Rendering a file with a high latency plugin bug?

When rendering a file containing a plugin with a high latency (DMG Equilibrium, Fabfilter Pro Q in linear phase) in the master section then the audio in the rendered file is shifted forwards. the amount varies depending on the latency on the plugin. The audio length of the rendered file doesn’t increase so the tail of the audio can be cut off if there isn’t much silence at the end. This is a major pain! If I switch the plugin to a zero latency mode (if it has one) then the problem goes away. Is there a bug in the plugin delay compensation?

Delay compensation is obviously something that is implemented. There is no known bug, but the plugin notifies WaveLab of its internal delay.

Just tried Fabfilter Pro Q 2 in linear phase and there is no problem (Windows, WaveLab 64 bit).

I am also running Fabfilter Pro Q 2. Mac / Mavericks. if I have the plugin running in zero latency mode then there is no issue. If I run the plugin in maximum linear phase then the audio in the rendered file has shifted forwards around 1.5s. If I run DMG Equilibrium in Analogue mode at full impulse length then the resulting rendered file has shifted forwards 3s. If I use zero latency mode then there are no issues.

You are right, in Linear Phase, there is a delay. You should notify this to Fab.
If you take another plugin with high latency, such as Voxengo CurveEQ, you won’t get that problem.

I’ve contacted Fabfilter who are going to try and replicate the issue and fix. I contacted DMG back in May about the same issue happening with Equilibrium but as far as I’m aware there hasn’t been a fix yet. Wavelab seems to obtain the plugin latency from plugins slightly differently to other DAWs

FabFilter just released an update for Pro-Q 2:

A simple test tone test seems to show that the problem is solved.

Track 1 is the original source and track two is the rendered WAV which seems to match perfect: