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9.) SYSTEM SETUP
For the best performance of your sound system, setup carefully the system`s gain structure. Gain structure is a term that refers to
the various levels at each point of your sound system. The result of a good gain structure and a correct setup is a maximum signal
headroom and a minimum of noise. In this operation manual we can show only a basic instruction how to setup a correct gain
structure and how to get up the system running as quick as possible. If you want to go deeper into this issue there are lot of books
to study.
Start setting up your system at the Mixer and work your way toward the amplifier. A system with the lowest noise floor and maxi
-
mum overall gain will have most of its gain at the mixer.
Setup the mixer so that all sound sources are adjusted to deliver a signal without clipping, close to the 0db level and a fader positi-
on close to 0dB.
Adjust the master level of the mixer to 0dB fader position for the target maximum output level.
If there are components like DSP´s between the mixer and amplifier setup them up to reach the 0dB level at the target max. output
level of the mixer.
For power amplifiers keep in mind that they are designed to produce a set amount of gain.
The function of the input level potenti-
ometer typically is to adjust the signal level coming into the amplifier’s input stage. Even with the input level potentiometer turned
down the amplifier can still reach full rated output power; it just takes more input drive level from your mixer to achieve it.
This issue is most misunderstood by many users.
To setup the right working level of the amplifier it is necessary to adjust the correct input sensitivity and correct level of the input
potentiometer.
Please also refer to the user manual of the mixer or sound source to find out the output level at 0db. This can help to find the right
setup.
Set the input sensitivity switches to 2,0 Volt and check if the amplifier can reach the maximum output level without clipping.
The mixer should supply a signal with 0dB output level which is the target maximum output level.
If the amplifier is clipping turn down the input level potentiometer.
If the maximum output level of the amplifier cannot be reached set the input sensitivity to 1,4V and try again.
Follow this procedure till the nominal operation level of the amplifier is found.
9.7) Setting System Gain Structure
Clip
Audio Source
(Mixer)
Noise Floor
Desired
Output Level
Headroom
DSP
(DSM-428)
Amplifier
To High
the DSP will clip
nominal operation
To low
Noise level to high
6dBu
6dBu
Amplifier
Amplifier
Lower the sensitivy
Increase the sensitivy
6dBu=1,54V
