Side Fill Monitors: Stage-Wide Coverage Systems

Side fill monitors provide ambient stage sound that helps performers hear the overall band mix beyond their personal wedge monitors. Positioned at stage left and right, side fills create a cohesive sonic environment that supplements individual monitoring.

Purpose of Side Fills

Side fills differ from personal monitors in their purpose. While wedges deliver individual mixes to specific performers, side fills provide a general band mix across the entire stage.

Performers moving around stage benefit from consistent sound regardless of position. Side fills ensure musicians hear other instruments even when stepping away from their personal monitors.

The ambient sound from side fills helps performers feel connected to the full band rather than isolated with only their individual mix.

Speaker Selection

Side fills typically use larger speakers than individual wedges to cover wider areas and deliver higher output. 15-inch two-way speakers or dual-12-inch systems are common choices.

QSC KW152, JBL SRX815P, and EV ELX200-15P serve well as side fills. Their higher output and wider dispersion cover stage areas effectively.

Subwoofers added to side fill systems provide bass guitar and kick drum impact across the stage. Musicians feel the low end that smaller monitors cannot reproduce.

Positioning Side Fills

Side fills typically mount on stands or stack on subwoofers at stage left and right, aimed across the stage. The goal is even coverage across performer positions.

Elevation improves coverage over equipment and performers. Raising side fills to head height or higher ensures sound reaches ears rather than backs.

Angling side fills inward creates overlap at center stage. Performers throughout the stage width receive adequate level.

Mix Content

Side fill mixes usually contain a full band mix, emphasizing rhythm section elements that help with timing and feel.

Vocals may be prominent in side fills to help instrumentalists follow song sections and harmonies. Lead vocal in particular helps the band track arrangement.

Side fill content often mirrors the front-of-house mix, though mixed specifically for onstage purposes. Heavy reverb that sounds good in the house may muddy stage sound.

Balancing with Personal Monitors

Side fills supplement rather than replace personal monitors. The relationship between side fill level and wedge level affects overall stage monitoring.

Excessive side fill level makes personal monitor content difficult to distinguish. Performers may request higher wedge levels, escalating overall stage volume.

Conservative side fill levels—enough for ambient awareness but not dominant—preserve the utility of personal mixes while providing stage-wide coverage.

Volume Considerations

Side fill volume contributes to overall stage volume, affecting microphone bleed and front-of-house mix clarity.

The minimum effective level provides awareness without overwhelming. Louder is not automatically better for side fills.

Watching performer reactions helps calibrate level. If performers seem disconnected from the band, side fills may need adjustment.

Stereo vs Mono Side Fills

Stereo side fills maintain left-right separation across the stage. The guitar panned left comes from stage right (audience perspective), creating spatially accurate representation.

Mono side fills simplify setup and operation. Both speakers carry identical content, providing consistent coverage without stereo imaging.

For most applications, mono side fills suffice. Stereo adds complexity without significant practical benefit in the chaotic acoustic environment of a live stage.

Feedback Management

Side fills operate at high levels and cover wide areas, creating feedback potential. Ringing out side fills before adding personal monitors establishes stable system gain.

High-pass filtering side fills reduces low-frequency buildup that can cause rumble or muddy sound without adding feedback protection.

Side fill frequency response affects stage sound character. Cuts in problem frequencies improve clarity and feedback margin.

Integration with In-Ear Systems

Performers using in-ear monitors may still benefit from side fills. The ambient stage sound supplements the isolated in-ear experience.

Some performers prefer in-ears for detail with side fills for feel. The combination provides precise monitoring plus physical connection to the stage sound.

Side fill levels for in-ear users should be lower than for wedge users, providing ambience without competing with or masking the in-ear content.

Side Fills in Small Venues

Not every situation warrants side fills. Small stages where performers stand close together may not need stage-wide coverage systems.

In cramped spaces, side fills may create more problems than they solve—excessive volume, feedback issues, and cluttered stage.

Evaluating whether side fills genuinely improve the situation prevents adding equipment that does not serve the performance.

Practical Setup Tips

Position side fills before sound check and tune them before adding personal monitors. This establishes the stage’s ambient sound floor.

Start with low side fill levels and increase only as needed. Building from quiet prevents starting too loud and reducing from there.

Check side fill coverage by walking the stage, listening for even distribution. Adjust position or angle to address coverage gaps.