SP 91 Calibrators

The SP 91 Acoustic Pulse Source is a hand-operated impulse device built for RT60 reverberation time measurements in small to medium-sized rooms and echoey spaces up to approximately 200 m² (600 m³). Its purely mechanical, wood-based construction requires no batteries or external power, making it a reliable and eco-friendly alternative to balloon-based impulse sources. The device produces a broadband acoustic pulse exceeding 125 dB(C) peak sound level at 1 metre in semi-free field conditions, ensuring sufficient signal-to-noise ratio across the audible frequency range. It is well-suited for building acoustics assessments, room acoustic surveys, and educational demonstrations. Each unit ships with hearing protection and a lightweight carrying bag for easy field deployment.

Key Specifications

• Peak SPL >125 dB(C) at 1 m
• Broadband spectrum
• Room coverage up to 200 m² / 600 m³
• Mechanical operation (no batteries)
• Weight ~2.27 kg
• Dimensions 300×150×100 mm

Applications

• Building acoustics
• Reverberation time (RT60) measurement
• Room acoustic surveys
• Educational demonstrations