FabFilter

I'm trying to mix a track for CD so I don't want to go past -9 LUFS. So I want to put a ProL2 right at the end of the master bus and use a brickwall setting so it never goes louder than -9 LUFS no matter what level hits it. Basically infinity to 1. But I don't see a way to archive this automatically even if I change the look ahead. I seem to have to lower the output gain to try and make sure it doesn't pass above this volume.

I could play the whole track back with the build up visualization and then manually reduce the output gain based on the loudest peak, but isn't there a way to just set the L2 so it reduces the level so it never goes above the -9 LUFS? Maybe I have the wrong idea of how a brickwall limiter should work.

Thanks for your input!

I think you may be confusing LUFS (average perceived loudness) vs. dBTP (true peak level). With ProL and most other limiters you can easily set a dBTP ceiling so your waveform never exceeds that ceiling. You do that in ProL by adjusting the Output knob in the lower right.

LUFS is a different kind of thing. It's not as simple as just limiting the waveform peaks when they try to exceed a ceiling. LUFS is more like a standard way to judge average perceived loudness over a time window of long, medium, or short duration, so it's also kinda measuring dynamic range, with (for example) -5 LUFS being squashed to very little dynamic rage and -14 LUFS having more dynamic range in return for lower average perceived loudness.

ProL doesn't allow you to set a number for LUFS and have the limiter automatically achieve that. I don't believe I've ever used a limiter plugin that allows that to be automatic. Instead you can adjust LUFS metering settings and meter it and then adjust limiter settings how you like according to your own opinions of what sounds good and how much distortion you're willing to tolerate to get higher average perceived loudness. I'm usually trying to get the loudest part of a song to hit a specific Short Term LUFS value, but I'll only push LUFS as loud as I can while avoiding nasty sounding distortion.

Ah, that makes a lot of sense! I understood LUFS to be an average perceived loudness but that you could still mix to it the way you would to dB. I looked at the tooltip for the output gain knob in the lower right and see exactly what you are saying. That clears up a lot! Thanks for the explanation :) Cheers!

So am I correct in understanding that in order to make sure a track doesn't clip on a cd the dBTP should probably be -0.1? Then the LUFS target is really just the preferred loudness I want to go for independent of clipping so even if that goes a little above -9 on peaks sometimes it won't cause clipping on the CD as the output gain knob is set to -0.1 dBTP (and ProL won't let a signal above that through)?

Thanks again, really appreciate it!

Actually I'd set the L2 output to -.5 so you have better margin. L2 isn't all that great as a brickwall limiter even when true peak limiting is engaged. I sometimes end up putting the Sonnox limiter after L2 with the Sonnox acting as a brickwall limiter.