Audio over IP (AoIP) Distributed Audio Systems

What’s the best way to design and power a complex audio system for a large, or multi-zoned, space? A 70V constant voltage distributed audio system can work well for background music and public address in large buildings. However, with this type of system there are typically limitations in terms of playback and functionality.

Many spaces these days, such as schools and hospitals, require full-duplex, two-way communication for voice calls, high quality audio, and other feature sets, including motion detection and alarm/alert system integration. These 70V systems were never designed to handle that complexity. Enter Audio over IP, or AoIP distributed audio systems.

With the advent of power over ethernet (PoE), a standard where inexpensive Category 5 cable (Cat 5) is used to send digital signals as well as up to 71 watts of power over long distances, a local amplifier can be installed directly onto speakers without the need to connect an outlet. Since a PoE system is low voltage, you can install it without hiring a licensed electrician.

What An AoIP System Can Do

A server, also known as a purpose-built computer or PoE switch, is used as a matrix, connecting audio sources and the amplifiers. Servers can also be connected to emergency broadcast websites, as well as outside sources that have a two-way communication link setup. Many AoIP speakers, which is a critical component in systems like Wahsega’s Carina Building Control Platform, have a built-in microphone, meaning a teacher can call the office from their classroom, or a hospital patient can call a nurse’s station with a simple push button setup.

AoIP distributed audio systems

Cat 5 cabling, which is abundant and inexpensive, in schools and hospitals is run from the server to a speaker’s amplifier, and from that amplifier onto the next amplifier. This sounds like it could introduce system failures if one speaker/amplifier fails, but because these are parallel connections at ethernet jacks, a PoE system has the same robust integrity as a 70V system. 

category 5 cable

Since AoIP is largely software-based, you can configure the speakers in several ways. This means you can tailor the frequency response, in addition to the SPL, for each speaker in each room and for each source. For voice calls, you can maximize a speaker’s intelligibility; for alerts, you can tune the speaker’s SPL and frequency response to maximize effectiveness. 

Creating zones, or groups of zones, can be as easy as drag and drop through the software’s graphic user interface (GUI) in some systems, and you can make changes in real-time; in a 70V system, this is mostly fixed at installation. Last but not least, these systems are typically future-proof and can be updated on-site or remotely with software updates.

AoIP distributed audio systems

Creating Your AoIP System

Remember AoIP is a good solution for getting power and functionality to your speakers, but the resulting sound will only be as good as the speakers themselves. If you want help aligning the technology and hardware, MISCO is happy to listen to your goals and work with you on a system that meets your needs and fits your budget. 

All images courtesy of the guide to custom speaker design, testing, manufacturing

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