Public address (PA) systems: A complete guide + 7 areas of use

By better understanding PA systems, you can greatly enhance security, safety, and operational efficiency.   

In this blog, we explain what goes into spreading your message effectively.   

What is a PA system?  

A public address system allows you to efficiently speak directly to people by increasing the apparent volume (loudness) of a human voice. 

These announcements can be made live or prerecorded, scheduled or automated. To make sure your announcements gets where it’s needed and when it’s most needed a public address system can be divided into zones, one or many. 

A PA system consists of microphones and paging consoles, amplifiers, and speakers that lets you address large areas and many people all at once.  

How PA systems work  

A public address system often works in three stages.  

• Input
• Amplification
• Output  

The first stage is input. Sound is captured using a microphone or other input devices. The sound waves are converted into electrical signals.   

The second is amplification. The signals from the input stage are sent to an amplifier or active speaker, which increases the power of these signals so they can drive the speakers.   

Finally, it is the output stage. The amplified signals are sent to speakers, which convert the electrical signals back into sound waves, broadcasting the sound to your intended audience.  

What is the difference between analog and digital audio? 

Digital, or network-based, public address systems consist of 100% IP endpoints that connect directly to standard network infrastructure. This makes them easy to install, configure, and manage, without the need for dedicated speaker cabling. 

Because they are network-based, a digital PA system is also scalable and future-proof. You can adjust the size of the system over time and add, or update features as needs change. Each IP speaker contains all the necessary hardware built in, meaning you do not need a technical equipment room with centralized electronics in a rack. 

Most traditional analog public address systems used today are actually hybrid systems. They combine analog speakers with digital control components and are often better described as digitally controlled analog distribution systems. 

In a hybrid system, the main difference compared to a network-based PA system is the use of 70/100 V analog speakers. These speakers are connected to a central rack that contains the system’s digital components and intelligence. 

While the central rack can connect to a standard network, the speakers themselves require additional speaker cabling.  

Network audio adds significant value by making audio a fully integrated and flexible part of an organization’s IT infrastructure. Installation and management are simpler, as only a single network cable is typically required, and each speaker can be monitored and controlled centrally over the network. 

Operation and maintenance can also be handled by an organization’s own IT department, rather than relying on external support, which is often required for hybrid or analog systems. 

Compared to hybrid and analog setups, this results in fewer components, easier maintenance, and more cost-effective operation over time, enabled by greater flexibility and scalability. 

How much does a PA system cost? 

Before diving into the components of a PA system it’s important to discuss costs. While the cost of each system will vary depending on set-up, complexity, size, and layout of the site, it is important to consider the overall long-term total cost of ownership (TCO) of your system.  

Put simply, the TCO is the costs involved after the initial purchase and installation, such as maintenance, power consumption, and upgrades, and even training, services, and support. Given the lifetime of a system could be as long as 20 years, those costs can add up. 

For instance, the TCO for a digital public address system is often lower, due to it connecting to standard IT infrastructure using standard network cabling, its ease of scalability, and the freedom to expand without major reconfiguration. 

Avoid surprising costs after the system is installed and consider how an initial low-cost PA system may add up over time. 

5 components of a PA system  

1. Microphones and paging consoles  

A paging console is a specialized device used in public address systems for making announcements to specific areas (zones). 

You can also use standalone microphones to make simple call outs. 

A paging console serves as the central hub for initiating and directing audio communications within a PA system, and are more commonly used in:  

• Hospitals
• Schools
• Office buildings
• Warehouses
• Shopping centers  

Components such as network paging consoles complement your network speakers to create a complete public address system that enables live paging, prerecorded callouts, and two-way communication.  

You can easily set up different zones with the paging consoles, this enables efficient messaging to the right place. 

2. Amplifiers  

Amplifiers are crucial components of a PA system. Responsible for increasing the power of audio signals, they can drive speakers effectively. Amplifiers can either be standalone components placed in a standardized frame system or built into an active speaker. 

