Does the autofilter add in DB?

[1pauluzz1]

First of all I'd like to say thank you to Ableton for really doing an excellent job on fixing bugs. I had some problems with crashes and freezes before, but within 2 updates all my problems were solved and I never had a crash even since (knock on wood).

This is not really a problem, just a question I'm curious about: I just loaded a song that is mastered to the roof, so it fills up exactly to 0 db (it also sounds excellent so I applaud the mixing here).

When I load an autofilter in the channel, the tracks starts clipping to points that go even 3 db in the red. This is the same for every envelope, attack, release or filtermode-setting, with the Q turned all the way down at all times.

How is this possible? If I turn the track 3 db down the signal stays under the limit; is it just me or are there more people who think it is strange that when I lowpass a track, I'm confronted with a rise in volume?

Thanks for the explanation

[1pauluzz1]

So no-one has ever experienced this before, or is willing to test it out?

[matt1230]

This is probably because you have the resonance set to anything but 0 which means you are adding volume around the cutoff point.

[1pauluzz1]

Nope, in all cases the resonance Q is 0.

[0fps]

Is there any LFO active maybe?

[1pauluzz1]

No. The same happens if I try it with an eq8, so this is likely "normal" audio behavior. But I'm very curious about the theory behind it..

Cutting away the bassregion (or any frequency band in the spectrum for that matter) shifts the balance in the track and thus other frequencies have more space to peak..? Something like that?

[1pauluzz1]

Thanks for your analysis. You are right; the autofilter does automatically add something since the Q is at the lowest 0.20.
I'll have another go with the eq8; with this theory it shouldn't be possible but I did in my case.