Audio Signal Flow DiagramEasyStagecraft Course · Tier 1B · Module 2 (Speak Sound) · v1.0 · "mic → speaker, decoded in 7 stages"

Why this matters. When the engineer says "we've got gain-staging issues on channel 4", you need a mental map of where in the signal chain that problem could be. This diagram is the road map: it traces audio from a microphone on stage, through every processing stage, out to the audience. After this sheet, you'll know which stage the engineer is talking about + what tools they have at each.

The signal chain · top-to-bottom

1. SOURCE Voice · instrument · pre-recorded 2. MICROPHONE Dynamic · condenser · wireless 3a. WIRELESS RX (if RF mic) 3. CABLE / DI XLR · 5-pin DMX equiv · DI for instruments 4. STAGE BOX Multi-input → multi-core to FOH 5. MIXING CONSOLE (the brain) Gain / Trim (input level) HPF / EQ (tone shape) Comp / Gate (dynamics) FX bus (reverb/delay) Fader / Aux send (level + routing) → routed to FOH master + monitor aux sends 6a. FOH AMPLIFIER + SPEAKER Active speaker (built-in amp) · Top + Sub 6b. MONITOR AMPLIFIER + SPEAKER Wedge or sidefill (back at performer) 7a. AUDIENCE (receives FOH mix) 7b. PERFORMER (receives monitor mix)

Stage-by-stage glossary

StageWhat happens hereWhat can go wrongWho fixes
1. Source Voice, instrument, or pre-recorded audio creates sound. Performer too far from mic, instrument unplugged, playback laptop unmuted. Sound op or performer notices; talks to engineer.
2. Microphone Sound waves are converted into an electrical signal. Wrong mic for the job (covered in microphone decision tree), capsule damaged, phantom power off on a condenser. Engineer.
3. Cable / DI The signal travels from the mic to the stage box. DI boxes convert instrument-level signals (high impedance) to mic-level signals (low impedance, balanced). Faulty cable, bad solder joint, DI box dead, connector loose. Engineer or stage hand. ~2-5 min fix.
3a. Wireless receiver (if RF mic) Wireless body-pack transmits to a receiver, which converts back to balanced audio. RF dropout, low battery, antenna misaligned, frequency conflict. Engineer.
4. Stage box Multiple mic signals collected into one box on stage; converted to digital + sent via single multicore cable to FOH. Loose connector, faulty preamp on one channel, multicore cable damage. Engineer. Often hot-swappable.
5. Console Five-stage processing per channel:
• Gain — set input level
• HPF/EQ — shape tone
• Comp/Gate — control dynamics
• FX bus — add reverb/delay
• Fader/aux — set output level + route to FOH + monitor mixes 		Gain-staging issues (too quiet or distorted), wrong EQ for the source, comp set too aggressively, feedback (EQ-fixable), routing not patched correctly. Engineer. Most issues here are fixable mid-show without anyone noticing.
6a. FOH amplifier + speaker Console output drives the FOH amplifier (often built into the speaker), which produces the audience-facing sound. Speaker failure (rare), amp clipping, time-align issue between top + sub. Engineer.
6b. Monitor amplifier + speaker Separate aux-send mix is sent to a monitor wedge or sidefill for the performer. Wrong mix on wedge (vocal too quiet, band too loud), feedback into wedge. Engineer. Adjust during soundcheck or song breaks.
7a. Audience Sound waves reach audience ears. Room acoustics (reverb-y, slap-back), volume too loud or too quiet for the space. Engineer tunes during bump-in.
7b. Performer Performer hears their own voice + the band, balanced for their monitoring needs. Performer can't hear themselves over the band; engineer adjusts the wedge mix. Engineer + performer feedback.

When something goes wrong — which stage?

Use this map to follow what the engineer is saying:

You don't need to fix any of these. You just need to follow the engineer's diagnosis — and not panic when they take 5 minutes to find it.