They ensure that the sound is loud and clear enough to reach the intended audience.  

3. Speakers  

Speakers are among the most critical components of a PA system.   

They convert the amplified electrical signals back into sound waves that can be heard by the audience and are vital in delivering clear and powerful audio. 

There are two forms of speakers, network and analog; analog speakers are typically less expensive and more suited for straightforward setups.  

Network speakers, however, offer greater flexibility, scalability, and advanced functionality, albeit at an initial higher cost.  

It’s worth remembering as previously mentioned above; an initial higher cost may save money over the full lifecycle of the system, when all TCO factors are taken into account. 

Here are some examples of network speakers used in a public address system:  

• Horn speakers
• Strobe speakers
• Cabinet speakers
• Explosion-protected speakers
• Ceiling speakers
• Pendant speakers
• Display speakers  

4. Cables and connectors   

Cables and connectors are essential components of an analog and hybrid PA system.    

They play a crucial role in maintaining signal integrity, minimizing interference and transmitting audio signals between various devices, ensuring reliable and high-quality sound reproduction. 

In analog and hybrid systems, multiple cables and connectors must be managed. In contrast, a network-based public address system typically uses a single standard network cable and connector. 

Managing the many cables and connectors in an analog or hybrid system requires technical expertise. The single cable used in a network-based system, however, follows standard networking practices, making installation and handling easier. 

5. Audio management software   

Audio management software are specialized software applications that play an instrumental role in PA systems. They are essential for functionalities like:  

• Zone targeted communication
• Scheduled announcements
• Prioritization of audio sources
• Remote health monitoring 

7 common areas of use of a network PA system 

1. Schools 

School PA systems are crucial for effective communication for facilitating daily announcements, emergency alerts, and targeted messaging to specific zones.   

Whether it’s announcements to classrooms, hallways, cafeterias, or outdoor areas, they ensure important information reaches students, teachers, and staff.  In some systems it can also be used for two-way audio, so an administrator can start a conversation with a classroom. 

In case of critical incidents, such as lockdowns, or severe weather, networked public address systems play a significant role and enable school admin enable school administrators to quickly and clearly communicate instructions to ensure the safety of everyone on campus.   

Many school PA systems include zone control features, allowing announcements to be targeted to specific classrooms, departments, or outdoor spaces.   

Additionally, these systems can be integrated with other technologies, such as bells, clocks, intercom systems, and video surveillance, to provide a comprehensive communication solution that streamlines school operations and improves efficiency.   

With ease-of-use top of mind, school PA systems are user-friendly, allowing school staff to operate them with minimal training.  

2. Warehouses 

Warehouses are a hive of activity, with a constant flow of goods being received, stored, picked, packed, and shipped. Therefore, it’s important that communication can be clear and immediate. 

Whether it is  

• Operational updates, such as shift changes, breaks, or the arrival of shipments
• Operational safety, through live or automated alerts and safety equipment reminders
• Protecting stock through intrusion deterrence   

An integrated and complemented network warehouse PA system can ensure the smooth and efficient running of a warehouse. 

3. Industrial sites/critical infrastructure 

The work carried out at industrial and critical infrastructure sites is essential. Everything from energy, water, and oil and gas facilities falls under this category. Therefore, it is important that operations can run as safely and securely as possible.  

Integrated or as complement with other systems such as fire alarms, mass notification, security systems, and process control systems provides a unified and coordinated response to various events.  

4. Outdoor and cities  

Outdoor PA systems are designed to provide clear and powerful audio coverage in open-air environments, making them perfect for public transport, crowd management, and critical messaging.  

Featuring robust and weather-resistant components, outdoor public address systems are designed to withstand various weather conditions. 

They often include multiple zones for targeted announcements to specific areas to offer safety, security, and efficiency. This makes them ideal for handling the requirements of wide-open spaces or traffic heavy cities.   

