Bosch HORN LOUDSPEAKER 15W LONG THROW SIP - LHN-UC15L-SIP

Bosch LHN-UC15L-SIP 15W SIP Horn Loudspeaker, Long Throw, IP66

The Bosch LHN-UC15L-SIP is a 15W class D SIP-enabled horn loudspeaker built for demanding outdoor and industrial public address deployments where network-based voice evacuation, paging, and two-way communication must survive extreme environments. Delivering up to 122 dB SPL at 1 meter (PoE+ mode) with a long-throw horn profile covering 380 Hz to 11 kHz, this unit is designed for large perimeters, transport hubs, loading docks, campuses, and critical infrastructure sites where audio must carry clearly across distance and ambient noise. A single RJ45 connection handles both power (PoE or PoE+) and SIP signaling — no separate power wiring required.

Overview

The LHN-UC15L-SIP integrates a 15 W class D amplifier, a SIP stack with G.711, G.722, and Opus codec support, 300 MB of onboard message storage, and an integrated electret condenser microphone into a weather-hardened ASA horn enclosure. It registers directly to a SIP PBX, IP intercom controller, or access control system as a SIP endpoint — making it a first-class network audio device rather than a passive speaker driven by an external amplifier. The stainless steel (grade 316) mounting bracket, IP66 ingress protection, and -40°C to +55°C operating range make it equally viable in coastal, industrial, and arctic-climate installations.

Browse the full Bosch surveillance and communications line for complementary access control and intercom products, or explore the IP intercom and access control category for SIP-compatible door stations and controllers to pair with this loudspeaker.

Key Features

• 122 dB Max SPL (PoE+, 1 m, 500 Hz–8 kHz): At full 15 W output over PoE+, the horn produces 122 dB at one meter — enough acoustic headroom to cut through construction noise, forklift traffic, or high-ambient industrial floors. In PoE-only mode (7 W rated), SPL tops at 119 dB, still suitable for most exterior and warehouse deployments. Choose PoE+ when you need the last few dB of margin.
• 15 W Class D Amplifier: Class D topology keeps idle power draw under 6 W (PoE+) and rated draw under 26 W — so you're not burning your switch's PoE budget when the speaker is between pages. Standard 802.3af (PoE, Class 3) handles 13 W rated; 802.3at (PoE+, Class 4) unlocks the full 26 W ceiling.
• SIP Endpoint with G.711 / G.722 / Opus: The unit registers to any standards-compliant SIP server. G.722 wideband support (50 Hz–7 kHz) produces noticeably more intelligible voice paging than narrowband G.711 alone — relevant when the announcement content is safety-critical. Opus is available for adaptive-bitrate scenarios over congested or variable-quality WAN links.
• 300 MB Onboard Message Storage (WAV, MP3, Ogg Vorbis, Opus): Pre-loaded evacuation tones, scheduled announcements, and multi-language messages play locally without relying on a real-time SIP connection. Network interruptions during an emergency don't silence the speaker — stored messages continue to play from internal flash regardless of uplink status.
• Effective Frequency Range 380 Hz–11 kHz (-10 dB): Long-throw horn profile with frequency-dependent beam narrowing — 100°×130° at 1 kHz (broad, fills a wide apron) tightening to 30°×30° at 4 kHz (focused high-frequency energy reaches distance). Aim precisely for long outdoor runs; accept wider coverage at close range without repositioning the unit.
• IP66 Ingress Protection, ASA Horn Body: IP66 blocks powerful water jets and total dust ingress — verified for outdoor mounting without any additional housing. ASA (Acrylonitrile Styrene Acrylate) resists UV degradation and impact better than standard ABS, maintaining appearance and structural integrity over years of rooftop or perimeter exposure.
• -40°C to +55°C Operating Range: Covers the full temperature envelope of northern Canadian winters and hot industrial environments in the same SKU. The storage temperature ceiling of +70°C means units can be warehoused in unconditioned trailers without risking damage before installation.
• Supervised GPI + GPO (3-pin screw terminals): The supervised general-purpose input (threshold-based: Short <0.75 V, On 0.75–1.25 V, Off 1.25–2 V, Open >2 V, max 48 V) allows direct wiring to a fire panel, door contact, or motion detector to trigger local playback. The GPO (switched to GND, max 48 V / 500 mA) can drive a relay, beacon, or strobe in parallel with the audio announcement.
• Stainless Steel Grade 316 Bracket: Grade 316 (molybdenum-alloyed) bracket resists chloride corrosion from coastal salt air and chemical washdown environments — a meaningful material choice over grade 304 when the install site is within a few miles of saltwater or inside food processing facilities.
• Integrated Electret Condenser Microphone: Enables two-way SIP calls from the field location — security staff can initiate intercom with a control room or gate station without a separate intercom device. The microphone is built in; no external mic wiring required.
• Analog Audio I/O — Line Level (3-pin screw terminals): One unbalanced line-in (max 1 V, impedance >10 kΩ) and one unbalanced line-out (max 1 V, impedance <100 Ω) on AWG 28–14 screw terminals provide a conventional audio path for integrating legacy PA systems, background music sources, or analog zone controllers alongside the SIP stack.
• ONVIF Discovery + HTTP/HTTPS Management: ONVIF Discovery support means compatible VMS and access control platforms can locate the device automatically on the network. HTTPS management and the Bosch LHN-UC15L-SIP's dual Ethernet speed (100BASE-TX / 1000BASE-T) fit cleanly into standard IT-managed security VLANs.

