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Each PoE supply device (IP switch or power injector) has a certain maximum
output power capacity. This can limit the number of PoE outputs that can be set
on. For 4420A loudspeaker, calculate the output power for each output as 15.4
W for PoE and 30 W for PoE+. Ensure that the total power does not exceed the
switch or power injector total power.
Example: IP switch total power is 150 W. You use PoE+ and four outputs are
connected. The total output power is 4 x 30 W = 120 W. This is smaller than the
capacity of the Ip switch, 150 W. This scenario is acceptable.
PoE cable loss calculation
There is power loss in the Ethernet cable. The reason for the power loss is that
the CAT cable conductor is thin and has considerable resistance. The power loss
increases with increasing cable length. The maximum cable length is 100 meters
(333 feet). Calculate the power loss in cable at 25 mW/m or 7,4 mW/ft. 4420A will
automatically adapt to the power loss in the cable, but lower input power will
affect slightly the duration of the maximum SPL output. In order to minimize the
cable loss and to maximize the duration at maximum SPL, consider using power
injectors close to the loudspeakers or short cable runs.
ISS AUTOSTART
The automatic power function ISS (Intelligent Signal Sensing) powers the
loudspeaker automatically down when it is not in used and up when the use
resumes. ISS can be activated and adjusted with the Smart IP Manager
software. Powering down to standby happens after a set time when playback has
ended. Playback automatically resumes with an input signal exceeding the level
configured using the Smart IP Manager. There is a slight delay in the automatic
powering up. If this is undesirable, ISS can be disabled with Smart IP Manager.
The indented use of this loudspeaker requires that the IP network interface is
continuously enabled also in the standby mode. This enables the ISS to wake up
with an API command or in response to IP audio stream. The power consumption
in the ISS state for 4420A is 4 W. To save more power, the PoE+ power supply
in the Ethernet switch or PoE injector can be turned off. However, loudspeaker
wakeup will then take slightly longer time and the loudspeaker does not respond
to any command on the IP network while it is not powered.
SELECTION OF IP SWITCH
Smart IP and 4420A are fully compatible with standard Ethernet and IP switch
technology. Genelec recommends using gigabit speed managed IP switches with
full PoE+ on each of the outputs intended for 4420A loudspeakers. Managed IP
switches offer the ability to configure, manage and monitor the local area
Summary of Contents for 4420A
Page 1: ...4420A Operating Manual ...
