it's fairly common for an effect or processor to increase or decrease amplitude as part of its function. the problem is, this can color our perception of the result, as it's widely known that louder sounds are generally better liked initially. as producers, we want to be able to fairly assess exactly what we are doing to our tracks; it can be difficult to hear passed volume adjustments as various effects are applied and it can be difficult to compensate for this with an inverse gain adjustment because the changes in loudness are generally applied in a non-linear way.
enter my newest max device. as always, you can download on the devices page. let's have a quick look at how to use it:
start by mapping the x-axis knob (in the top right) to the same macro as your effect. in this case I'm using softube's excellent and free saturation knob.
notice how both the saturation amount and the x-axis of the mapME now move together with the macro knob. the y-axis will control the amount of gain added or removed at any given x-position.
I like to start by jumping to the end and making the subjective, perceived volume equal to that of the dry signal. the knob in the bottom right controls the scale of the y-axis (default is -20, 20). adjust this to whatever is appropriate for the amount of gain fluctuation you'll be dealing with. then, move to each node and compare it to the dry position and move the node until the volume is equal to that of the unaffected signal. once this is done, you'll be able to add the effect without having to worry about how the volume difference are affecting your perception of the timbre.
if you want to see this device put to use, be sure to check out my 'honest saturation' rack. a convenient effects group with 6 different saturators, all volume-compensated to give you a true idea of what you're doing to your sound with each of them.