles involving racks use flightcases with built-in rubber shockmounts nowadays, which helps during transportation. We do vibration and environmental tests on every new console design.”
“Fairlight’s approach is to minimise the risk: our FPGA-based design allows vast and complex electronic circuits to be built inside a single chip,” says Fairlight CTO Tino Fibaek. “This in turn means significantly reduced component count, therefore significantly fewer solder joints, with an overall increase in reliability.”
Clearly, components need to be safely housed and the right materials chosen for the chassis and other thick-of-it accoutrements. “We tend to use aluminium in our consoles,” continues Gordon, “for both extrusions and surface panels as these are light, strong and hardwearing. Modern materials mean you achieve a very light and strong console.”
“Standard steel or aluminium in the appropriate thickness,” reveals Brown, “it’s not really that important which – the more important thing is the mechanical design of the chassis and making it rigid enough so that internal parts stay where they should be, and any cooling requirements are taken care of. I’m sure we’d all love to make console chassis out of aircraft-grade titanium or carbon fibre, but this isn’t commercially viable in our industry.”
Andy Cooper is manager, PA application engineering at Yamaha. “Yamaha touring products have a solid steel chassis, often including reinforcement braces, to increase stiffness,” he says. “Optional interface cards are housed in steel cages with many retaining screws to ensure they don’t wobble out of place during turbulent transportation. The weakest point of any system is cables and connections, whether internal or external: reducing the number of internal cables increases reliability.
“Yamaha digital mixers have fewer internal cables than analogue mixers, and this is a big reason why they’re more reliable. Many rental company staff have told me that Yamaha PM5D and PM1D are the most reliable consoles they’ve ever owned, analogue or digital. Yamaha doesn’t use hard-disk drives in its pro audio products, or any similarly fragile moving parts. All new Yamaha pro audio prototypes are subjected to vigorous drop, shake and temperature tests to ensure durability.”
One Yamaha customer in India, Anish Purao (pictured), is the owner of rental company Chakor Sound in Mumbai. “Most parts of India have hot, humid and dusty weather: around 35°C to 45°C, yet we never experience any issues with Yamaha consoles getting hanged or heated up after continuous 24-7 use,” he claims. “However, other brands can start hanging – and processors overheating – after only a short time.”
One option offered on Yamaha’s mid-range consoles – and it comes as standard on the new Rivage PM10 – is a redundant power supply. “This is not to cover for any unreliability of the components,” continues Cooper, “but to offer security against the electricity supply itself in some regions. If the electricity service is unstable, it’s a good idea to have a UPS connected to at least one of the power supplies! Of course the product needs to work with all possible voltage supplies between 110V and 240V. In countries like Brazil, each city might use a different standard to its neighbours…”
“dLive consoles have been designed to deliver the optimal balance between strength and weight, employing higher grade metal on the sides and folded steel at key points for added rigidity,” says Allen & Heath product manager Nicola Beretta. “In fact, our lead mechanical designer on the dLive project used to be a tank commander! Not only does every console, MixRack and expander have dual power supply slots for redundancy, but we’ve also employed the same rugged, hot-swappable PSU design across the range for maximum peace of mind and minimum inventory. Dual redundancy is also built into every audio connection throughout the system.”
‘D’ moans are forever
The received wisdom is that digital anything is more brittle than analogue, as well as harbouring the potential to destroy civilization in one binary swoop. But pro audio is ready…
“The component count in an analogue console is directly proportional to its channel and buss count – a bigger console equals more solder joints,” says Fibaek. “In an FPGA-based assignable digital console the initial component count might start higher, but does not increase significantly as the channel and buss capacity grows. So, statistically, there is less to go wrong in a like-for-like large digital console.”
“I can only speak for DiGiCo,” says Gordon (pictured), “but our single FPGA-designed engine board is extremely reliable as you have very few interconnections and it’s all on a single PCB – so no base boards that can suffer vibrations and joint failure. Analogue consoles have connection and vibration problems where you would lose a channel strip after shipping, and multiple-DSP board consoles have the same interconnection that can be impacted by living life on the road. Fortunately we don’t have those issues with the SD and S series consoles…”
Andy Brown suspects that digital circuitry may need a little more TLC. “I would say that’s true, particularly with the larger, more complex consoles. On the smaller desks, the number of different internal sub-assemblies which need to be interconnected will be minimised for cost and size reasons, and this tends to help reliability as there are fewer connectors. On the more complex high-end consoles, it’s usually necessary to use some kind of card-frame type construction with backplanes in either DSP engines or I/O boxes, and special attention has to be paid during the design and testing to ensure that these parts are built to resist vibration and movement.
“Analogue consoles are inherently more redundant, which means a failure on one channel strip will not usually affect the rest of the console. You can’t necessarily say that about digital, although we do take care to try to emulate that sort of compartmentalisation within card-based DSP engines. Certain cards will handle all the processing for certain channels, so it’s not all spread across one large lump of DSP. This makes the system better able to at least partially withstand a failure.”
“Don’t forget, digital consoles still need preventative hardware maintenance,” points out Dave Kay, director of Liverpool-based full service provider Adlib Audio. “The majority of problems are mechanical, not software-based. They still need stripping down and the screws tightening to get a good earth, the cables checking and optical links regularly tested.”
Rather fittingly, FOH man Eds John (pictured) has just been out with punky pop 30-somethings Busted. Fortunately, his Avid S6L wasn’t. “It doesn’t matter what you’re using with some of the things that happen at gigs, like a pint of beer getting spilled into a desk,” he rues. “Other common problems include the confetti cannon they fire at the end – you really don’t want all that silvery glitter going down into your faders. But the old soldiers like the PM5D just seemed to keep going, and that’s probably why people keep on using them. It’s all in one box: no local rack, no stage rack, and they never seem to fall over.”
As touring and installation markets merge, the tough usage and challenging environments of legend increasingly apply to all the places these consoles may be permanently ensconced. The ‘road’ today can lead anywhere.
“We have consoles all over the world,” confirms Gordon, “and one that springs to mind lives in a metal box on the side of the bay in Singapore. It’s installed there for the Esplanade and they do some amazing shows on the side of the bay. For a console, it doesn’t get much harder than living by the sea in a metal box at high humidity 365 days of the year…”
“We try to design all the products to cope with rugged environments, including connectors and cables,” says Brown. “For example, all the mid-high-end consoles are shipped as standard with ruggedized breakout panels for durability where remote I/O boxes are part of the system. These panels could be added optionally to the lower-priced consoles but it’s often prohibitively expensive to do this, just because that type of connector isn’t cheap.
“Yes, the consoles can mostly be installed anywhere, and the toughest environment is probably any location next to the seaside: salt water in the atmosphere really takes its toll on electronics over the long term, and it’s not common in the audio industry to use totally atmospherically sealed electronics like the military do – much as we would like that!”
Tino Fibaek points to the modular nature of today’s systems as providing greater protection. “By embracing an IP-based audio distribution and processing architecture, customers would be able to deploy a system with many small elements rather than a single monolithic unit,’ he says. “This solution has many advantages, such as no single point of failure, allowance for active standby units and easy replacement should one element fail.”
“Due to the massive feature set in dLive, the desk is perfect for all installation applications,” claims Scott Mason, Allen & Heath’s pro-digital sector specialist. “With the separate MixRack/Surface configuration, there are no heat issues when installing dLive into certain environments. The three sizes offer a wide range of choices, where size is an issue. The flexibility and ease of use make it ideal where more than one operator is involved, or different levels of expertise are apparent.”
So, install or tour, it looks like “everything inside it could fall apart” represents unnecessary pessimism. Even in Brazil…