I'm using the Web Audio API to make a graphic EQ with four BiQuad filters; a highpass, two bandpass and a low pass:
You can see each node representing each filter's frequency. It's working nicely but I'd like to draw the shape of the filter's roll-off you'd usually find in other graphic EQ's.
I have the Q-factor of each filter and the central frequency. What I would like to do is get a formula that allows me to get the frequency of the roll-off at a specific db value. For example what is the frequency of the roll-off at -200db?
It's been a while since I've done any heavy mathematical stuff and so any help would be greatly appreciated.