FabFilter User Forum

Range Parameter on Pro-C2 & Pro-MB

Hi,

According to the manual, the range parameter sets the maximum amount of GR.
It really does, but it also changes the way the compressor reacts.

For example, when the 'Range' is set to maximum (30/60 dB), I get a total GR of 6 dB.
When I lower the "Range" to 8 dB,theoretically, I should get the same amount of GR, But I don't.
It like the amount of compression is "compressed" according to the range

I guess this is on purpose?
If so, it would be really helpful to add this to the manual, and maybe explain about it a bit.
Also, it would be great if I could choose that the range knob would be only a GR limiter, like it's described in the manual.

Cheers

Yroth

Hi Yroth,

In Pro-C 2, Range is actually very simple: it just limits the measured amount of gain above the threshold (before smoothing it with attack/release). This is also visualized in Pro-C 2's knee display (the transfer curve).

In Pro-MB's normal, downward compression, or upward expansion modes, the exact same way of applying Range is used as in Pro-C 2.

However, for Pro-MB's upward compression and downward expansion (gating) modes, Range is applied in a different way. In this case, it actually scales the detected gain below the threshold, which feels much more natural than limiting it.

Hope this helps!

Floris (FabFilter)

Hi Floris,

I understand the concept, and the knee display does visualize this very well.
But I have noticed that when the compressor's GR is close to the limit of the 'range' it reacts a bit differently than described.

This is how you can reproduce this "issue":

Take any wave (in my case, I took a full mix and looped a small part of it), and set the threshold to a point that you get around 8.5dB of GR, while using the full range (60db).

Now take the range down to 9dB, you will see that you now get lower amount of GR.
My point is - if you only got to 8.5dB GR earlier, why does the range of 9dB change the amount of GR?
8.5dB is still in that range, and should not be affected
Note that this only happens when you get close to the range amount.
(8.5dB GR in a 9dB range)
If I had changed the range to 12dB it wouldn't matter if it's 60dB or 12dB of range.
I guess there's some sort of knee for this range? so when you get close to the limit of the range it does lower GR in a way?

Hope I was clear about it :}

Anyway, this only came up as an issue for me because I noticed that if I set the range parameter to a more relevant one, the "auto-gain" works more accurately.
When range is set to 60dB in Pro-C2, the auto-gain usually gives a lot more gain than needed (which is also something you might wanna check)
When range is set according to the amount of GR you need, auto-gain really nails it.
But again. you need to give a range a bit of "headroom" for it to work the same.

I'd be glad if you could check this out and tell me if what I'm saying is right, or I'm doing something wrong.

Thanks a lot !

Yroth

By the way, in Pro-MB it's even "worse".
Whenever you change the 'range' parameter, the amount of compression is obviously changed.
So I don't understand how Pro-MB uses the exact way as Pro-C2, as you say.

Yroth

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