Bosch PRM-4P600 - Set the Output Mode (AMP MODE)

Power amplifier Installation | en 17
Bosch Security Systems B.V.
Installation manual
2023-01 | V02 | F.01U.402.247
5.1.1 Set the output mode (AMP MODE)
APD
AMP MODE
CH 1
CH 2
CH 1
CH 2
OFF
ON
100 V
4 Ω
8 Ω
70 V
LP
FLAT
HP 1
HP 2
DUAL PARALLEL CH 1/2
SPEAKER EQ
CH3
CH4
CH3
CH4
100 V
4 Ω
8 Ω
70 V
LP
FLAT
HP 1
HP 2
IN1 to ALL
OFF
ON
DUAL PARALLEL CH 3/4
AMP MODE
SPEAKER EQ
100 Volt and 70 Volt modes
The use of either the 70V or 100V modes allow connection of high impedance (HZ)
loudspeaker lines without using output transformers. In this case the maximum number of
loudspeakers connected to an output channel is only limited by the amplifier channel output
power.
It is recommended that this mode should be used if the distance between amplifier and
speaker is larger than 50m of cable distance (approx. 150ft) and/or a high number of small
speakers with transformers are used.
When 100V or 70V is selected a 50Hz High Pass filter is automatically activated to reduce the
possibility of loudspeaker transformer saturation to ensure the best performance.
8Ω mode
In 8Ω mode the power amplifier reaches rated output power having a load of 8Ω connected.
4Ω mode
In 4Ω mode the power amplifier reaches the rated output power with a single cabinet rated at
4Ω or two cabinets of 8Ω each, or up to 4 cabinets of 16 ohms each. These configurations
can be driven by each amplifier channel. This mode usually used if multiple speakers with
medium or low‑power rating are driven in low impedance mode (LZ).
Refer to
– Indicators, controls and settings, page 16