FLX-E Operations Manual Rev F
Page 13
Table of Contents
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7.1.2
System Drop-down Menu
There are four options on the System drop-down menu. The Set
System Configuration on Selected Device, Load Test on Selected
device, Update Firmware on Selected Devices, and Identify
Selected Device.
7.1.2.1
Set System Configuration on Selected Device
This option allows the user to set the device name,
and the overtemp warning and shutdown thresholds.
The current MCU and amplifier temperatures are
shown for reference. The user can also set the
method by which the device obtains an IP address
(DHCP –automatically) or set a fixed IP address.
7.1.2.2
Load Test on Selected Device
The FLX-E application provides a convenient method of testing the amplifier output loads. It does not
continuously monitor load impedance; nor does it measure impedance during the test process. It is
intended to detect significant changes in loads that would indicate a failed speaker or failed speaker
connection. It works by muting the input audio program and injecting an 18kHz test tone, and comparing
the current load on each channel to a set of reference values the user can establish at any time. This
process takes about 3 seconds.
To use this function, connect all low impedance loads, or
tap all high impedance speakers to the desired values.
Since there is some temperature dependence, allow the
amplifier to temperature stabilize for best results. Press
the “Take Reference Values” button on the Load Test tab.
You will hear several clicks as the channels are cycled
through. You will also hear an 18kHz tone. During this
process, the application records the amplifier current
draw for each channel. Once these values are set, pressing the “Load Test” button will rerun the same
sequence and report on the variance relative to the reference values. The repeatability is better than 1%.
Taking temperature variation into account, the repeatability is better than 3%.
Note that certain level controls for high impedance speakers (such as those manufactured by Atlas and
Lowell) adjust volume by changing the load impedance. In this case, changing the volume will result in a
variance reported by the application.
New reference values can be established at any time, and are recommended whenever a change to the
load on any channel is changed. However, once a new set of reference values is established, the previous
values cannot be restored. For that reason a message pops up when “Take Reference Values” is selected to
verify that this is your intent.
