The EM Poll

The Show Must Go On

Jan 11, 2008 5:01 PM, By Pat Kirtley

           

Trouble, as the lyrics of almost any blues tune will tell you, is a part of life. If you're a performing musician, trouble can take the form of equipment failure that can ruin a show. In an ideal world, all musicians would have an expert tech staff to repair and maintain their gear, but the reality is quite different. Most bands and solo performers, especially during the up-and-coming phase of their career, have to deal with on-the-gig gear troubles themselves. You either get tossed around by fate, or you learn how to face ol' man trouble head-on.

But if the idea of solving onstage equipment trouble conjures up images of complex test equipment and big red Craftsman tool chests, rest easy. Your best problem-solving tool is your brain, and in this article I'll show you how to develop the logical troubleshooting skills necessary to help you quickly diagnose the sources of onstage equipment failures. I'll also describe preventive maintenance measures you can take and offer suggestions for developing contingency plans for working around major gear failure during a performance.

RULE #1 KEEP YOUR COOL WHEN PROBLEMS ARISE

Panic is a common reaction among performers who are faced with equipment failure just before or during a show. Under the grip of panic, time compresses, feet and hands move more slowly, and brain function stumbles to a halt. Performers who panic haven't developed the most essential skill for dealing with equipment emergencies: keeping a cool head. Staying calm, even to the point of seeing the humor in a situation, is a great ability to develop. Getting upset and assigning blame during these crucial moments is just a waste of time. The best approach is to think, “What can I do, right now, to get us back on track?” Your actions will make a difference, if you're the coolheaded one.

It's easier to keep your cool if you've learned to expect random failures and prepare for the worst each time you head out for a gig. Murphy's Law — “anything that can go wrong will go wrong” — is revisited every day, whenever technology is involved. Any expert in live audio can tell you that gear failures are a part of life. Stage techs routinely spend a portion of each working day tracking down and correcting problems. Big venues with full-time engineers are great, but most bands and performers play in a variety of places, many of which don't have a house system. At those times, it's your gig and your equipment, with no audio experts waiting in the wings to help.

RULE #2 DON'T IGNORE THE OBVIOUS

When you get no sound from your mic or instrument, the first thing you should do, before going into any serious troubleshooting routines, is to check the obvious possibilities. Is your volume turned up? Is your cable fully plugged in? Is the switch on the mic turned on? Has the mixer been accidentally left in solo mode or with a channel muted? It's amazing how many problems are the result of “little things” like that and can be easily rectified. Once you've ruled out the obvious, however, it's time to move on to more serious troubleshooting.

RULE #3 CHECK YOUR SIGNAL PATH SYSTEMATICALLY

In order to quickly diagnose gear troubles, you need to use the technique of logical troubleshooting. It allows you to systematically figure out the source of a problem and helps you avoid the wild-goose chases that can occur when you randomly start swapping out cables and components in the hope of making a quick fix.

The idea is to troubleshoot electronic systems using the concept of directional flow. Like the water in rivers and streams, audio signals pass through each electronics unit or cable in a specific direction. Having a mental picture of the signal flow allows you to know what to expect at each point along the way. (For reference, you might even want to draw a diagram of your setup, clearly showing its components and signal flow, and carry it with you.) Working backward from the output to the input of a sound system, you learn to divide the signal path into easily understood sections and to check each section as you go.

FIG. 1: This step-by-step diagram illustrates one approach to logical troubleshooting. The problem in a malfunctioning P.A. is isolated by working backwards from the output.

Here's a hypothetical example. Let's say you have a P.A. that includes a mixer with a mono output feeding a ⅓-octave equalizer. The output of the equalizer is patched into your power amp (which is configured for mono operation) and that feeds the main speaker pair. Here's the problem: you turn on your system at sound check, and when you test your mics, no sound comes out of the main speakers. After glancing at your power indicators to make sure that everything's turned on, ensuring that your components are set correctly, and checking that your cables are properly connected, take the following steps (see Fig. 1). First, connect a signal source (a portable CD player works well for this application) directly to the power amp, thus bypassing everything before it in the chain (the mixer, the equalizer, and the connecting cables). If you hear clear audio from the speakers, you can logically rule out everything from the amp to the speakers as the source of the problem.

Next, reconnect the equalizer's output to the power amp's input and patch your test signal into the equalizer's input. If you still hear clear audio, then you know that everything is okay between the equalizer and the power amp. You can therefore deduce that the problem is with either the mixer (again, make sure its controls are set correctly) or, more likely, with the cable between the mixer and the equalizer. For the sake of this example, we'll assume the cable is the culprit and that swapping that cable with a new one solves the problem.

Admittedly, the above is a simple example, but the step-by-step logic is always consistent. The same technique — working from the output end of the system back toward the input — works for tracking down no signal, weak signal, or distortion, and can be used on instrument rigs as well. (Some technicians troubleshoot from input to output, and some even start in the middle. However, I recommend the output-to-input method because it's simple and easier to understand.)

RULE #4 ROUTINELY INSPECT YOUR GEAR FOR TROUBLE SIGNS

Sometimes big trouble starts small. A loose screw in a microphone housing finally falls out and gets lost. The output jack on a hollow-body guitar loosens, and before you know it, the nut falls off and gets lost, and the jack drops down inside the guitar. A cable looks frayed at the point where it meets the connector. One day it will come apart. Will it happen during a show? By keeping an eye out for the small clues, you can take action early on instead of reacting in horror when it happens just before — or during — your big gig.

Develop a routine of checking over cables, musical instruments, pedals, mics, and rack gear on a regular basis. In bands, everyone can check his or her own gear. The things you look for are usually obvious — loose screws, damaged cables, connectors that don't fit the way they should, and anything that only works intermittently. It's amazing how much more reliably everything seems to function when each little problem gets attention before it becomes a big one.

Preventive maintenance, as it's called in the industrial world, is always easier and less expensive than repairing or replacing equipment. Although some musicians may disdain the idea of becoming mechanics or electro-geeks, one can feel a sense of pride in the simple act of tightening loose fittings, properly coiling and storing cables at the end of the show, or inspecting the back of an equipment rack in search of wiring problems.