FabFilter User Forum
Filter always saturated?
After using FFT for a few months, I've started to notice that the filters (or at least the resonance path for the filters) always sound saturated/overdriven, regardless of filter algorithm (although it seems that the type of saturation/asymmetry is different for each algorithm).
This is usually a nice sound, it gives Twin warmth and character. However, it is not always the desired sound. One of the advantages of Twin is that it is so smooth all around. Thus, it would be nice to include a filter that is truly "clean", or better yet to have the saturation amount dependent on the input level to the filters for every algorithm. The second option is preferable because it would add a dynamic component to the saturation when e.g. the osc levels are modulated. So for example, it would be possible to program a patch where the filter just starts to really growl at the crest of an envelope (target osc level) transient, and smooth out as the envelope decays.
Please consider for a future update. :)
It seems to me (if I'm not imagining this) that the saturation amount *is* dependent on the input level. I'll sometimes cut the osc level(s) back as much as -9dB in order to get a cleaner sound from the filters. If you trim the oscillator much more than that you can't compensate effectively with gain at the amp stage, but even with this limit it seems like a useful technique.
Here's a comparison -- same patch, first with the oscillators at full, then with them trimmed -9dB and a compensating boost in the amp. (Both halves are normalized; no other post-processing.) glitchpop.net/bbl/paulsc/vary-osc-lev-into-filt.mp3
PaulSC is right: the sturation level is dependent of the filters input level. So if you put the oscillator levels down, and the overall level up, the filtered sound will be quite different.
It's true that the included filter characteristics aren't superclean, but that's actually what we like about them :-)
I'll try to create a super-clean filter characteristic...
Cheers,
ah, by the way, Claude: what you suggest, is routing the filter -after- the main envelope generator... Indeed, this would result in a quite different sound. However, the EG needs to be routed after the filter, otherwise you would hear the filters constant self-oscillation when using high resonance....
And again, Claude's second suggestion can already be done by routing the envelope to each oscillators independent volume knob.
Cheers!
PS. I'd also like to hear a "super clean" like filter.
Okay, I'm mildly embarrassed and a bit confused. Turning down the osc levels does indeed induce the desired behavior. I swear I tried that before and it didn't seem to do anything, but now it works a treat.
Hmm...is there any reason that might occur? In my host, the meters didn't show that the signal was clipping or anything.
As bmanic already clarified, I wasn't suggesting that the VCA stage go before the filter, that part wasn't actually a feature request at all - I was just describing a patch where a filter that gradually goes into saturation would be preferable (by adjusting the osc levels into the filter with an envelope). But this can already happen. :)
And it's a nice effect indeed! It inspired me to make a preset with it (Organic FL.ffp); added it to the extra Twin presets on the support page!
Cheers,
Nice preset Floris!! It inspired me to create two variations:
cmt.siba.fi/nisilen/Two_Organ_Presets.zip
Have fun!
Nice! Added them to the Extra presets on the support page :-)