Grandstream GSC3518HS SIP Horn Speaker

The Grandstream GSC3518HS is the outdoor horn speaker of the range: 50 W, up to 126 dBA, in an IP66 weatherproof body. It is what you mount on a yard wall, a loading bay or a factory floor when an ordinary ceiling speaker would simply be drowned out.

It also talks back. Three built-in microphones give 8 metres of pickup with AI-powered background noise reduction and full-duplex operation — so someone standing near the horn in a noisy yard can answer, and be understood, without walking anywhere. A horn speaker that only shouts is a different and much less useful product.

Power is unusually flexible: it accepts PoE, PoE+ and PoE++, and can pass PoE or PoE+ out to another device — useful where a camera or a second speaker shares the same long cable run to an outbuilding.

Key features

• 50 W output, up to 126 dBA — audible over machinery and traffic
• IP66 weatherproof — dust-tight, protected against powerful water jets
• Full-duplex talk-back — the yard can answer
• Three built-in microphones, 8 m pickup
• AI-powered background noise reduction — speech, not the forklift
• PoE, PoE+ and PoE++ input
• PoE / PoE+ output — pass power to another device on the same run
• SIP and multicast paging

Works with

• GSC3516 — the 15 W indoor talk-back speaker
• GSC3575 — a control station to page from
• GDS3725 — door entry on the same system
• Grandstream GWN PoE switches — check the power budget for PoE++
• Grandstream UCM IP PBX range
• All intercoms and paging

Frequently asked questions

How loud is 126 dBA in practice?

Loud enough to be heard across a yard over machinery — and loud enough that it should be aimed thoughtfully. Point it at the area that needs to hear it, not at the neighbours or at a spot where someone will stand right underneath it.

Can people really answer it?

Yes — three microphones with 8 metres of pickup and AI noise reduction, full duplex. That is the difference between this and a plain tannoy horn: you can hold a conversation with someone at the loading bay rather than shouting instructions into the air.

What does IP66 mean here?

Dust-tight and protected against powerful water jets from any direction — rated for permanent outdoor mounting through British weather. It is not rated for immersion.

What PoE do I need?

It accepts PoE, PoE+ and PoE++. A 50 W speaker at full output is not a small load, so check the switch's total power budget before hanging several off one switch — that is the usual thing that catches people out.

What is the PoE output for?

It can pass PoE or PoE+ on to another device, which saves a second cable run to an outbuilding — a camera at the same mounting point, for instance.

GSC3518HS or GSC3516?

Where it goes. Indoors and out of the weather, the 15 W GSC3516 is enough and costs far less. Outdoors, or on a loud production floor, only the horn will do.

Covering a noisy or outdoor area? Call 0333 242 1314 or email sales@clisecure.com — describe the space and the noise and we will work out placement and power with you.