The Bedrock BIMK is an impulsive sound source kit including a balloon pistol and calibrated balloons for reverberation time (RT60) measurement and building acoustics assessments using the impulse response method. Impulsive source measurements are used for RT60 determination per ISO 3382, for situations where a continuous omnidirectional source is less practical, and as a supplementary method to the interrupted noise method. The kit is compatible with Class 1 sound level meters and acoustic analyzers supporting impulse response analysis.
The impulse response method for reverberation time measurement involves generating a brief, high-energy impulsive sound (balloon burst) and then measuring the resulting decay in the room. From the measured impulse response, EDT, T20, T30, and other reverberation time parameters can be calculated. This method is widely used in building acoustics for ISO 3382 compliant measurements and in situations where the room must be excited quickly from a point source with minimal setup time.
Both methods are accepted by ISO 3382. The BRELUXE05 omnidirectional source provides the most standardised and reproducible excitation and is generally preferred for formal ISO 16283 building acoustics documentation. The BIMK provides a faster and more portable alternative for preliminary assessments and for measurements in spaces where setting up powered loudspeakers is impractical. For highest accuracy and standards compliance in building handover documentation, use the BRELUXE05.
A typical BIMK measurement sequence: (1) Place the Bedrock i10 or i9 at the measurement position with microphone at the correct height per ISO 3382. (2) Position the balloon pistol in the source position — at least 1 m from any reflecting surface and at least 1 m from the measurement microphone. (3) Arm the instrument's impulse trigger and inflate the balloon to the correct calibration mark. (4) Puncture the balloon and allow the instrument to capture the impulse response. (5) Repeat at least three times per source-receiver combination; use at least two source positions and several measurement positions per ISO 3382 requirements. The instrument calculates EDT, T20, and T30 automatically from the measured impulse responses. Record all source-receiver combinations and average results as required by the applicable standard.
RT60 Measurement Guide · Building Acoustics Applications · Request a Quote · BRELUXE05 Omnidirectional Source