Bedrock BTB115 Advanced Talkbox — High-Power STIPA Generator for Large Venues & Outdoor PA Systems

The Bedrock BTB115 Advanced Talkbox is a high-power IEC 60268-16 STIPA signal generator delivering up to 115 dB SPL maximum output. It is designed for speech intelligibility testing in large auditoria, sports stadiums, outdoor PA systems, airports, railway stations, transport hubs, offshore PAGA systems, and any other challenging acoustic environment where standard-output talkboxes cannot achieve sufficient signal-to-noise ratio for valid STIPA measurement.

Achieving a valid STIPA measurement requires that the test signal level at the measurement position exceeds the background noise level by a sufficient margin. In large venues, reverberant spaces, or environments with high background noise, standard-output talkboxes often cannot provide enough signal at distant measurement positions. The BTB115 solves this problem with its 115 dB SPL output capability, ensuring valid STIPA measurements can be achieved at any measurement position in even the most challenging acoustic environments.

Key Features

• 115 dB SPL maximum output — for the most demanding acoustic environments
• IEC 60268-16 compliant STIPA test signal at all output levels
• Suitable for large auditoria, stadiums, outdoor PA, airports, railway stations, and offshore PAGA
• Adjustable output level for adapting to different venue sizes and background noise levels
• Robust construction for demanding field environments
• Compatible with all Bedrock Elite STIPA receivers: i10, i9, i5, SM50

Typical Applications Requiring High-Power Output

• Stadiums and arenas — large reverberant spaces with high ambient noise and long source-to-receiver distances
• Airports and transport hubs — high background noise levels from HVAC, crowds, and mechanical systems; large measurement areas
• Outdoor PA systems — loss of signal due to distance and wind; no acoustic reinforcement from room boundaries
• Offshore PAGA systems — very high background noise from machinery, compressors, and weather; regulatory requirements for PAGA commissioning
• Industrial facilities with heavy machinery — very high background noise making standard-output talkboxes insufficient
• Large ecclesiastical and heritage buildings — very long reverberation times requiring high signal levels

BTB115 vs BTB65

The BTB65 is suitable for most standard indoor environments. Use the BTB115 whenever the BTB65 cannot achieve adequate signal-to-noise ratio at all required measurement positions. When in doubt, the BTB115's higher output capability ensures measurement validity even if lower output would have been technically sufficient.

Practical Considerations for Large-Venue STIPA Commissioning

In large venues and outdoor systems, the number of required measurement positions for a complete STIPA commissioning survey can be substantial — major transport hubs and stadiums may require dozens of measurement positions, each covering a specific zone of the PA system. Efficient workflow is important: plan measurement routes to minimise walking time between positions, use the BTB115's adjustable level to optimise signal-to-noise ratio for each zone, and confirm that the test signal is correctly routed to the loudspeakers serving each zone before starting measurements. For voice alarm systems with multiple speaker zones, each zone must be tested independently with the BTB115 routing its signal through the relevant zone's speaker circuit. Document all measurement results, the PA system configuration at the time of test, and the BTB115 output level used for each zone — this information is required for a complete commissioning record under EN 54-16 and BS 5839-8.

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