Bosch PRAESENSA, Installation Manual

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82 en | Amplifier, 600W 8-channel | PRA-AD608 PRAESENSA
2019.11 | V1.00 | Installation manual Bosch Security Systems B.V.
9 Amplifier, 600W 8-channel | PRA-AD608
9.1 Introduction
This is a flexible and compact multi‑channel power amplifier for 100 V or 70 V loudspeaker
systems in Public Address and Voice Alarm applications. It fits in centralized system
topologies, but also supports decentralized system topologies because of its OMNEO
IP‑network connection, combined with DC‑power from a multifunction power supply.
The output power of each amplifier channel adapts to the connected loudspeaker load, only
limited by the total power budget of the whole amplifier. This flexibility, and the integration of
a spare amplifier channel, makes it possible to utilize the available power effectively and use
less amplifiers for the same loudspeaker load, compared to using traditional amplifiers.
Digital sound processing and control, adjusted to the acoustics and requirements of each
zone, allow for better sound quality and speech intelligibility.
9.2 Functions
Efficient 8‑channel power amplifier
– Transformerless, galvanically isolated, 70/100 V outputs, with a total loudspeaker output
power of 600 W.
– Cost and space saving, integrated, independent spare channel for fail‑safe redundancy.
– High‑efficiency in all operating conditions; dissipation and heat loss is minimized to save
on energy and battery capacity for backup power.
– Flexible partitioning of the available output power across all amplifier channels to use it
effectively, significantly reducing the amount of required amplifier power in a system.
Flexibility in loudspeaker topologies
– A/B outputs on every amplifier channel to support redundant loudspeaker wiring
topologies. Both outputs are individually supervised and disabled in case of a fault.
– Class A loop wiring possible between the A and B loudspeaker outputs.
– Load independent frequency response; the amplifier channels can be used with any
loudspeaker load up to the maximum, without any change in audio quality.
Sound quality
– Audio‑over‑IP, using OMNEO, the Bosch high‑quality digital audio interface, compatible
with Dante and AES67; audio sample rate is 48
kHz with 24‑bit sample size.
– Large signal to noise ratio, wide audio bandwidth and very low distortion and crosstalk.
– Digital signal processing on all amplifier channels, including equalization, limiting and
delay, to optimize and tailor the sound in each loudspeaker zone.
Supervision
– Supervision of amplifier operation and all of its connections; faults are reported to the
system controller and logged.
– Loudspeaker line integrity supervision without interruption of audio, using end‑of‑line
devices (separately available) for best reliability.
– Network link supervision.