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Avoiding Mr. Murphy: Getting It Right In The First Place

Under the principle of "everything that can go wrong..."

I’ve heard it said many times, in many different situations, that we tend to think we don’t have time to do something right, but then somehow, have time to fix everything that goes wrong as a result.

We all know Mr. Murphy and his law about things tending to go wrong if there is any possibility for them to do so. But what can we do about it?

For starters, correct that first part – the thing about making sure things are set up and tested before they need to be used. If there isn’t time, somehow we still have to make time.

Here are some classic examples drawn from many years of personal experience, in rough order of how they fit into a typical job.

1) Is the rider current? Sometimes it’s a miracle to get the darned thing in the first place. Nevertheless, it’s in our best interest to talk to someone, hopefully a knowledgeable person with the band, about how accurate or correct the rider is that we have in our hot little hand.

Murphy: If you don’t check, it will turn out that the rider is three years old and everything important has changed.

2) Who’s in charge of the local crew? If you’re not sure, it’s easy to assume that the guy acting like the boss is the boss. On a job, just like the military, the chain of command is important to recognize and respect.

Murphy: The guy to whom we’re giving important instructions is just a low-level crew person and won’t pass along critical bits to the other guys. Meanwhile, the actual boss gets ticked off.

3) Is the power and grounding adequate and correct?
I keep one of those little yellow plastic AC power testers in my bag for a quick check before I plug anything in. This is a start, but it’s also a good idea to have a conversation with someone in the venue that knows about the house power. Still, check it yourself. The more we know about power, the better.

Murphy: If we don’t check it, hot and neutral will be reversed, or there won’t be a good solid ground. Either way, equipment might be destroyed or far worse, someone might die.

4) What is the condition of the XLR cables? This is something that if we’re not checking regularly, we should be. All manner of things can go wrong: intermittent connection due to fraying wires or fatigued solder joints; one leg can be dropped so the cable passes audio but sounds like ass; polarity can be reversed; etc.

Murphy: If we don’t check the cables regularly and before the gig, embarrassing moments in audio history can result.

5) Are all loudspeaker cabinets and/or drivers in the correct phase/polarity? Ever notice that a particular cabinet just doesn’t sound right, but all drivers seem to be working, sound comes out, etc? It’s possible one of the drivers is hooked up with the wires reversed. Or, the cable isn’t wired right so one of the cabinets is out of polarity altogether.

Getting used to this sound and the reason for it can speed up your troubleshooting.

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Murphy: The sound won’t be right, but the reason won’t be obvious.

6) Will there be video production, and do they need audio? I can’t tell you how many times I’ve shown up to a job unaware of the fact that the “vidiots” will be there. Inevitably, someone will approach me asking for an audio feed.

Fortunately, years ago I put together an “everything adapter” kit, including a passive DI, so that I could isolate my system from the video stuff and avoid ground loops.

It goes beyond that, though. A “board mix” usually doesn’t sound so hot, and it’s difficult to explain to non-audio pros. We might be better off to have a pair of mics at front of house, and a stereo delay strapped across our “board mix” so we can provide a semi-decent mix to the video dude.

Murphy: If we’re not prepared for the video stuff and hooking up to it, we’ll get ground loops and provide a crappy mix that will be blamed right back on us. Same goes for audio recording.

7) Immediately prior to a show, are there fresh batteries in the wireless microphones? Along those lines, have we re-checked our frequencies, antenna connections and gain structure?

Murphy: The batteries will die right in the middle of the big musical number or the CEO’s speech. That is, if the wireless mic works in the first place. If the gain structure turned out to be set wrong, we’ll either have too little level, distortion, or howling feedback.

8) Are the direct boxes connected properly and the ground lift set correctly for the source? Further, are we using the best DI boxes we can given the situation? If they’re battery powered, do they need a fresh battery? If they’re phantom powered, is phantom turned on at the console?

Murphy: There’s bad audio, no audio, ground loops and frustrated musicians and techs as everyone scrambles to figure out what’s going on.

9) Is everyone aware of the proper turn-on and turn-off sequence for the equipment? Power amplifiers on last/off first is the simple way to handle it. But if you really want to be careful, when turning things on, it’s a good idea to start at the console, then work your way towards the loudspeaker.

Work backwards from the loudspeakers when turning things off. This minimizes the pops and surges sent down the wires to the next device.

Murphy: If anything is turned on while the power amplifiers are already on, there could be an expensive, driver-blowing “pop.”

10) Is the console gain structure set within reason before any audio is passed to the loudspeakers? If we have total control over our entire system (rare, but possible) this may be less of a concern. Nevertheless, things get bumped, buttons get pushed, knobs get turned.

Murphy: If we haven’t checked every channel, there will be the one that is set wrong, causing deafening feedback and/or loudspeaker damage.

Doubtless you have your own list in addition to what I’ve presented.

Karl Winkler serves as vice president of sales/service at Lectrosonics and has worked in professional audio for more than 25 years.

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