Chapter 13: The System Is Down A Simple Guide to Troubleshooting Tech Issues Many churches these days make regular use of modern technologies such as electricity and sound systems/microphones. If that is not you, feel free to skip this chapter. However, if your ministry does make regular use of mics, monitors, cables, sound mixers, etc - this chapter aims to provide you with a basic understanding of how some of these things work together so that when something stops working (and it inevitably will) you won’t be entirely in the dark. Here are some basic trouble-shooting tips to help you when something goes wrong: 1. Stereo Typing (Identifying Cables): The 2 most common audio cables found on stage are: • XLR3 referred to simply as ‘XLR’ is a balanced, low-impedance connection most commonly used for connecting microphones and DI’s (direct boxes) to a sound mixer. • 1/4” TS (Tip, Sleeve) referred to commonly as an ‘instrument cable’ is an unbalanced and shielded cable used for connecting instruments to amplifiers, sound boards or direct boxes. Here are 2 other cables that are easily confused with the 1/4” TS Instrument Cable: • 1/4” Speaker cable’s connector looks identical to the 1/4” TS - but is an unshielded and usually higher-gauge cable used for connecting power amplifiers to speakers/ monitors. Using a speaker cable in place of an instrument cable can cause noise interference and signal quality loss. Using an instrument cable in place of a speaker cable can cause the cable to get hot and/or burn-out/break. • 1/4” TRS (Tip, Ring, Sleeve) provide the same functionality as an XLR cable and is used most often for effects processor sends/returns at the sound board. Using a TRS cable in place of an instrument or speaker cable can create unpredictable results and potential hazards. If an instrument/mic is not working, your first action should be to make sure that all connections are tight - sometimes cables get moved/bumped/etc. Proper use of cables will help reduce technical issues and extend the life of your equipment. 2. DI Why? (Direct Boxes) “DI” (dee-eye) may stand for direct input, direct injection or direct interface - depending on who you ask. It is a device used to connect a high-impedance, line level, unbalanced output signal (usually a 1/4” TS connector) to a low-impedance microphone level balanced input (usually via XLR connector). Some are passive, some are active (have a preamp built in - usually requiring phantom power), some have only in & out, some have in, out & thru, some have ground lift, signal boosting/cutting, etc. There are a variety of options for use in a variety of applications. 3. The In’s & Out’s of Cable Routing Cables connect multiple devices together allowing signal to pass between them. To troubleshoot routing, we must understand the directional flow of signal. Cables carry signal (sound) from one device to another (eg. signal flows from a microphone through a cable to a sound mixer). Think of it as a train that travels through multiple stations before reaching it’s destination - the signal (from your mic/instrument) boards the cable and get’s off at the speakers. Each device in your signal path is a station, the train comes in, the train goes out, the signal goes into a device, then leaves out of that device - into another. Out to in. Out from an instrument In to a DI. Out from the DI In to the mixer/ soundboard. When tracing a problem, start with the source and work toward the end. Here are a few basic signal-flow examples: • Voice > Mic > Mixer > Amp > Speakers > Ears • Guitar > Pedals > Guitar Amp > Mic > Mixer > Amp > Speakers > Ears • Bass > Tuner > DI > Mixer > Speakers > Ears If this sounds over-simplified, that’s because it is - but ‘out to in’ is a concept easily overlooked that will stop a signal in it’s tracks. Understanding the directional flow of signal with help you to strategically eliminate problems as they arise. 4. Sound Off! (Troubleshooting Microphone Problems) • Check that cable is firmly connected (if it is a wired mic) • Make sure the power is turned on (if it has a power switch/button) • If it will not power on, the batteries may need to be replaced • Make sure it is not muted (if it has a mute switch/button) • Try plugging a different mic into your cable to see if the problem is with the mic or something further down the signal path. If replacing the mic doesn’t fix the problem, try replacing the cable and so on. 5. Assault & Batteries Many devices including wireless microphones, guitars with active pickups, guitar pedals, etc depend on the use of batteries and can cause unwanted disruptions when they run out of juice. It is good practice to keep the required batteries in stock so that they will always be available when needed. Some churches use fresh batteries each week or service to eliminate any potential power disruptions. At my church, the sound person is able to monitor microphone battery levels from the back and can replace batteries as needed before they completely go out. This saves waste and dollars - but it requires that the right person has their head in the game. Since the battery in my acoustic does not need to replaced very often, I just keep a fresh 9V handy on stage and replace it when it fails or every couple of months - which ever comes first. To maximize instrument battery life, unplug your active instruments before leaving for the day. Familiarizing yourself with these very basic troubleshooting techniques will hopefully enable you and your team to quickly diagnose and fix technical difficulties when they pop up and keep your rehearsals and worship times running smoothly.