Zoom Participants Not Being Heard Over Loudspeaker when 100+ connections (other Zoom callers can hear the audio)

Hey ​@Michael Lazarus 

Thank you for sharing.

Possible Causes & Recommendations

1. Audio Congestion / Network Latency

Large meetings (100+ participants) can introduce significant data traffic.

• Latency and buffering may delay or drop audio routed to the room's system.
• Environments with high participant counts can cause packet queuing issues, affecting audio rendering on local endpoints.

Recommendations:

• Conduct a network test for bandwidth and latency. If possible, prioritize or isolate the meeting's audio stream.
• Keep in-room participants and the Zoom client on a high-quality, dedicated network connection.

2. Audio Routing & Loudspeaker Device Configuration

When output sound is not correctly configured, audio may fail to reach the physical loudspeakers:

• Common on Windows, especially using Realtek audio:
  • Audio enhancements may interfere with the output.
• Zoom app may have misconfigured audio output or be muted at the app level:
  • Users have reported cases where the Zoom app output was muted in the Windows volume mixer, even though system audio functions normally.

Recommendations:

• In Windows Settings → Sound, verify the correct output device is selected.
• Disable audio enhancements for the loudspeaker device.
• Open the Zoom app Settings → Audio:
  • Use Test Speaker to confirm sound output is working.
  • Check that Zoom’s own app-level output is not muted in Windows Volume Mixer.

3. Zoom Client Behavior with High Participant Counts

Some behaviors may only surface in sizeable meetings:

• In instances where many connections exist, Zoom may manage audio streams differently, potentially limiting or gating which audio channels are forwarded to certain endpoints.
• Though Zoom’s documentation doesn’t explicitly mention thresholds, anecdotal evidence suggests large meetings can impact shared media performance.

Recommendations:

• Test using Host or Co-Host controls—especially for muting/unmuting—to see if changing roles affects audio routing.
• Check whether using Zoom Rooms (dedicated AV hardware endpoints) or a wired broadcast output yields more consistent results.

4. Audio Device Interaction / Echo Suppression

Though not directly indicated in your description, issues may arise from device echo cancellation or multiple active audio endpoints:

• Having multiple active audio devices (e.g., PC speakers, soundboard, video conferencing mic) in the same physical space can cause conflicting audio routing and potentially block sound output.

Recommendations:

• Ensure only one active audio output is routed to the loudspeaker system during the meeting.
• Avoid unnecessary devices or mute individual elements when not in use.