Selectable auto Makeup Gain in Compressor

unix-guy

unix-guy

Master of RTFM
With the recent updates to the Compressor block in FW18.03 (and FM9 FW 2.0 beta), we got auto makeup gain added to a number of the models:

FractalAudio said:
The Pedal, Optical, Tube, Analog, JFET and Dynamicomp types have been completely redone resulting in improved performance. These types now inherently perform automatic makeup gain.
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It would be cool if we could optionally disable the makeup gain in these models.

I have built a number of presets where I used the JFET or Optical Compressor models (at the beginning of the signal chain) with the Level at 0 and mix less than 100% (usually around 60%) with a fairly low Compression setting (2-3).

I can't seem to get the same response (which makes sense) after this update. If I change nothing then I'm getting a signal that's too hot for what I want. I tried lowering Level to -3dB - -6dB and that helps but still doesn't seem the same, and then it's also the same for every note...

I'm hoping we could have a simple selectable option to bypass the auto makeup gain. I have no idea how difficult this would be to implement.
 
Makeup gain is a fixed gain that’s present whenever the compressor is engaged. It can be modeled exactly with the Level parameter.
 
You should be able to get the old sound by adjusting the block level. But, there is probably no simple way to determine what that value should be by inspection of the parameters. That does seem like a curious decision to break existing presets like that. An on/off switch for makeup gain is pretty common these days.
 
unix-guy said:
I know you said similar here but I have to think it's more complicated than that based on a few related posts:

https://forum.fractalaudio.com/threads/axe-fx-firmware-release-version-18-00.179261/post-2186729

I feel like if it was as simple as that then why not just leave it as it was (and let people use Level to deal with it if they wanted)?

Or if it is that simple, how can I figure out what Level I should use to match the previous behavior?
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Seriously, Makeup Gain is just a fixed change in output level for the Compressor block. It doesn’t change the behavior of the compressor in any other way.
 
Rex said:
Seriously, Makeup Gain is just a fixed change in output level for the Compressor block. It doesn’t change the behavior of the compressor in any other way.
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To put it another way, Makeup Gain is there so you don’t get a drastic change in level when you bypass the compressor.
 
I'd expect Auto Makeup Gain to calculate a fixed amount of gain to apply based on the settings you're using. For instance, it would add very little gain if your ratio is low, but more if it's high.

It's trying for roughly unity gain in total. It can't really do that without knowing how loud the input signal will be, so it's an approximation, but I think that's the intent.

Is that not what it does?
 
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Dave Merrill said:
I'd expect Auto Makeup Gain to calculate a fixed amount of gain to apply based on the settings you're using. For instance, it would add very little gain if your ratio is low, but more if it's high.

It's trying for roughly unity gain in total. It can't really do that without knowing how loud the input signal will be, so it's an approximation, but I think that's the intent.

Is that not what it does?
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That’s what it does, except for the “unity gain” part. Bringing a compressed signal to unity gain would require an expander.
 
Rex said:
Makeup gain is a fixed gain that’s present whenever the compressor is engaged. It can be modeled exactly with the Level parameter.
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Only when using the compressor at 100% mix. When trying for the parallel compression trick, it falls apart, unless you add a mixer block and parallel shunt, which kinda defeats the porpoise of the mix knob....
 
Bakerman said:
That is what it does.

You'd need to reduce mix and level to match a previous sound that had mix below 100%. (I'm assuming makeup gain is applied to the wet signal only, like the Axe II studio compressor type.)
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Per Cliff, the Auto Makeup shoots for a medium HB output level, which may be louder or quieter than needed.

For 100% wet, it is a no-brainer to just adjust the output level where you want it, but it is less obvious what to do when mixing the compressor with the unprocessed signal.

A block diagram of where the auto makeup and output level controls are in the signal flow might help elucidate how to make it work with the new goodies.... 😊

All of that said, I think a selector for -12dB, -6dB, 0dB, +6dB, and +12dB to adjust away from 'medium HB' output level would be helpful for a lot of people. A lot of the compressor plugins in Logic have buttons for auto-makeup at multiple levels of output, so it is at least precedented and moderately familiar....
 
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It can't be turned off because it's inherent in the algorithm. Think about the classic Dynacomp. It doesn't calculate the makeup gain, it happens automatically due to the nature of the circuit. The algorithms replicate the behavior of the circuits.

I don't understand what is so confusing. You turn up the compression as desired. Play a bit. Bypass the block. Now engage it. If you need a bit more output level turn the level up and vice-versa.
 
GlennO said:
You should be able to get the old sound by adjusting the block level. But, there is probably no simple way to determine what that value should be by inspection of the parameters. That does seem like a curious decision to break existing presets like that. An on/off switch for makeup gain is pretty common these days.
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For those types where it is possible to turn off makeup gain a switch IS provided.
 
FractalAudio said:
It can't be turned off because it's inherent in the algorithm. Think about the classic Dynacomp. It doesn't calculate the makeup gain, it happens automatically due to the nature of the circuit. The algorithms replicate the behavior of the circuits.

I don't understand what is so confusing. You turn up the compression as desired. Play a bit. Bypass the block. Now engage it. If you need a bit more output level turn the level up and vice-versa.
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Thanks for the reply.

In my case, I dialed things in with Level at 0 and Mix at 60%. I guess I'll just have to keep trying to get back to where I was before by lowering Level until I find the magic value where it's not pushing the Amp too much.
 
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