17 Aug 2015

Catastrophic Failure. By Jim Morley

‘Catastrophic failure’. It’s the kind of phrase thrown around after an aircraft disaster or a train crash.

It describes how the minor failure of a tiny and seemingly unimportant component or procedure can lead to a major failure that can cause a disaster involving wide scale loss of lives.

So what does this have to do with us tech people? We have no dealings with life and death situations and simply ride faders and push buttons for our living. After all we are just roadies working on shows. We only fly when we want to go on holiday or maybe if we are touring away from home.

The reality is that for us its got nothing to do with flying, but the parallels are just as valid.

Our situation is that we use expensive and technologically advanced cutting edge equipment to deliver a service to our clients. Our clients expect the show to go on no matter what. They pay us money as part of the deal. If the show falls over they have a genuine reason to be disappointed and upset.

It’s not really such a problem for a failure with most pieces of gear. If a microphone dies, you probably have a spare in the case. If a speaker blows you probably wont miss one in an array or a monitor rig. If a lighting fixture fails no one is realistically going to ask for a ticket refund. Cables…. Well they are more like a consumable item in some respects. Just make sure you carry a spare if you have an unusual ‘breed’ in your rig. That way, hopefully if something fails it wont be a showstopper.

If it’s important and the component that fails is a commonly available item, you may be lucky enough to get hold of a replacement before show time. If its not you are in trouble.

An audio mixer is one such single item that is irreplaceable in a PA system. Every input goes into it and every output feeds from it. It is the hub of your audio system and for anyone working with audio, a possible failure within it is the ‘Elephant in the room’ that nobody really wants to think about too much.

Vision switchers or lighting controllers are the same. They are the nerve centers of their respective systems. A failure with these can definitely bring us un-stuck.

Most techies who have been around a while have either experienced this kind of failure personally or heard a story about one. It’s the sort of thing not everyone will talk about as it can make us look pretty bad.

Contemplate this kind of failure for a second longer. It is potentially career ending. At the least you may loose the client. Its the kind of thing some people would call ‘an act of god’.

If it’s a ticketed show somebody may have to refund part or all of the ticket price. From there it gets really messy with potential litigation as everybody ducks for cover and passes the buck. Good luck to you if you think your equipment supplier will share the liability.

Ahhh… Insurance you say, feels like a breath of fresh air…. But that’s another story!

So what can you do to avoid this failure situation? In theory you need a direct replacement to slot straight in. For your audio system this means a mixer ready loaded with the current show – all recalled via automation. All you need to do is swap all the connections across in a methodical manner and you are back in business. This is great if you have the budget to tour two desks including double rental and transport costs.

And I do hope you are regularly saving your show during sound check to an external means to make this a genuine option. Save it only to the device that fails and you are ‘wrong again’.

In days of Analogue or ‘pre digital’, it seemed somehow less likely that we would have a total failure. The way analogue mixers work, the power supply is the only single item of potential failure within a board. An input channel may go down or even an output, but each of these is generally isolated on its own set of circuits or a discrete circuit board. So there were always ways of getting a signal out of the mixer via an unorthodox path if it came down to it, so long as a power supply (or a dual redundant one) were available. Problem solved!

These days however Digital boards have taken on far more than just the mixing responsibilities. They are in some cases dealing with input signal transport from the stage sources across a venue, then the conventional mixing responsibilities including what would have been considered the ‘outboard processing’ in the old days (racks of noise gates and compressors), the digital networking distribution of the resultant signal, time alignment of various speaker arrays, the crossover functions, and in some cases specific speaker amplifier management tasks.

Add to this the possibility of the show being recorded by the mixing desk itself and you have a whole lot of trouble on your hands if you have a failure. The resulting ‘gulf’ that opens when removing a modern digital mixer from a PA system can literally stretch across distance, technologies and time.

The solution is to carry a spare to fill that gap or risk the consequences.

In truth the manufactures are onto this. They know the failure rates and expected product failure times. They build in redundancy and reliability and always have, but still the scenario is real.

There are other failure points in what we do. A stage collapse or power failure is still a show stopping events. Crew problems, transport failures and venue issues could all arrive in your world without notice. There are black holes in many situations and any chain is only as strong as its weakest link.

But before the sky falls in why not look at it another way?

Pack a spare and tell your clients that you do so. You can use it as a selling point to them. It’s a point of difference between you and your competition that can save the day for all of you. It will allow you to serenely parachute to safety while all around you would have crashed and burned in that same situation.

Most clients would gladly pay a bit more for this level of service if they knew the truth of the situation.

Why not make friends with the Elephant in the room and introduce your new pet to the band! After all, who wants to get caught between a rock (band) and a large African Mammal?


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