High Level System Characteristics - Bosch PRAESENSA Installation Manual

PRAESENSA
3.2

High level system characteristics

Secure IP‑infrastructure
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Effective power utilization
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Highest system availability
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Bosch Security Systems B.V.
PRAESENSA is a networked sound system in which all system elements are connected to
OMNEO. Built upon multiple technologies, including IP and open public standards,
OMNEO supports AES67 and Audinate's Dante for audio communication and AES70 for
system control, with additional network security implemented using AES128 and TLS,
offering real‑time authentication and audio encryption on IP as protection against
malicious attacks.
OMNEO offers a mature, professional‑grade media networking solution that provides
interoperability, unique features for easier installation, better performance, and greater
scalability than any other IP offering on the market.
PRAESENSA multi‑channel power amplifiers have the unique capability of power
partitioning, the total power budget of the amplifier can be freely shared across the
output channels.
The class‑D amplifier channels operate at high power supply voltages for direct drive 70 V
or 100 V outputs without the need for output transformers that would limit the maximum
output power of a channel. This also improves efficiency and audio performance and
lowers the weight and size of the amplifier. Galvanic isolation of the amplifier outputs, as
required by EN 54‑16 and other emergency sound standards, is provided by isolated DC/
DC converters and the isolated Ethernet connections. The amplifier channels have a load
independent, flat frequency response that accept loudspeaker loads between zero and
full load. Each channel serves a separate zone or part of a zone.
The total amount of output power is defined by the redundant power supply and the
heatsink, and because both are shared between the amplifier channels, it doesn't matter
how many loudspeakers are connected to each channel, as long as the total combined
load does not exceed the maximum of 600 W for the whole amplifier and a load > 300 W
is not connected to any other channel than channel 1. A spare amplifier channel is also
included to take over a failing channel, a very cost- and space‑effective redundancy
measure because this spare channel uses the same redundant power supply and heatsink
too.
The flexibility of variable output power for each channel makes it possible to utilize most
of the available amplifier power. Traditional multi‑channel amplifiers have a fixed
maximum output power per channel. If a channel is not fully loaded, or even not used, the
remaining power capability of that channel cannot be claimed by one of the other
channels. PRAESENSA systems typically only need half the amount of amplifier power
compared to systems with traditional fixed maximum power amplifiers, saving on space,
energy and cost.
PRAESENSA offers the highest system availability due to conservative derating of all
components, supervision of all critical signal paths and functions, and built‑in redundancy
of all critical system elements.
PRAESENSA devices have high margins for safety and temperature stability. This is
illustrated by the fact that PRAESENSA devices are quite unique in that they may be
operated at altitudes of up to 5000 m (16404 ft), an important requirement in Peru, Chile,
India, China and other countries. At this altitude the air is less dense and the cooling
capacity of air is decreased, making heat removal less effective. Also, the dielectric
Installation manual
System introduction | en 15
2019.11 | V1.00 |