Master Audio
Joker Series (JK46A). Version 1.0
Sep14
19
To avoid loudspeaker damage because of input overload issues, Joker systems build
in an
input monitoring system that prevents the cabinet from being
continuously operated at excessive input signal levels
. After a long period of
exposure to high input levels (more than 5 minutes over +15dBu / 4.5V), the cabinet
will enter in
Input Overload Protection
mode, meaning that:
- The output signal will be
reduced by
20dB
- All limiter LEDs will be lit
- The front power led will blink
- A message will be shown in the LCD
(
Input Overload
)
To get back to the normal operation mode, the input level should be reduced to
+5dBu (1.4V). After the level reduction, the system needs around 10 seconds to
recover the normal operation mode.
d) Adaptive Loudness Compensation (ALC).
ALC
is a DSP algorithm developed by the Research and Development team at
Master Audio
to improve the listening experience when the cabinet is being used at
low reproduction levels.
Under this listening condition, the behaviour of human ear is to naturally enhance the
level of middle frequencies. The lower the level, the higher is the middle frequency
enhancement. To compensate for that effect,
ALC
applies a correction to the
frequency response of the system.
In order to do that,
ALC
automatically senses the
average signal level at the input: when this level is
low, the DSP will apply loudness compensation
curves (based on Fletcher-Munson’s equal
loudness contours), that will dynamically adapt the
frequency response of the cabinet to the listening
conditions.
This feature will only influence the frequency response when the input signal average
is below 6dB of the nominal input, that is, when the cabinet is performing at levels
below half of its rated program power. In the range between -6dB and 0dB in respect
to the nominal input, the
ALC
will not modify the response.
ALC
is active by Factory Default, and may be enabled or disabled by the user. To do
that, go to the Configuration Menu, and select the option ALC (Loudness).
When
ALC
is active (Auto), it will be displayed in
the main screen.
ALC (Loudness)
Disabled
Auto .
Back
FLAT
30
0.0dB
Lock
ALC
