Monitors are the most feedback-prone part of any live system, because they point directly at performers holding microphones. Getting them right is mostly about restraint: the least level that lets each performer do their job.
Use pre-fader aux sends so monitor levels do not follow the front-of-house mix. Ring out monitors separately from the mains. Put only what each performer genuinely needs in their mix, and resist the volume spiral.
| Performer | Usually needs | Usually does not need |
|---|---|---|
| Lead vocal | Own voice, some instruments | Full band at level |
| Drummer | Vocals, bass, click | Own kit |
| Bass | Kick, own instrument, vocals | Full mix |
| Speaker or presenter | Own microphone only | Anything else |
Pre-fader sends and why they are essential
Monitor sends must be pre-fader. A post-fader send follows the channel fader, so every front-of-house adjustment changes what the performer hears, which is unworkable.
Check whether your mixer's auxes are switchable. Many provide two auxes with the first fixed pre-fader for monitors and the second post-fader for effects.
If you only have post-fader sends available, set the front-of-house balance first and avoid moving faders during the performance.
Placement and the rejection null
Position wedges so the microphone's least sensitive angle points at them. For a cardioid microphone that is directly behind; for a supercardioid it is roughly 125 degrees off axis, meaning two wedges angled to the sides rather than one directly in front.
Getting this geometry right can yield several dB of extra gain before feedback with no equipment change at all.
Keep wedges close to the performer. A closer wedge at lower level is always better than a distant one turned up.
Ringing out monitors independently
Monitors need their own equalisation, because the feedback frequencies on stage differ from those in the room.
Ring out each monitor mix separately with the performer's microphone live and in its normal position. Ringing out with the microphone on a stand at the wrong height gives a result that does not hold.
Three or four narrow cuts per mix is usually sufficient. More than that and the monitor starts sounding hollow.
Managing the stage volume spiral
The classic failure is one performer asking for more, which makes another unable to hear, who also asks for more, until the stage is louder than the audience system.
Break the cycle by asking what should come down rather than what should go up. Removing an instrument from a mix usually solves the problem more effectively than adding level.
Lower stage volume improves the front-of-house mix, reduces feedback risk and protects hearing. It is worth defending.