Summary
Practical guidance for Auracast in theatres: range, placement, power, PIN codes, audio level, latency, loan receivers and communication.
Key findings
- Manufacturers often state theoretical ranges of up to 100 m, but real range is about 30 m. In a fully occupied room with heavy Wi-Fi, the distance for interference-free reception can be considerably shorter than in an empty room.
- Mount the transmitter high, above the audience, on walls or on the ceiling; ideally the farthest seat should be no more than 20 to 30 m away.
- Most professional and many low-cost transmitters run at 10 mW (10 dBm), which the article calls the maximum permissible in Europe. Theatres should use maximum power; reducing power to limit range is not recommended because it puts less sensitive receivers at risk when the venue is full.
- A PIN code (4 to 16 digits) is needed only where discretion is required and reception outside the venue is unwanted. If one is used it should be new for each event and clearly displayed, for example at the entrance; where possible a PIN should be avoided, to make handling simpler for technicians and the audience.
- Manufacturers, the SIG and standards committees do not yet agree on a reference level: the SIG recommends -35 dBFS; TV content is often -27 to -23 dBFS and music -16 to -14 dBFS. The article recommends about -25 dBFS for theatres, with a light compressor (about 2:1) and a limiter as a possibly better approach than automatic gain control.
- With a Dante or AES67 feed, the console's digital output level in dBFS equals the stream level, provided the transmitter adds no gain.
- About 40 ms is considered the maximum acceptable difference between room sound and the stream. This is hard to meet near the stage: transmitter-to-receiver delay is at best under 40 ms, but total delay through headphones and hearing aids is often about 70 ms. Picture-to-stream difference should ideally not exceed 45 ms.
- Switzerland's SIA 500 currently gives a guideline of 10 receivers or 5 to 10% of the audience; this is now considered too high and is likely to fall to 4 receivers in the coming revision. Loan receivers must be free.
Limits
Expert guidance based on Swiss practice; no measurement data or method is reported. EN 300 328 allows up to 20 dBm e.i.r.p.; 10 dBm is the level above which its adaptivity or airtime limits apply. Machine-translated from German.
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Cited in
- Should the Auracast stream be delayed to line up with the loudspeakers?Open
- How far does one transmitter really reach in a full room?Partly answered
- What audio level should the stream carry: -35 dBFS or louder?Disputed
- Auracast, hearing loop, infrared, RF or Wi-Fi: which suits which room?Disputed
- How many receivers and neckloops does each code require, and how should a loan pool be run?Partly answered
- How do many transmitters share one broadcast across a large venue?Open
- How much do crowds, phones and Wi-Fi reduce reliability?Open
- Can Auracast serve outdoor events?Not reliable yet
- Open or protected: when should a venue broadcast need a code?Open
- How much delay does Wi-Fi streaming add, and when does it matter?Not reliable yet
- What works in courtrooms, council chambers and other meeting rooms where speech must be heard by all and kept in the room?Partly answered
- What works in theatres and cinemas, and what do the rules ask of them?Partly answered
- What works in stadiums and arenas, and what do the rules ask of them?Partly answered
Cite this source
Graf B (Pro Audito Schweiz). Bluetooth Auracast in theaters and event venues. Proscenium no. 3, pp. 10-11, Swiss Association of Technical Stage and Event Industry; English reprint by the Center for Hearing Access. September 2026. https://centerforhearingaccess.org/wp-content/uploads/Proscenium-Technical-article-Bluetooth-Auracast-in-theaters-and-event-venues-1.pdf (accessed 9 October 2026).
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