LA Audio MPX10 - Manual (Page 30)

Page 30
C O M P R E S S O R
The Threshold control sets a DC reference level above which compression
can start. This is compared to the RMS voltage and when this exceeds the
reference the difference is forwarded to the Ratio control.
RATIO
The difference voltage from the Threshold stage is amplified or attenuated
depending on the setting of Ratio. This control voltage defines the amount
of compression once Threshold has been exceeded.