Chapter 10: Monitoring, Solo, Talkback & Utilities
A mixing console is only as effective as the engineer's ability to accurately monitor audio, communicate with the stage, verify signal continuity, and manage multiple open microphones. The Behringer X32 and Midas M32 include dedicated control room monitoring circuitry, dual talkback communication matrices, an onboard test signal oscillator, a 100-band Real-Time Analyzer (RTA), and a 8-channel Dan Dugan-style speech automixer.
This chapter details solo modes, talkback routing, system calibration with the oscillator, and speech automixing.
1. Control Room & Headphone Monitoring
Located on the upper right of the console surface is the dedicated MONITOR section. This hardware drives both the physical rear-panel Control Room outputs (for studio monitors or booth speakers) and the dual 1/4" headphone jacks located on the front underside cheeks of the mixer.
| Control | Function |
|---|---|
| Level knob | Independent analog volume for the monitor / headphone outputs |
| Mono | Collapses the monitor feed to mono |
| Dim | Lowers the monitor output by 20 dB |
| Talk A / Talk B | Activate talkback |
| Talk level knob | Preamp gain of the talkback microphone |
Solo Modes & Logic:
Press the MONITOR screen button to access the configuration tab:
| Setting | What you hear | Use it for |
|---|---|---|
| PFL (pre-fader listen) | The raw signal right after preamp and low cut; fader and mute have no effect | Checking input gain and hum |
| AFL (after-fader listen) | The signal after fader, pan and mute | Checking stereo in-ear mixes and subgroups |
| Exclusive solo | On: pressing a solo releases all others. Off: solos add up | Off for listening to a group of channels |
| Solo dims | The monitor level drops by 20 dB while a solo is active | Avoiding a sudden blast in your ears |
2. Talkback A & Talkback B Communication Matrix
The console features two completely independent talkback paths: Talkback A and Talkback B.
| Talkback source | Description |
|---|---|
| Internal mic | Built-in omnidirectional condenser capsule |
| External mic | Dedicated rear XLR talkback input (+48V available) |
Destinations are set separately for Talk A and Talk B; a typical setup:
| Destination | Typical use | Talk to it? |
|---|---|---|
| Mix buses 1–8 | Stage wedges | ✔ |
| Mix buses 9–16 | Musicians' in-ear monitors | ✔ |
| Matrices 1–6 | Green room / backstage | Optional |
| Main LR | House PA | ✘ Leave off during the show |
Push-to-Talk vs. Latch Mode:
- Momentary (Push-to-Talk): Hold the
TALK Abutton while speaking; releasing it immediately cuts communication. - Latch Mode: Tap
TALK Aonce to latch talkback ON; tap again to turn OFF. (Configure latch behavior under Monitor → Talkback).
Production Talkback Best Practice:
- Talkback A: Assigned exclusively to Buses 1–8 (Stage Wedges & Musician IEMs) to talk directly to the band during rehearsals.
- Talkback B: Assigned to Aux Out / Matrix 6 (Green Room, Stage Manager, or Lighting Booth) for crew intercom communication without distracting the band.
3. Test Signal Generator (Oscillator)
The onboard oscillator generates precision test tones for verifying cabling, system continuity, speaker phase, and acoustic room tuning.
Generator Types:
- Pink Noise: Equal energy per octave. The acoustic standard for room equalization, RTA measurement, and subwoofer crossover phase alignment.
- White Noise: Equal energy per Hertz. High-frequency heavy hiss used for testing HF transducer response.
- Sine Wave: Pure single-frequency test tone adjustable from 20 Hz to 20 kHz in fine 1 Hz increments.
System Verification Workflow:
- Navigate to Monitor → Oscillator.
- Select Sine Wave at 1000 Hz (or Pink Noise).
- Set level to -20 dBFS.
- Set Destination to Main L/R (or individual Mix Buses).
- Unmute the generator. Listen and verify that all speaker enclosures, amp racks, and line returns are functioning cleanly without hum, distortion, or intermittent drops before the performers arrive.
4. The 8-Channel Automixer (Dan Dugan Gain-Sharing)
Available on Channels 1 through 8, the onboard automixer employs a licensed implementation of the industry-standard Dan Dugan speech gain-sharing algorithm.
| Without the automixer | With Dugan gain sharing | |
|---|---|---|
| 4 open speech mics | Comb filtering (hollow sound), four times the room reverb and HVAC noise, high feedback risk | Total gain is held constant at unity (0 dB) |
| One person speaks | All four mics stay fully open | That mic gets full gain, the other three drop by about 15 dB |
| Two people talk | — | Gain is shared 50/50 |
| Sound | — | Changes happen within milliseconds — no gating artifacts, no clipped syllables |
Setting Up the Automixer:
- Patch your speech and dialogue microphones into Channels 1 through 8.
- Navigate to Channel → Config (or press the Automix tab in the Home menu).
- Enable Automixer for the desired channels.
- Assign channels to Group X or Group Y (allows running two independent panels simultaneously).
- Weight (Priority):
- Sets the relative sensitivity of each microphone (-12 dB to +12 dB).
- Set the Moderator / Keynote Pastor to +3 dB Weight, and panel guests to 0 dB. When the moderator speaks, the system automatically prioritizes their voice over interrupting participants.
5. 100-Band Real-Time Analyzer (RTA)
The console includes a high-resolution 100-band RTA integrated into every screen layer:
- Bar Display: High-contrast 100-bar frequency distribution with peak-hold needles.
- Spectrograph Mode: Continuous scrolling waterfall display highlighting persistent acoustic feedback frequencies over time.
- EQ Curve Overlay: Displays real-time audio spectrum directly behind your channel PEQ and 31-band graphic equalizers, allowing you to instantly visualize and notch out feedback squeals during live performances.