When a voice alarm system fails to reach STI ≥ 0.50, excessive room reverberation (RT60) is usually to blame. Because the Bedrock SM50/SM90 includes a full 1/3-octave RT60 analyzer (T20, T30, EDT per ISO 3382), you can immediately diagnose the room acoustics on site.
Recommended reverberation times T_soll per DIN 18041:2016 for Group A rooms.
⚠️ Important Note on Open-Plan Offices (ISO 3382-3):
ISO 3382-3 strictly requires full STI (indirect impulse response method), Class 1 instrumentation, and an octave-calibrated omnidirectional dodecahedron speaker. Measurements in simplified STIPA mode, with Class 2 meters, or with directional speakers (such as a TalkBox) are not permitted for ISO 3382-3—use our Akulap ISO 3382-3 PC System (Art. 30001) or rental kit (Art. 20005) instead!