Least possible’ approach, 1 ‘least possible’ approach – Sonnox Oxford Dynamics User Manual
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4.6 General Programme Compression
4 COMPRESSOR
4.6.1 ‘Least Possible’ Approach
The first and most obvious, which we will call the
‘least possible’ approach, is to leave
the majority of the programme uncompressed, forcing the compression to deal only with
the louder passages. This method has a definite psychological advantage in that one gets
the feeling that the majority of the programme remains unaffected. There is also some
possible technical merit (especially for legacy designs) in that the compressor is working
‘less often’ and over a restricted range, thereby avoiding some of the potential errors in
the application.
The above graph illustrates this kind of approach. The situation here is that the
programme goes ‘over’ on the loud passages, so we seek to control the loud portion only
by setting the threshold relatively high (-5 dBr) and setting the ratio high enough (ie.
between 3:1 and 4:1) to prevent the ‘over’. With the Oxford compressor, the threshold and
gain make-up controls can be used to accommodate this approach over a 24 dB range of
relative input levels, without change in the sonic character of the programme.
This method has the major disadvantage of risking increased rate of change disturbance
because the transition between non-compressed and compressed programme regions is
sharp. There is therefore a considerable reliance on longer time constant settings in order
to reduce the sonic effects of the compression. In other words, we need to seek to
control the rate of change using time slewing rather than level progression. Whilst this
approach would naturally form a good basis for using the compressor as an audio effect,
it is less suitable for composite programme control.