Sirus Live M416, Руководство пользователя, Страница: 31 / 45

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(typically clipping at greater than +20dBu/7.74V). With a channel routed at unity gain from preamp
input to main output, the mixing console boasts a massive 116dB dynamic range. The signal can pass
through many stages which affect its level within the console, the channel, its EQ, fader, pan, a group
mix and its fader, on to the main LR mix with its master fader, through the matrix, and of course any
inserted equipment. The output XLR provides the professional st4dBu/1,23V nominal level to
the next stage in the audio chain, typically a speaker processor such as a limiter or crossover, or
straight to the amplifier. The amp boosts this signal to tens of volts to move the speaker cones so
producing the audible sound.
To get the best performance from your system, it is important that you set up the gain structure
correctly within the console and also within and between the connected equipment. Ideally, each
circuit should be set to clip at the same time if the signal become too hot, in other words each would
have similar headroom relative to its nominal operating level. The resulting dynamic range is the
difference between the highest noise floor and the lowest headroom through the system. The
performance is only as good as the weakest link.
The mixing console provides comprehensive metering to check every point within the console signal
path. Use the channel meters and PFL/AFL system to set the gains and mix levels to average around
‘0’ meter reading with usual peaks around ‘+6’. Reduce the gain if the red ‘+16’ or ‘PK’ indicator lights.
Use the equipment meters to set each item within the system path to operate at its nominal level. We
advise that the processor or amplifier trims are so set that the console outputs can drive up to their
nominal ‘0’ level. It is a common mistake to set amplifier trims to maximum sensitivity when this results
in the console master faders being operated at very low positions, with low meter readings, and
reduced dynamic range and therefore audible residual system hiss.
11.2. Using the Oscillator/Noise Generator
The mixing console includes a useful signal generator able to produce a pure 1 kHz sine wave tone, or
pink noise test source. This is invaluable in testing the system components and setting up the correct
gain structure. The generator can be routed independently to the various console outputs.
Use the 1 kHz to line up the connected equipment. For example, a recorder, video camera or
broadcast feed from the matrix. Route the tone to the groups and turn up GRP1 in the matrix. Set the
matrix GRP1 and LEVEL controls to their 3 o’clock ‘0’ positions. Press the matrix AFL and adjust the
oscillator level until the console monitor meters read ‘0’. Next adjust the recorder input trim so that its
meters also read ‘0’. The recorder is now correctly aligned to the operating level of the console.
Similarly, you could match the console LR output to a DSP speaker processor by sending the tone LR,
setting the faders for output meters reading ‘0‘, and then trimming the processor input for ‘0’ on its
meters. To prevent a loud tone through the speakers it is best to do this with amplifiers turned off.