One of the largest problems facing many live groups, playing or recording, is that of the monitor system. We have to deal with high level output from the speakers getting back into the sensitive microphones causing feedback headaches. If you apply the science correctly, though, high-level and high-quality monitors CAN be easily maintained for all of your performances.
Here are a few tips that I think can help. . . .
- Refrain from using larger diameter speakers. A pair of high-quality 10" with a 1" midrange driver on a 40 or 60 degree horn works best.
- Choose a dynamic microphone with a tight cardioid pattern.
- Place the monitor in the null of that cardioid pattern . . . directly BEHIND the mic and aimed a bit lower than the mic element.
- For floor monitors, use larger sorbothane shock mount rubber feet to decouple the stage.
- For side fills, it is best to elevate them about ear level and aim a bit BEHIND your head so the path is not directly into the microphone.
- Side fill monitors that are 15' to 20' left and right will give you a bit of a time delay, thus reducing some of your feedback path. The combination of front and side fills is terrific.
- Keep the sensitivity of the microphone as low as possible. The input gain of that first stage in the mixer is vital. If you can keep that –3 to 4dB down from where you normally use it, your feedback path will be reduced and it is easier to tame the monitors.
- Use parametric equalizers. It is so easy to null feedback carriers with a parametric. Run the monitors up to a feedback tone . . . a steady tone. Narrow the bandwidth and slowly turn the null control until that tone is gone. Parametric is a wonderful tool.
- Keep unused microphones closed. Every time you open a microphone channel you have to reduce your system output by –3dB . . . open ONLY the microphones that are in use for a particular passage. VERY important.
- Wire your monitors OUT OF PHASE. Reverse the speaker leads so they are out of phase with the microphones. It is one of the best live sound tool sounds around.