Integration & Compatibility

The LHN-UC15L-SIP connects to any SIP-compliant server or IP PBX, including Bosch PRAESIDEO, Bosch Praesensa, and third-party platforms supporting RFC 3261. The ONVIF Discovery profile allows VMS platforms and IP access control head-ends to enumerate the device. For PoE switch pairing, any 802.3af switch covers the 7 W rated draw; to unlock the 15 W (PoE+) rated mode and access 122 dB SPL, use an 802.3at-capable port — check your PoE switch power budget before deployment. The GPIO terminals interface directly with supervised fire alarm inputs and relay outputs on most conventional and addressable panels. The M20 polyamide cable gland accepts cable diameters from 5 mm to 12 mm, covering standard CAT6 and most multiconductor shielded cable jackets. For installations requiring multiple SIP audio zones, review a network audio planning guide for zone segmentation and SIP trunk capacity considerations.

Frequently Asked Questions

Q: What is the maximum SPL output of the LHN-UC15L-SIP, and does it require PoE+ to reach it?

A: Maximum SPL is 122 dB at 1 meter (500 Hz–8 kHz) when powered via PoE+ (802.3at, Class 4, up to 26 W). On standard PoE (802.3af, Class 3, up to 13 W), maximum SPL is 119 dB. The 3 dB difference is significant in high-ambient environments — use PoE+ if your site noise floor is above approximately 85 dB.

Q: What SIP audio codecs are supported?

A: The LHN-UC15L-SIP supports G.711 (both µ-law and a-law), G.722 wideband, and Opus. G.722 is the recommended codec for maximum voice intelligibility in paging applications; Opus provides adaptive bitrate for variable-quality network paths.

Q: Can stored messages play without a live SIP connection?

A: Yes. The unit includes 300 MB of onboard storage supporting WAV, MP3, Ogg Vorbis, and Opus files. Stored messages and tones can be triggered locally via the supervised GPIO input or scheduled playback, independent of SIP network connectivity.

Q: Is the LHN-UC15L-SIP suitable for coastal or corrosive environments?

A: Yes. The mounting bracket is stainless steel grade 316 (molybdenum-alloyed), which is specifically chosen for chloride-corrosion resistance in coastal and chemical-washdown environments. The ASA horn body resists UV degradation. IP66 rating prevents water jet and dust ingress.

Q: What is the operating temperature range?

A: -40°C to +55°C (-40°F to 131°F) operating. Storage temperature extends to -40°C to +70°C (-40°F to 158°F). The unit handles both extreme cold-climate and hot industrial deployments without a separate heater or thermostat enclosure.

Q: Does the LHN-UC15L-SIP include a microphone for two-way communication?

A: Yes. An integrated electret condenser microphone enables two-way SIP calls from the loudspeaker location. No external microphone or separate intercom panel is required for basic two-way audio.

James Everett

The LHN-UC15L-SIP (often searched as LHN UC15L SIP) is one of the more fully specified SIP horn loudspeakers I've deployed in perimeter and campus PA applications. What stands out in practice is the 3 dB SPL swing between PoE and PoE+ modes — 119 dB vs. 122 dB — which sounds modest on paper but translates to a meaningful coverage radius extension in high-ambient industrial environments. If your switch plant is already 802.3at-capable, there's no reason not to run it at full rated power from day one.

Technical Highlights:

• Frequency-Dependent Beam Control: The 100°×130° horizontal-vertical spread at 1 kHz narrows to 30°×30° at 4 kHz. In long-throw aiming you get broad low-frequency fill near the speaker and focused high-frequency energy down-range — useful for intelligible speech paging at 50–100 m without a separate delay speaker cluster.
• Supervised GPI with Threshold Levels: The input distinguishes four states (Short, On, Off, Open) and tolerates up to 48 V — wires directly to most fire alarm NAC outputs or dry-contact relay outputs without an interposing relay or voltage divider. The GPO (48 V / 500 mA switched to GND) drives a standard 24 V strobe or beacon in the same conduit run.
• 300 MB Onboard Storage with Local Trigger: Stored WAV/MP3/Opus messages triggered by the GPIO input provide a hardened fallback when IP connectivity is disrupted. For sites with unreliable WAN or where IP network failure during an emergency is a design consideration, this onboard buffer is the spec that justifies the unit over a simpler SIP audio adapter.

Deployment Considerations:

• The M20 cable gland accepts 5–12 mm cable diameter — standard CAT6 (typically 6–7 mm) fits cleanly, but if you're running armored or gel-filled outdoor CAT6 (which can exceed 9 mm), verify the jacket OD before ordering the gland size. A wrong gland choice on a rooftop install is an avoidable re-climb.
• PoE idle draw is under 5 W (802.3af) or under 6 W (802.3at). On a densely loaded 24-port 802.3at switch, account for the rated draw ceiling (26 W PoE+) in your power budget per port — not the idle draw — since multiple simultaneous evacuation announcements will push every horn to rated power simultaneously.

This unit is the right call for transport authority platforms, petrochemical perimeter fencing, and university campus PA backbones where a standards-based SIP endpoint, hardened mechanics, and local message resilience all need to coexist in a single outdoor-rated device.