SoundCraft Spirit SX, Руководство по смешиванию

Страница: 11 / 40

B. Setting Up a Basic Mix
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:
1 You have the maximum fader travel for fading out your
mix.
2 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.
SECTION 3: Mixing T
e
chniques
11
0
-20
+6
-30
-40
-50
-60
10
5
0
5
10
15
20
30
∞
LOW
LEVEL
SETTING
FADER
OFF
TYPICAL
SETTING SOLO
Linear level
adjustment from
-20 to +10dB
TYPICAL GAIN SETTINGS FOR DIFFERENT INPUTS
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.
FIG. 3.7
FIG. 3.8
13924 Inners 7/8/01 2:56 pm Page 11