Hey, I’m by SA standards a pretty novice user. I’ve been working really hard to teach myself synthesis and I’ve got what is probably a dumb question that I have not been able to figure out the answer to.
I am trying to figure out the relation between the big Filter 1/2 knob when used in conjunction with Filter 1 and or 2.
Let’s just take a run of the mill saw wave. Assume only Filter 1 is active. Filter 2 is out of the equation.
If Filter 1 is on low-pass, and you set the cutoff frequency in ANA to 60 hz, and the Filter 1/2 is set at 1 hz, the sound is significantly modified.
If you change the cutoff frequency on Filter 1 to 1 hz, and then you change the Filter 1/2 cutoff to 60 hz, the sound is identical. This stands to reason as the sound is passing through the same level and type of filtration.
What I’m having trouble understanding is that if you leave the Filter 1 cutoff at 1 hz, and you leave the Filter 1/2 cutoff at 60 hz, the sound is affected when either knob is turned. In theory, one of the controls should be redundant…one of these controls is rolling off frequencies higher than 1 hz…although I can’t tell which one. Whichever of the two controls is rolling off frequencies higher than 60 hz should have no effect, because the control specifying filters higher than 1 hz should have no effect, because those frequencies have already been filtered out.
That is not the case, however, because when you turn either of the two knobs, the sound is adjusted.
This means that I’m not understanding something about how the two controls work in tandem, and I’m guessing it’s something resulting from my noviceness.
So that said, let’s just assume this same context - only Filter 1 is on. Filter 2 is off. Parallel vs. serial doesn’t matter in this context. What is the big Filter 1/2 cutoff knob doing to the wave that the Filter 1 cutoff knob isn’t and vice versa?
Thanks,
Neil
The big filter knob just modifies both filters at the same time.
The way it shows frequency on the control info is a bug… it should show an arbitrary number from 1-10 or similar.
hi guys im in the same boat here new to sound design i felt i could gain alot from taking the time to learn how to hear a sound and try and replicate things. Im using ANA and the videos to get the basics but i too am struggleing to understand what the big filter knob’s job is. If u have already applied a low cut off in filter 1 how can the big filter knob then increase the sound ? How i see it the sound is already taken away therfore its sort of confused the situation with how the filter amp env works. If the big filter knob did not exist everything would make perfect sense but bcuz it does and it never seems to get explained on any videos id greatly appreciate ur help. br
br
Im shur im over thinking it but any quick advice would be greatly appreciated. Thanks guys
Just spent some time trying to figure this out myself, and thought I’d post an answer in case anyone else finds themselves scratching their head. In my below explanation f1 cutoff refers to the actual filter cutoff, and CUTOFF refers to the big filter shared knob CUTOFF 1/2.
The reason the filter interaction is confusing is that it’s seemingly non-symmetrical. What am i mean is this:
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If you turn the CUTOFF all the way to the right (max), it will completely override the filter 1 cutoff. Notice how you can turn the f1 cutoff knob and there is no effect on the sound when CUTOFF is at max.
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However, if you turn the CUTOFF knob to min, then the f1 filter knob is unaffected by the CUTOFF knob. Now you can turn the f1 cutoff knob and have complete control over the sound.
This all seems rather non-intuitive since when turned to max, the CUTOFF knob completely over-rides the f1 cutoff. And when turned to min, the CUTOFF knob has no affect on the f1 cutoff.
Even weirder, when CUTOFF is at the default position of half-way, the f1 cutoff knob seems to override CUTOFF when turned less then half-way (left half of knob), and is overridden by CUTOFF (ie has no effect on the sound) when turned over halfway (right half of knob). And when both are turned half-way, you get a very different sound then if CUTOFF is at min and f1 cutoff at halfway. So they are summing together when both of them are at half-way.
And actually this is the answer to the mystery. The filters actively sum together. So when both are half-way, you get a fully open filter. If one is min and the other half-way, you get a filter at half-way. Because the scale of the filters is logarithmic, think in terms of the knob percentage instead of hz when summing them in your head.
In my opinion it would be much more intuitive if the f1 knob had full control when CUTOFF was at max, and no control when CUTOFF was at min. Then the blue highlight of the CUTOFF knob would define the active range of the f1 cutoff knob.