Check the Obvious by Greg Silsby

On a recent Sunday, I visited a wonderful congregation that was blessed with both musical talent and the gift of hospitality. Unfortunately, the extent of the sound operator’s qualifications was that he worked in the audio department at Wal Mart. When three musicians stepped up to play and sing, all mics were dead. The three ended up on their knees following cables to see if they were plugged in properly. Embarrassingly long moments passed while musicians and technician searched and shrugged. The spirit of the moment was lost in the distraction. Eventually, the sound system mysteriously came back to life when it was noticed that the Master fader was down.

When problems occur, and they will, first check the obvious. It is vital that you learn the signal path within your system. Only then can you quickly trouble-shoot by following the signal flow. When someone speaks into a microphone and you hear nothing from the speaker system, ask: "Where did the signal stop?" Is there AC power to all components? Does the microphone have an On/Off switch? It’s probably off.

Headphones and a PFL Solo button on your console allow you to check for signal just ahead of the channel fader. Make sure the Headphone Level and Solo Level controls are turned up. Still no signal? Check the signal path ahead of that point. Is the Trim (or Gain) adjusted properly? Has a pad or attenuator been engaged? Are you checking the correct channel? All too often a channel appears to be dead because the operator is controlling the wrong channel. If your console has channel meters or signal presence indicators, look for unexpected activity at another channel. Is the mic cable plugged in at both ends? If it is a wireless mic, is the receiver on? Assuming you can’t readily check the transmitter’s power switch or battery, check for a strong signal at the receiver.

If you do hear the signal in Solo, be sure the channel is assigned to the main mix. If the channel has been assigned to one of the submixes, has the sub been assigned to the main output and is the sub fader set properly? Be aware that sometimes routing another signal, such as a tape source, to the Main outputs can result in it replacing all other sources in the mix. Oh yes, and be sure the Master fader is up.

Greg Silsby

Commercial Sound & Broadcast Guy, Mackie Designs, Inc.

Gregs@mackie.com