IP speakers: between intercom and notification – demystifying the technological boundary

IP speaker technology is nothing new, but it continues to raise many questions in the security and emergency communications communities. More and more devices combine a loudspeaker, microphone, and network interface, often integrated into surveillance or intercom systems. But can these devices complement—or even replace—traditional loudspeakers used for alarms, mass notifications, or evacuation announcements?

VoIP is not AoIP

First, we must distinguish between two worlds that are often confused:

• Voice over IP (VoIP) : based on protocols such as SIP or RTP, designed for two-way communication and telephony;
• Audio over IP (AoIP) : based on protocols such as Dante or AES67, designed for real-time multichannel audio transport with precision synchronization.

VoIP-type IP speakers are generally duplex, with a built-in microphone. This makes them excellent tools for intercommunication or audio surveillance, but it also raises privacy concerns. These devices behave more like telephone terminals than notification points, which complicates their use in notification or public alarm systems.

Clear normative boundaries

To date, there are no recognized standards—neither ULC-S541 (loudspeakers for fire alarm systems), nor ULC-S576 (mass notification system), or even ULC-S524 (design and installation of a fire alarm system) – does not explicitly address loudspeakers connected directly to an IP network. IP protocols may in some cases be used. upstream (between servers, controllers, or amplifiers), but never at the notification endpoint. This is a major difference: in certified systems, the last link must remain electrically monitorable (impedance, open circuit, short circuit), which current IP solutions do not always offer natively.

In an analog system, the amplifier is physically connected to the speakers by a continuous electrical circuit. This connection makes it possible to detect a break, short circuit, or impedance variation, as the system directly «sees» the load of the audio network. Conversely, an IP loudspeaker is electrically isolated from the controller—data is transmitted via a digital signal over Ethernet or fiber optics, with no continuity of ground or measurable loop. It therefore becomes impossible to electrically monitor the status of the loudspeaker: monitoring is limited to logical signals (such as a network ping or SIP message).

A regulatory vacuum in Canada

Unlike the United States, where the Chapter 24 of NFPA 72 oversees emergency communication systems (ECS/MNS), the Canada does not yet have an equivalent standard.. Thus, an owner or an authority having jurisdiction (AHJ) may, at their discretion, accept an IP system for mass notification, subject to certain conditions, for example, that it is proven to be reliable, supervised, and redundant. This flexibility enables innovation, but it also transfers a significant amount of responsibility to the designer and integrator.

Technical advantages of IP speakers

1. Simplified infrastructure – A single cable for power and communication (PoE), without a central amplifier.
2. Native integration – Direct connection to security, video surveillance, or access control systems.
3. Embedded intelligence – Local functions such as audio detection, stored messages, or event triggering.
4. Flexibility of configuration – Individual addressing, granular volume control, call priorities, and dynamic routing.
5. Remote maintenance – Protocol-based monitoring (e.g., SNMP), event logging, and centralized software updates.

Disadvantages and limitations to consider

1. Variable audio performance – VoIP codecs (often G.711 or G.729) are limited to a bandwidth of 300 Hz to 3.4 kHz, far from 400 Hz – 4 kHz required by fire alarm standards (UL 1480, ULC-S541).
2. Network dependency – Requires a network 1 Gb/s stable, low latency, and prioritization of audio traffic (QoS).
3. Absence of physical supervision – Failures in speakers, local power supplies, or PoE ports may go unnoticed without an integrated monitoring system.
4. Software complexity – Each device is a microcomputer, subject to updates, bugs, or network vulnerabilities.
5. Regulatory non-compliance – None of these devices are currently certified for use in alarms or critical notifications.
6. Privacy – The presence of built-in microphones requires clear governance on the cybersecurity and privacy.

Best practices for safe use

For applications where IP speakers are deemed acceptable (e.g., mass notification not connected to the fire alarm), certain measures can improve system reliability:

• Separate networks (audio VLAN, management VLAN);
• Employ independent power sources (PoE-A/B or local DC);
• Implement a A/B topology installation;
• Validate the bandwidth and frequency response minimum (ideally compliant with ULC-S541);
• Document the supervision and recovery strategy in the event of a network failure or node loss.

Conclusion: technical maturity before regulatory compliance

IP speakers perfectly illustrate the line between innovation and standardization. They offer considerable potential for integrated communication and the smart buildings, but their adoption in critical environments must be done with caution and method. In the absence of a clear regulatory framework, the reliability, the redundancy, and the traceability become the essential pillars of any responsible design!