In-ear monitors (IEMs) have replaced wedge monitors for almost every professional touring act in the last 20 years. The benefits are obvious: no stage volume, no feedback, perfect isolation, and a unique mix for each musician. The drawbacks are subtle and often unknown to mix engineers who came up on wedges: IEMs sound dramatically different from wedges, and a wedge mix that worked perfectly on stage will feel claustrophobic and disconnected through IEMs. This guide covers the principles that make IEM mixing different.
The fundamental difference: isolation. Wedges leak the band's on-stage sound into the singer's ears constantly. IEMs block that natural ambience. The result: a singer who used to mix themselves with the natural stage ambience suddenly hears only what is in the IEM mix. If the IEM mix is missing something, the singer hears it as a void — and they will sing or play uncomfortably as a result.
The ambience problem. The fix for the isolation issue is ambient mics: small mics placed on stage (often at the front of the stage, pointing back toward the band) that capture the natural sound of the band and the audience. These mics are sent to every musician's IEM mix at low level (-15 to -20 dB below the main mix elements). Result: the musicians hear themselves and the band in their IEMs, plus a sense of where they actually are on stage.
Ambient mics also capture audience response. The applause, the singalong, the audience shouting — all of which used to come naturally through wedge bleed — now needs to be captured by the ambient mics and sent to the IEM mix. Without ambient mics, in-ear monitoring feels emotionally disconnected from the room, and musicians often perform less expressively as a result.
IEM mixes are personal, not FOH. Every musician's IEM mix should be optimized for their specific role on stage. The drummer needs to hear the click track loudly, the bass clearly, and the snare and kick less prominently than other elements (they're hitting them — they don't need them in the mix). The lead singer needs their own vocal loud, harmonies present, instrumental backing at low level, and sometimes a little crowd. The bass player needs the kick prominent for groove lock and their own bass at moderate level.
Click tracks and cues. Modern productions often have click tracks (metronome) and cue tracks (verbal callouts of section changes) sent to the drummer's IEM mix and sometimes to others. These need to be discrete-sounding, loud enough to be unmissable, but not so loud they overpower the music. A common approach: mute the click during sections where the band doesn't need it; bring it up during transitions.
Stereo IEM mixing. Most IEMs are stereo. Use that stereo to create separation. Drums panned naturally (kick center, snare slightly off-center, toms across the stereo field, overheads wide). Other instruments panned where they sit in the FOH mix. The musician's own primary instrument (their vocal, their guitar, their bass) usually centered. Stereo separation in IEMs makes mixes feel less crowded and more accurate.
EQ on IEM mixes. Less than you would expect. The IEMs themselves have their own frequency response, and most musicians get used to that response over time. Heavy EQ can make the IEM mix sound unnatural compared to other monitoring they have used. A subtle high-pass at 50 Hz on every channel and a gentle high shelf cut at 12 kHz to tame the brightness of cheap IEMs is usually all that's needed.
Compression on IEM vocals. The lead singer's vocal in their own IEM mix should be compressed slightly more aggressively than in FOH (4:1 ratio, 6 dB reduction). The reason: the singer needs to hear themselves at a constant level, even when they shout or whisper, in order to pitch and time accurately. The audience can deal with dynamics; the singer monitoring themselves can't.
Reverb in IEM mixes is controversial. Most engineers add a small amount of reverb to the lead singer's IEM vocal — it makes the vocal feel more comfortable in the absence of natural room reverb. Some singers prefer dry IEMs (so they can hear pitch issues clearly). Ask the singer what they want.
Common mistakes: mixing IEMs like FOH (the artist will feel uncomfortable), no ambient mics (artists feel disconnected from the room), no stereo separation (the mix feels crowded), too much compression on backing tracks (kills the dynamics that the artist is reacting to), forgetting to send a different mix to every musician (one mix for everyone is wedge thinking, not IEM thinking), making the IEM mix too bright (IEMs are inherently brighter than wedges, so a flat IEM mix often feels too bright to musicians used to wedges).