I hate to be “that guy” that brings this dead horse back to life only to beat it further, but I would like to see real sidechain compression in Renoise.
Yes, I know about the signal follower and hydra, and I realize that they are powerful effects.
Yes, I know that you can use one of these in conjunction with a gainer effect to get the “my pad is pumping with my kick” effect.
No, this is not sidechain compression. Here’s why:
Take a look at the compressor in Renoise. See that “threshold” control? That selects the amplitude at which attenuation begins. See that “ratio” control? That controls how much attenuation happens after the signal passes the threshold. At a ratio of 2:1, if the signal passes the threshold by 3dB, the compressor attenuates the signal by 1.5db. See those “attack” and “release” controls? They affect how quickly the attenuation happens once the amplitude passes the threshold, and how quickly the attenuation stops once the amplitude falls below the threshold. Some compressors have a “knee” setting that softens the “slope” change of the attenuation to make it less obvious. Wikipedia has a good article on compression that explains these controls in more detail. Although any given compressor may only have a subset of these controls, all of these parameters have an effect on the way the compressor processes a signal, in more or less subtle ways.
For those unfamiliar with the term, sidechain compression refers to using a different signal as the “control” signal for the compressor than the signal that is actually being processed. This has the effect of the processed sound being reduced in volume as the “control” signal increases in volume, but only according to the settings on the compressor. That is, the processed signal is only reduced in volume as the control signal passes the threshold, and the amount it is attenuated is related as a ratio to the amount by which the control signal exceeds the threshold.
Now take a look at the signal follower and hydra effects. Do you see any of the controls that are on a compressor? How about on the gainer effect? Only the attack and release, right?
This means that the with the current workaround, as soon as the control signal has any volume at all, the gain of the processed signal is attenuated. There’s no threshold, which means no knee. Also, while you have the option of changing the scaling of the input value (logarithmic, linear, exponential etc.) and the min/max attenuation values, this doesn’t easily translate to a ratio of (dB over threshold) to (dB of attenuation).
Thus, sidechain compression is not possible with native plugins only, despite what some have said on this forum, and I feel it is sorely missed.
The main reason why I bring this up is because I really like almost everything about Renoise, and am considering making it my main music making software (despite what I’ve said here, I love the signal follower and hydra effects, and wish there were similar devices in other programs). However, the lack of sidechain compression alone is a dealbreaker for me, and means that I have to export all my tracks and mix in another program that has native sidechain compression (any given compressor that is bundled with a DAW today has a sidechain input). This is a tedious step that I would like to skip if possible.
No, I don’t want to buy a VST compressor. If there’s a free VST/AU compressor out there that doesn’t suck and has sidechain input, please let me know, but I’d still like to have it native because I don’t like the whole “external editor” mode of dealing with VSTs.
Whew, sorry for writing a book.
TL;DR: Signal follower doesn’t have compressor controls (most importantly threshold IMHO), so sidechain compression isn’t possible. I would like to see it added.