The sounding head with no optical chamber. Two channels report against it — 2 for heat, 5 for supervision — and that pairing is the signature of a heat sensor sounder on a panel display.
It earns its keep in kitchens, plant spaces and car parks that still need audible coverage: a smoke head there becomes a false-alarm source, while a standalone sounder would consume a second address and a second set of terminations.
Technical data
| Label marking | H/S |
| Sensing and output | Heat, tone sounder |
| Analogue channels | 2 and 5 |
| Sound output | 85 dBA at 1 m EN 54-3 average; +3 dB in turbo |
| Standards | EN 54-5:2000 A1:2002 and EN 54-3:2001 A1:2002 A2:2006 |
| Baffle ring | White (sounding) |
Specifications from 4188-1073 issue 3.
Compatibility
Mount on S4-701, or add S4-705 to a base already installed — the plate is a compliance item on an EN 54-3 device, not a trim. Its silent counterpart is S4-720.
Installation
Settle turbo mode at commissioning. The extra 3 dB is genuine, but volume and power demand in turbo run significantly above non-turbo, and the loop calculation must reflect whichever setting you leave behind.
Full details: S-Quad heat sensor sounder — installation data — 4188-1073 issue 3 · 28 pages · turbo and non-turbo tone mapping, H/S two-channel entry
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