Creating a Room (Host)

The host creates and owns the session. To get started:

• Select your microphone input and speaker output from the Audio Devices section
• Click Test Mic to confirm your microphone is working — speak and watch the level bar
• Click Test Output to confirm your speakers or headphones are active
• Optionally enable your camera using the Enable checkbox
• Your room code is displayed — click Copy Join Link to share it
• Click Create Room & Host to enter the session

Joining a Room (Participant)

• Open the link shared by the host — the room code will be pre-filled automatically
• Configure your audio devices and test them
• Enter your name or role (e.g. CAM-1, TX-OP, SOUND)
• Click Join Room

PTT — Push to Talk

Hold the HOLD TO TALK button on a channel to transmit your microphone audio to that person. Release to stop. This is the default mode for all channels.

Open Mic

Click the OPEN mode button on a channel to keep your microphone continuously active to that person — no need to hold a button. The PTT button will show ● OPEN MIC. Click PTT to return to push-to-talk.

Listen

Click the LISTEN button on any channel to monitor that person's incoming audio continuously, regardless of whether they are actively talking to you. Useful for monitoring a specific operator at all times.

Groups allow the host to create named collections of participants and talk to them all with a single PTT. To create a group:

• Click + NEW in the Groups panel (host only)
• Name the group and assign a colour
• Select the members from the connected participants list
• Click Save Group

Groups appear for all participants immediately. Any user can press a group PTT button to talk to all members of that group simultaneously.

Hot Mic is a host-only feature that makes a participant's microphone always active — transmitting to everyone in the session continuously, without them needing to press PTT.

• Go to the PARTICIPANTS section in the config sidebar
• Click the HOT button next to a participant's name
• Their channel card will show a red ● HOT indicator for everyone
• Other users click LISTEN on that channel to hear them
• Click HOT again to deactivate

Each TX channel has an independent audio processing chain. Click DSP on a channel to open the processor panel:

• Noise Gate — attenuates the signal when it falls below a threshold. Useful for removing background noise between speech. Set threshold, attack, and release times.
• Compressor — reduces dynamic range for more consistent levels. Set threshold, ratio, attack, release, and makeup gain. A live gain reduction meter shows how much compression is being applied.
• 3-Band EQ — high pass filter, low shelf, mid peak (parametric), and high shelf. Shape the tone of each operator's voice independently.

Each processor has an on/off toggle and takes effect in real time with no interruption to the connection.

Click 1K TONE on any channel to send a 1kHz sine wave at −8 dBFS to that specific user. This replaces your microphone signal on that connection only and is useful for checking audio routing and signal levels. The TX meter will show the tone level. Click again to stop and restore your microphone.

Enable your camera on the setup screen to share video with all participants. Remote video feeds appear automatically in the Video Feeds panel. Each feed tile includes:

• LISTEN — click to monitor the program audio from that video source independently from the comms audio
• Volume slider — adjust the level of that feed's program audio
• Level meter — shows the audio signal from that feed in real time
• ⛶ Expand — hover over a feed and click to go fullscreen

Program audio uses its own independent audio context and can be routed to a different output device from the comms audio. This is useful for monitoring a Blackmagic Web Presenter or similar device's embedded audio.

• A modern browser — Chrome or Edge recommended. Firefox supported. Safari has limited WebRTC capabilities.
• HTTPS is required for microphone and camera access. Serve the file from a secure host (Netlify, GitHub Pages, etc.) or use localhost.
• All participants must have a stable internet connection. The system uses TURN relay servers so strict corporate firewalls are supported.
• A Firebase Realtime Database is required for signalling. The database rules must allow read/write access to the rooms path.

Broadcast Web Comms is a single-file browser application built on WebRTC. It uses a full-mesh peer-to-peer topology — every participant connects directly to every other participant. There is no central media server; audio and video are routed peer-to-peer via encrypted DTLS/SRTP streams.

Firebase Realtime Database is used exclusively for signalling (session coordination). No media passes through Firebase. Once a session is established, Firebase traffic is minimal and the system remains fully functional even if Firebase connectivity degrades temporarily — existing peer connections are unaffected.