Setting the Gain
Input gain is designed to take an audio signal, and adjust it to the level which the mixer understands.
All audio circuits, mixers included, produce a low level of electronic noise or hiss, and while this can be made very low by careful design, it can never be completely eliminated. It is also true that any audio circuit can be driven into distortion if the input is too high in level; hence care has to be taken when setting the input level so as to preserve the best possible sound quality. Ideally the input signal should be as high in level as possible while still leaving a margin of safety to prevent distortion on loud sections. This will ensure that the signal is large enough to render the background noise insignificant, whilst keeping the signal clean. The remaining safety margin is known as Headroom.
To set the gain on the mixer;
- Press the PFL/Solo switch on the relevant input.
- Adjust gain/input sensitivity until meters read within the yellow (‘3’ to ‘6’ on meter scale). This allows for the extra 10dB of gain that is available on Soundcraft input faders.
- Release PFL/Solo.
- Repeat for all other inputs.
NB: EQ affects gains settings. If you adjust the EQ you will need to re-check your gain level using the above method. Once you have optimised the gain your mixer will give the best possible signal quality with the minimum of noise and distortion.
Balancing Fader Levels
Faders allow you to make fine adjustments to your sounds and act as a visual indication of the overall mix levels.
It is important to keep your input faders around the ‘0’ mark for greater control. This is because fader scales are typically logarithmic and not linear, so if your fader position is near the bottom of its travel then even a small movement will lead to huge leaps in level. Similarly try not to have your fader at the top of its travel because this will leave you no room to further boost the signal.
See diagram below.
Balancing Output Levels
Master Outputs
Set your master outputs to ‘0’ on the scale. There are two reasons for this:
- You have the maximum fader travel for fading out your mix.
- If your faders are set below ‘0’ you will not be getting the full benefit from the meters because you will only be using the first few LEDs on the meter scale.
NB: Your mixer is not an amplifier. So the master output faders should be set to maximum (‘0’ on scale). If extra output is required, then turn up your amplifier.