Why This Matters
In stage management, you're not expected to be the audio engineer—but you are expected to understand how sound systems work well enough to troubleshoot problems, communicate effectively with your sound team, and anticipate technical needs during rehearsals and performances. When a mic cuts out mid-show or feedback screams through the house, knowing the signal chain helps you identify where the problem lives and who needs to fix it. You'll be tested on your ability to recognize how these components interact, not just what they're called.
Think of a sound system as a journey: sound enters through input devices, gets shaped and controlled through processing equipment, and exits through output devices. Along the way, signal routing and power management keep everything connected and protected. Don't just memorize a list of gear—understand where each component sits in the signal chain and what problem it solves. That's what separates a stage manager who can lead from one who just watches.
These components capture sound and convert it into electrical signals that the rest of the system can process. The quality of your input determines the ceiling for your entire mix.
Microphones
- Transducers that convert acoustic energy into electrical signals—the first link in your audio chain
- Three main types: dynamic (rugged, handles high SPL), condenser (sensitive, requires phantom power), and ribbon (warm tone, fragile)
- Placement directly affects gain-before-feedback—understanding mic technique helps you anticipate staging needs
DI Boxes (Direct Injection Boxes)
- Convert high-impedance instrument signals to low-impedance mic-level signals—essential for connecting guitars, keyboards, and bass directly to the console
- Eliminate ground loops and reduce noise over long cable runs between stage and front-of-house
- Active DI boxes require power (battery or phantom), while passive DI boxes work without external power
Audio Interfaces
- Bridge between analog sound and digital processing—convert mic and instrument signals into data your DAW can manipulate
- Include built-in preamps that boost weak signals before conversion
- Multiple I/O options allow simultaneous recording of several sources—critical for capturing rehearsals or archiving performances
Compare: Microphones vs. DI Boxes—both are input devices, but microphones capture acoustic sound while DI boxes accept electrical signals directly from instruments. If an actor's acoustic guitar sounds thin, check the mic; if the keyboard is buzzing, look at the DI box.
Signal Processing: Shaping the Sound
Once audio enters the system, processing equipment shapes its tone, dynamics, and spatial characteristics. This is where raw sound becomes polished audio.
Mixing Console
- Central command center for routing, balancing, and processing all audio signals
- Controls include gain, EQ, aux sends, panning, and faders—each channel represents one input source
- Analog consoles offer tactile control; digital consoles provide recall, effects processing, and flexible routing
Equalizers
- Adjust frequency response to boost or cut specific ranges—making vocals cut through or reducing room rumble
- Graphic EQs use fixed frequency bands with sliders; parametric EQs offer adjustable frequency, gain, and bandwidth
- Room tuning uses EQ to compensate for venue acoustics—a boomy theater might need cuts around 200-400 Hz
Compressors
- Control dynamic range by automatically reducing loud signals and bringing up quiet ones
- Threshold, ratio, attack, and release are the key parameters—threshold sets when compression kicks in
- Prevent distortion and maintain consistent levels—essential for dialogue-heavy shows where actors vary in projection
Effects Processors
- Add spatial and creative effects including reverb, delay, chorus, and modulation
- Hardware units are dedicated and reliable; software plugins offer flexibility and variety within a DAW
- Reverb creates acoustic space—a dry vocal can sound like it's in a cathedral or a closet depending on your settings
Compare: Equalizers vs. Compressors—EQ shapes which frequencies you hear, while compressors shape how loud those frequencies get over time. Both live on your console, but they solve different problems. FRQ tip: if asked about "tonal adjustment," think EQ; if asked about "level consistency," think compression.
Output Devices: Where Sound Meets the Audience
Output components convert processed electrical signals back into acoustic energy. Proper selection and placement determine whether your audience hears clarity or chaos.
