FabFilter User Forum
Pro Q4 not acting consistent.
Just wanted to tune into this thread saying we're in touch with this issue over email.
Sorry, but I really need to ask:
Is this an isolated issue, or should I/we be concerned?
Good to know before I fill projects with Pro Q4's.
We're investigating this issue, but it appears to has to do with a reset function provided by the host. When you start playback, the host will give a reset function to all plug-ins, basically giving the plug-ins a start point for their processing so it's always in sync. This way the block size used for the processing will always start at the same spot in the wave file, which would give similar processing.
However, when in loop, this start point is only given at the start of the playback, not every time the loop starts at the beginning again. So when you loop a certain section, the block sized are divided differently over the audio file, which can lead to slightly different processing. We offer some smoothing between block sizes to minimize this effect, but it is possible that you will get slightly different results on each loop.
Additionally it seems that Avid does give a reset notification with offline bouncing, but not when online bouncing. This means that when you're bouncing only, the block sizes could start at a slightly different point every time, which might lead to slightly different processing.
This is not a huge deal in most situations, but it might show different spectral processing when in loop mode.
Hi.
I have a persistent issur with Q4 operating spectral mode.
Full automation on protools 2025.12 and or 2026.4
The delay compensation doesn't apply correctly each time you hit play.
Sometimes it is right, sometimes it is wrong.
Are you aware of this?
We're not aware of this. Can you send us a small video of the issue along with a test session to info@fabfilter.com?
I’ve noticed with pro Q4, when I have a dynamic EQ set and have it in spectral mode, that it doesn’t always do the same thing at the same point in a song. For instance, I can run a vocal through it and on each bounce it is doing different things at different time. It’s subtle, but when I’m trying to just knock out a few harsh frequencies when they crop up and have it sounding good, I can literally loop a few bars and it cuts them only sometimes.
I can even take a kick drum sample for instance, paste it on the downbeat of every bar in a song put a dynamic EQ with a low shelf to reduce 2-3DB below 80 Hz, and with that same sample hitting the pro Q4 throughout an entire song, I can watch the pro Q4 sometimes not do a single thing for a few bars and then the next bar do the dynamic eq on some frequencies. Is this a bug or was this thing designed to be inconsistent?