FabFilter User Forum

L2 External Sidechaining not working properly


I have to deliver mastered stems so I'm trying to have L2 limit the stems whilst being triggered by a printed (un-limited) full mix. But, unfortunately L2 just seems to stop working properly as soon as I enable sidechaining. I can see it react to the full mix but It's letting peaks through like there's not even a limiter there and seems to just be responding completely different with sidechaining turned on.

I'm using Studio One Pro 5 by the way.

Hope there's somebody out there that can help me :(




I'm sure you thought of this, but to be sure, are the Pro-L2 instances for the stems inserted post-fader?


Hey Bram,

Thanks for the reply!

Yeah, the L2 instance is on the main output's post fader and the printed (unlimited) mix's output is routed straight into the L2 stereo sidechain input, unaffected by any other type of processing.


Same problem here using Pro Tools. Have anyone figured out a way to make the side chain work correctly?


Pro Tools still only supports mono side chains, so there is no way to make stem limiting work correctly, unfortunately.


Frederik (FabFilter)

Wouldn’t down mixing to mono the unlimited full mix work? 99% of the people I know that are working in audio post are doing it on pro tools. Exporting stems for clients is a regular thing for us.

Stem limiting would be awesome and as of now pro-L2 is the only plugin promising to do it.

Aren’t you guys able to do something about it? Maybe a little tweak for the AAX version?


I have the same issue with sidechaining on Logic Pro X as described in 1st post. However, it works fine on Ableton Live. So I export stems in Ableton Live))

Ansar Ismagilov

Hi guys,

there was an issue with the delay compensation of side-chain signals inside logic. However, this has been resolved with the 10.6.3 update that was release last week.


Ralph (FabFilter)
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