FabFilter User Forum

Pro L2 Threshold

Hi,

I'm a little bit confuse on the way this limiter works. I'm used to have an output setting and an treshold setting, here on the Pro L2, from what i'm reading, the two are linked.

So if i just want to set an TP celling without changing the overall gain of my mix let's say to -3db TP. I've to set the input gain to +3db and the output gain to -3db right ?

if this is right, i'm a little bit worried about the gain stage. If Pro L2 is boosting my mix then limiting it then lowering the final output, doesn't it make it limiting more than it was needed ?

On a busy part of the mix with an average level at nearly -3db, the +3db on the input will make this part go above -3dbTP thus triggering the limiter.

Am i understanding this correctly ?

Best.

Guillaume

Hi Guillaume,

Yes you're understanding it correctly. You should set the desired ceiling level with the output level in Pro-L 2, in your case to -3 dB. Then you adjust the gain to make it as loud as you want -- if you want to keep the existing gain you should use +3 dB.

Cheers,

Frederik (FabFilter)

Hi,

Thank you for your reply ! But what about my concern? Doesn't the +3dB on the input put some part of the mix above the threshold ?

Best.

Guillaume

That's basically how a limiter works. How would you imagine should it work, if it has to compensate your 3dB reduction?

If you just want -3dBTP then set the output gain. This doesn't change the overall Peak-To-Loudness ratio of your track.

Boosting the input will make Pro-L2 probably process. Same like using a dedicated threshold slider in other limiters.

Mirko

hi,

Thank you for your time. I see your point but this confirm that this wonderfull tool maybe isn't the right one for my needs.

When i mix content that need to follow the loundness recommandation (EBU R 128) for TV by example. I mix in order to be around -23dbFS Integrated. I'm only using a TP limiter on my master to catch the randoms peaks above -3dbFS that may occur.

I dont want my mix to be 3 dB lower nor it to be boosted then limited. I just need a limiter that cut any peaks that goes above a certain level that i choose. Like on any limiter.

Cheers.

Guillaume

Then that's exactly what you get when you increase the input gain and Pro-L has the right behavior ^^

Imagine Pro-L has a fixed limiting threshold at 0dBFS. But you want it to limit anything above -3dBFS. So instead of pulling a threshold slider down to -3dB, you could increase the input by +3dB. That is the same thing. But if you increase the input by +3dB, the output has to brought down by 3dB again. Btw Pro-L has a nice gimmick for that: increase the gain while holding alt - it will then decrease the output gain automatically.

That's how you limit at -3dB and you were doing it right. And it does not limit anything else. Just take a look at the gain reduction meter and compare it to any other limiter or create a small test case.

Mirko

I agree with Mirko. There is really no difference between Pro-L 2 and a limiter where you set a -3 dB threshold level: the end result is the same, only the controls are different.

Cheers,

Frederik (FabFilter)

Hi,

Thank you both for your time and forbearance ! And thank you Mirko, your last reply finaly made me realise my mistake. I was thinking that the threshold was set by the gain slider somehow thus modifying the peak-to loudness ratio, what a fool...

Best.

Guillaume

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