The short answer
Every phone camera connected to Broadcasteer has three microphone switches on its tile in the Studio:
- Noise suppression
- Echo cancellation
- Auto gain control
All three are off by default.
Leave them off for a room of voices: a cell group, a prayer circle, a Bible study, a panel. Turn them on for one person in a noisy place: someone speaking into the phone at a busy event, an interview outdoors.
That is most of what you need. The rest of this page explains why these switches matter so much, and how to place the phone so the whole group is heard.
Why a phone "hears" only one person
Phones are built for video calls. When a browser opens the microphone, it normally switches on the same processing a video call uses: remove background noise, cancel echo, keep the level steady.
For one person talking into a phone, that processing is excellent. For a group, it is a disaster. The voice closest to the phone is loud and clear, so it is treated as the speaker. Everyone else, a metre or two away, is quieter and further off, so it is treated as noise, and removed.
I learned this the direct way. The first long stream from a cell group came back with my voice perfectly clear and everyone else faint or missing. The phone had done exactly what a video call wants. It just was not a video call.
So the Studio now starts every phone with all three off, and gives you a switch for each, per camera.
What each switch does
Noise suppression tries to remove steady background sound: fans, air conditioning, traffic. It also removes quieter voices it decides are not the main speaker. Off for groups. On for one voice in a noisy space.
Echo cancellation tries to remove sound that comes out of a speaker and back into the microphone. It is essential in a video call where the phone is also playing the other people. In a room where the phone is only listening, it has nothing useful to do and can chop the ends off words. Usually off.
Auto gain control keeps the level steady by turning quiet sound up and loud sound down. For one speaker who moves around, it helps. For a group, it keeps chasing whoever is loudest and pumps everyone else up and down. Usually off.
Step by step
- Connect the phone as a camera the usual way, by scanning its QR code.
- Find its tile in the Studio. Once the phone is connected and has reported what its browser allows, the three switches appear beside the volume icon.
- Check they are all off for a group. Lit means on.
- Place the phone (see below).
- Do a short test. Have two or three people speak from where they will actually sit, at their normal volume. Listen on headphones in the booth, or record a minute and play it back.
- Adjust one switch at a time if something is wrong, and test again.
Changing a switch does not interrupt the video. The phone swaps its microphone input in place. The tile lights from what the phone says it actually applied, not from your click, so if the phone refuses a change the switch snaps back and you can see the truth.
Why a switch might be dashed out
Not every phone lets every setting be changed. iPhones in particular do not let the browser switch off noise suppression or auto gain control. Rather than hide those switches, the Studio draws them dashed and disabled, so you can see why a tap does nothing.
If you are relying on a phone to pick up a whole group, an Android phone gives you more control. An iPhone still works for one clear speaker or a small, close group.
Placing the phone for a group
The switches decide what the phone keeps. Placement decides what it hears in the first place.
Put it in the middle, not at the edge. A phone on a table in the centre of a circle hears everyone at roughly the same distance. A phone on a tripod behind one person hears that person and the backs of everyone else.
Lower is often better than higher. At table height, voices reach the microphone directly. Mounted high on a stand, the phone hears more of the ceiling and the room.
Keep it away from the noise. Not next to the fan, the air conditioner, the kitchen door or the window onto the road.
Mind where the microphone is. Most phones have a microphone on the bottom edge. Do not rest that edge against a cushion or tuck it into a case pocket.
Keep it plugged in. A long stream drains a phone quickly, and many phones start saving power in ways that affect the network connection when the battery gets low.
When a phone is not enough
A phone microphone set correctly is genuinely good for speech in a small room. It is not a replacement for a sound desk.
For music, take a feed from the mixer into the Studio's audio input instead. Singing, instruments and a room full of voices together are exactly where a phone struggles.
For one speaker who matters most, a lapel or handheld microphone into the phone or the Studio will beat the phone's own microphone every time. The existing guide Lav, shotgun, whatever they brought covers using those through a phone.
For a large room, one phone in the middle cannot hear the back rows well. Use the church's sound system and take its mix.
A quick checklist
- Group of voices: all three switches off.
- One person, noisy place: noise suppression on, the others as needed.
- Phone in the middle, at table height, away from fans and doors.
- Plugged in.
- Thirty seconds of test audio from where people will actually sit, before you go live.