Analysis of a feedback-controlled limiter using a logarithmic measuring scale

Feedback-controlled variable-gain limiting and compression systems are used to limit the maximum signal or dynamic range of a signal. By using a logarithmic weighting scale in analyzing such a device, we found that the attack time and overshoot of the gain reduction are directly dependent on the delay of the gain-control feedback loop. With the optimum loop gain, the attack time is approximately four times the loop delay. For a given rate of rise for the input signal in dB/s, the overload at the output is proportional to the reciprocal of the delay time. If the loop gain is set too high, the gain reduction overshoots the proper value and produces a "hole" in the program.