The difference between feedback and feedforward compressors is that feedback compressors analyze an already “compressed” output signal to further apply slightly more gain reduction.
In layman terms a feedback compressor will initially compress the input signal and then check the output to see if the signal is above or below the threshold of the compressor.
If the signal happens to be above the threshold then more gain reduction will also be applied by the feedback compressor resulting in a gradual increase of gain reduction.
Feedforward compressors analyze the input signal fed in the compressor and will therefore apply appropriate gain reduction depending on how low the threshold is set.
So in other words, feedforward compressors are more accurate compared to feedback compressors in terms of the overall signal processing.
The main reason behind this level of accuracy is that a feedforward compressor “knows” which signal is on its way and will apply a precise amount of gain reduction.
However feedback compressors due to being less precise can sound more musical but this depends heavily on the program material which is being fed into the compressor.
The following is a non-exhaustive list of feedback compressors:
- Waves CLA-76
- T-Racks Black 76
- Urei 1176
- Neve 2254
- Waves V-Comp
- Neve 33609
- Fab-Filter Pro-C ( set in *CLASSIC* mode)