Speakers (Main/House)
- Transducers that convert electrical signals into sound waves—the final step in the signal chain
- Passive speakers require external amplification; active speakers have built-in amps and often include DSP
- Coverage pattern and placement determine whether every seat hears balanced sound—work with your designer on sightlines and sound lines
Monitor Speakers
- Provide performers with a mix they can hear onstage—separate from what the audience hears
- Floor wedges point up at performers; in-ear monitors (IEMs) deliver personal mixes directly and reduce stage volume
- Monitor mixes are often different from front-of-house—actors may need more of themselves, musicians more of the click track
Headphones
- Enable private monitoring without affecting the room—essential for sound engineers during mixing
- Closed-back designs isolate external sound for focused listening; open-back designs provide natural spatial imaging
- Critical for calling cues when you need to hear the mix while remaining silent in the booth
Compare: Main Speakers vs. Monitor Speakers—both output sound, but mains serve the audience while monitors serve the performers. A common mistake is assuming they carry the same mix. During tech, confirm your sound team is checking both systems.
Signal Routing: Connecting the Chain
These components ensure signals travel cleanly and efficiently between all other equipment. A system is only as strong as its weakest connection.
Audio Cables
- Physical pathways for audio signals—quality and condition directly impact sound integrity
- XLR cables (balanced, 3-pin) are standard for microphones and professional gear; TRS (balanced, 1/4") for instruments and line-level; RCA (unbalanced) for consumer equipment
- Longer runs require balanced cables to reject interference—know your venue's cable inventory and have backups ready
Crossovers
- Divide the full audio spectrum into frequency bands routed to appropriate speaker drivers
- Low frequencies go to subwoofers, mids to woofers, and highs to tweeters—each driver handles only what it's designed to reproduce
- Active crossovers process the signal before amplification; passive crossovers work after—most modern systems use active
Amplifiers
- Boost line-level signals to speaker-level—providing the power speakers need to move air
- Power amplifiers drive speakers; preamplifiers boost weak mic signals before processing
- Impedance matching matters—mismatched amp and speaker impedance can damage equipment or degrade sound
Compare: Cables vs. Crossovers—cables move the entire signal from point A to point B, while crossovers split that signal by frequency. Both are invisible to the audience but critical to system function. When troubleshooting, check cables first (they fail more often).
Power and Protection: Keeping It All Running
These components ensure your system receives clean, consistent power and stays protected from electrical problems. Neglecting power management is the fastest way to ruin expensive gear.
Power Conditioners
- Filter and regulate electrical power to all connected audio equipment
- Protect against voltage spikes, surges, and brownouts—a single lightning strike can destroy an unprotected system
- Reduce electromagnetic interference (EMI) that causes hums and buzzes in your audio signal
Digital Production: Recording and Playback
Modern stage management increasingly involves digital audio tools for sound effects, music playback, and archival recording.
Digital Audio Workstation (DAW)
- Software platform for recording, editing, arranging, and mixing audio—industry standards include QLab (playback), Pro Tools, and Logic
- Non-destructive editing means you can experiment without losing original files—essential for iterating on sound designs
- Integrates with audio interfaces for input and often controls playback cues during performances
Compare: DAW vs. Mixing Console—a DAW handles recorded audio and playback cues, while the console manages live signals in real time. Many productions use both: the DAW fires sound effects, and the console blends them with live mics. Know which system controls what.
Quick Reference Table
|
| Signal Input | Microphones, DI Boxes, Audio Interfaces |
| Signal Processing | Mixing Console, Equalizers, Compressors, Effects Processors |
| Signal Output | Speakers (Main), Monitor Speakers, Headphones |
| Signal Routing | Audio Cables, Crossovers, Amplifiers |
| Power Management | Power Conditioners |
| Digital Production | DAW, Audio Interfaces |
| Dynamic Control | Compressors |
| Frequency Shaping | Equalizers, Crossovers |
Self-Check Questions
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Trace the signal path from an actor's voice to the audience's ears—what five categories of components does that signal pass through?
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Both equalizers and crossovers deal with frequency. How do their functions differ, and where in the signal chain does each typically appear?
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A guitarist plugs into a DI box, but the signal is noisy and weak. Name two possible causes and which component you'd check for each.
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Compare active speakers to passive speakers. In what venue situation might you recommend one over the other, and why?
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Your lead actor's mic is feeding back during a quiet scene. Using your knowledge of the signal chain, identify three points where adjustments could solve the problem and explain what you'd ask the sound engineer to try.