MENU DESCRIPTION
bracket (see on the picture above, channel 2 is selected). Then turn the wheel to change
the headroom setting (from – 12 dB to 0 dB).
You can select multiple channels by pressing several “select” buttons at the same time.
When a selected channel reaches the maximum value, it will cease to increase by
continuing to turn the wheel, but other selected channels may still increase the setting: be
careful not to change a gap between two channel settings when selecting multiple channels
at the same time.
In some special circumstances (cardioids setups for example) it is mandatory to have same
headroom settings on two or more channels. Then, changing the headroom on one of
these channels will automatically adjust the headroom on the other channels.
Headroom concept
The headroom settings adjust the input/output analog gain to ensure the best matching
between program material and NXAMP internal gain structure.
With heavy content, like open air rock concert, you will need the full input range sensitivity.
This is the most typical situation. In that case, the headroom should be adjusted to 0 dB.
Analog input
level control
24 Bits
ADCs
Analog A
Analog B
Analog C
Analog D
Digital Signal
Processor
24 Bits
DACs
Analog Outputs
level control
Amp ch1 Input
Amp ch2 Input
Amp ch3 Input
Amp ch4 Input
Default headroom position (0 dB) situation :
Max input level
Max Output Level
Example above shows large input attenuation and large output gain. Overall gain is 0 dB (before amplifier).
But in quiet environment, like background music or small acoustic set, you won’t use the
full dynamic of the NXAMP input converter. In that case, you can lower the headroom
value, meaning that the input headroom of the amplifier is reduced; thus improving the
effective resolution used on the analog to digital input converter.
Analog input
level control
24 Bits
ADCs
Analog A
Analog B
Analog C
Analog D
Digital Signal
Processor
24 Bits
DACs
Analog Outputs
level control
Amp ch1 Input
Amp ch2 Input
Amp ch3 Input
Amp ch4 Input
Min headroom position (-12 dB) situation :
Max input level
Max Output Level
Example above shows small input attenuation and small output gain. Overall gain is 0 dB (before amplifier).
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