These systems can also be combined with other technologies like mass notification systems to offer a complete audio solution.   

In outdoor installations, public address systems often need to cover large areas, which in analog or hybrid systems requires extensive and costly cabling, sometimes involving roadworks or ground excavation. 

Network-based PA systems instead connect to existing network infrastructure, significantly reducing installation complexity and cost. 

They also allow central monitoring of speakers, which is essential for large, city-wide systems used for critical communication, ensuring no area becomes silent without being detected. 

5. Hospitals 

A public address system for hospitals is an essential tool in providing and enhancing safety for patients, staff and visitors. A few key applications include: 

• Code announcements to alert staff and initiate appropriate protocols
• Patient care announcements such as calling healthcare providers to certain rooms or areas or notifying staff about patient arrivals or transfers
• Operational updates such as shift changes, staff meetings, or maintenance schedules
• Multilingual support to communicate effectively with a diverse patient and staff population
• Visitor information such as visiting hours, hospital policies, or appointment calls. 

As previously mentioned, network PA systems can combine and complement emergency and security alerts, providing a safer and more secure environment for caregivers and patients. 

6. Retail stores/shopping malls 

A happy customer is a repeat customer, and so providing the best customer experience is essential. This may not be so easy during peak shopping hours or busy periods of the year. 

Here are just a few of the ways a shopping mall/retail store PA system can not only help staff, but can also enhance the customer experience: 

• Customer guidance in directing them to specific areas of the store or providing information about store layout and services.
• Promotional announcements can highlight special offers, new product arrivals, or upcoming events, thereby driving sales and customer engagement.
• Queue management to alert staff to queue build ups and customer wait times
• Background music can be played to provide a more pleasant and engaging environment
• Staff coordination, such as calling for assistance at checkout counters or announcing shift changes. 

PA systems for retail stores can also be used to complement existing fire, security, emergency alert systems, and be used for zone targeting, ensuring your message can be heard wherever it’s needed. 

7. Office buildings 

In today's fast-paced office environments, effective communication is key to maintaining productivity and ensuring smooth operations. An office PA system plays a crucial role in enhancing communication and coordination within an office setting through: 

• Background music in the cafeteria
• Provide emergency communication
• Visitor management can guide visitors with voice messages 

By allowing a PA system for office buildings to help streamline tasks, you can create a more effective and efficient environment. 

Axis PA System in action  

The Sacramento Regional Transit District (SacRT), USA, needed to address safety and cleanliness on its light rail system after experiencing a dramatic decline in ridership. Vandalism, unsightly trash, and anti-social behavior were driving customers away.  

To improve situational awareness and ridership experience, SacRT deployed at least two Axis Network Horn Speakers at every light rail station as part of its Cisco voice-over-IP public address system.   

Because the horn speakers are IP addressable, security can broadcast announcements to multiple speakers on the platform or direct a targeted message to a single speaker.   

“ This gives us the flexibility to inform everyone on the platform of schedule delays or other updates,” says Sandy Bobek, SacRT AVP of Technology, Innovations and Performance Monitoring.

 Or, for instance, if security staff monitoring the cameras sees someone in a green jacket smoking, they can direct a verbal warning to a specific network speaker that’s closest to that person and tell them to put out their cigarette. 

Since the new system was put in place, SacRT has been experiencing a steady increase in ridership. The combination of extra cameras, horn speakers, and incident management software is helping authorities quickly locate and stop undesired behavior.   

Summary 

Throughout this blog we have explored that PA systems are incredibly versatile, can be deployed in a wide range of environments, and can be used to handle any number of scenarios.   

Whether it is general announcements in a school or shopping center, targeted communications at a bus station, or complimenting emergency notification systems, PA systems are adaptable to meet your needs.   

Their scalability ensures that they can be tailored to specific settings. From small offices to large venues. The seamless integration capabilities of modern PA systems with other technologies allow for enhanced functionality and efficiency.