Quick start for installers: planning a one-room Auracast system

A single room with one transmitter, such as a church, a council chamber, a meeting room or a classroom, is the simplest Auracast job. It is also where shortcuts show. This checklist follows the Bluetooth SIG's transmitter guide, Auri's best practices and the field rules Bettear teaches for its CASTER, each labeled.

Before you go

• Seats and expected attendance. In the US, the loan receiver count comes from seating capacity (ADA Table 219.3).
• Who will listen: visitors' phones, hearing aids, loan receivers. Plan receivers either way.
• One program or more (a second language, a second room)? Check how many broadcasts your transmitter can carry before you quote.
• Photos of the room and the sound system, if the venue can send them.

On the survey

• Walls: note any brick or concrete wall between the transmitter and a group of listeners. Plan a second transmitter for that space rather than more power (Bettear's rule of thumb: a solid wall means a new zone).
• Mounting points: high, central, clear view over the seats. Note the ceiling height.
• Sound system: find a spare output that can carry a dedicated, post-fader mix. If the system is all digital, find out who can add an output.
• Network and power: PoE switch port and cable route if your transmitter needs them.
• Radio: note Wi-Fi access points and any 2.4 GHz wireless microphones. Auri's guide asks you to check the transmitter "is not impacted by Wi-Fi or other signals, and vice versa." See Auracast and Wi-Fi.

Placement

The SIG guide: install "as central as possible within the intended coverage area", in "the highest possible location", and avoid "enclosures such as cupboards, or behind metal partitions or counters."

More detail in transmitter placement and mounting height.

Audio feed

Our checklist for the feed, with the SIG's level and mono guidance:

• A dedicated output, labeled, protected from scene recalls.
• Post-fader, so it follows what the operator does.
• No loudspeaker processing (room EQ, delay, feedback suppression).
• Steady level: automatic gain control or gentle compression. The SIG reference level is a long-term average of -35 dBFS (about 70 dB SPL), peaks no higher than -3 dBFS.
• Mono for speech, especially where hearing-aid users listen: the SIG guide asks transmitters to send a separate mono stream rather than rely on receivers to mix stereo.
• A microphone straight into a transmitter needs a mic-level input (and phantom power for condenser mics). Some transmitters have line-level inputs only; check the datasheet and add a preamp or small automixer if needed.

Broadcast settings

• Name: something visitors recognize, such as "Grace Church Main Service". The SIG asks for names that let visitors "easily identify its contents".
• Quality: Standard Quality on. Public transmitters must always send it, and hearing aids depend on it.
• Open or private: open, unless neighbors must not listen.
• Power: start low (next section).

Prove it works

The SIG method: start at a lower power, "use an Auracast receiver to walk throughout the intended coverage", raise the power a step at a time until "reception is consistent throughout the intended coverage area", then "repeat the coverage check when the room is being used."

Our routine signs off three things separately:

1. Signal at the farthest seats, at ear height (the UK code of practice uses 1.2 m seated and 1.7 m standing), noting which receiver you used.
2. A quiet band at the busiest hour, checked with a Wi-Fi or spectrum analyzer. A signal-strength reading does not show interference.
3. Listening with the receivers people will use, including a hearing aid through its app if you can.

The commissioning guide covers the route, the record and what to call it.

What to leave behind

• A record: positions, settings, readings, receiver used, empty or occupied, date.
• Join cards and signs with the broadcast name and a QR code. In the US, signs include the International Symbol of Access for Hearing Loss (ADA §216.10).
• The loan receiver kit with neckloops for at least a quarter of the receivers (US), charging, and a sign-out routine.
• Brief training for whoever runs the loan desk.
• With the venue's approval, register the location with the Bluetooth SIG once the broadcast "is fully deployed and accessible."