Sound Fundamentals
Sound in theatre ensures the audience can hear what's happening, enhances the experience with music and effects, and supports the storytelling. Getting it right is both technical and artistic.
The Sound Operator's Role
During shows you:
- Operate the mixing desk
- Manage microphone levels
- Play sound effects and music
- Follow cues from the SM
- React to what's happening live
Before shows you:
- Test all equipment
- Check microphone batteries
- Set levels during sound checks
- Prepare cues and effects
Basic Equipment
Microphones
Handheld mics: Held by performers. Simple. Usually for concerts or cabaret.
Headset/Radio mics: Worn by performers. Transmit wirelessly. Standard for musical theatre.
Area mics: Fixed positions. Pick up general stage sound. Less precise than individual mics.
Choir mics: For group singing. Positioned to capture multiple voices.
The Mixing Desk
Where all audio comes together. You:
- Control levels for each source
- Add EQ (tone adjustment)
- Apply effects if needed
- Route audio to outputs
Speakers
Deliver sound to the audience. Positioned for even coverage. Main speakers (FOH), foldback (on-stage monitors), and sometimes subs for low frequencies.
Effects and Playback
Sound effects, pre-show music, interval music, underscoring—all need to be prepared and cued precisely.
Microphone Basics
Fitting Radio Mics
- Consistent positioning matters
- Secure placement that won't move
- Consider sweat and movement
- Battery life management
- Clear channel assignments
Common Problems
Feedback: That horrible squeal. Caused by mics picking up speaker output. Solution: reduce levels, change mic position, adjust EQ.
Dropouts: Radio interference or battery issues. Solution: check frequencies, fresh batteries, better positioning.
Rustle: Mic rubbing against clothing or hair. Solution: better placement, different tape, performer awareness.
Plosives: Popping on "P" and "B" sounds. Solution: mic positioning, windscreens if possible.
Mixing a Show
Balance
Vocals should sit above the band/music. Not everything needs to be equally loud.
Dynamics
Some moments should be louder than others. Follow the drama.
Reaction
Live mixing means responding to what's actually happening. Stay alert.
Consistency
Each performance should sound similar. Make notes. Develop routine.
Sound Effects
Categories:
- Practical effects: Things that would make sound naturally (doorbells, phone rings)
- Atmospheric effects: Setting the scene (rain, traffic, birds)
- Transition effects: Between scenes (music stings, blackout sounds)
- Underscoring: Mood-enhancing music under dialogue
Sourcing:
- Commercial sound effects libraries
- Recording your own
- Creating digitally
- Music licensing (check rights!)
The Sound Check
Essential process:
- Test all microphones individually
- Set initial levels
- Check for feedback points
- Test playback cues
- Run through problem sections
- Note levels for reference
During Performance
Your focus:
- Follow the cue sheet
- Watch performers, not just the desk
- Listen to the room
- React to problems quickly
- Stay calm under pressure
Common live issues:
- Performer not projecting (raise level carefully)
- Mic dropping out (have backup plan)
- Feedback developing (cut quickly, find cause)
- Wrong cue (recover and move on)
Health and Safety
Hearing protection: Long-term exposure to high volumes damages hearing. Use protection when appropriate.
Electrical safety: Treat equipment with respect. Report damage. Don't attempt repairs you're not qualified for.
Getting Better
- Listen critically to professional productions
- Learn your desk intimately
- Develop your ears (identifying frequencies, problems)
- Build your effects library
- Practise mixing with recordings
Sound is both invisible and utterly essential. When it works well, no one notices. That's the goal.