EQ Distorts Sound

startec's icon
Max Patch
Copy patch and select New From Clipboard in Max.

Hi All, Here is a 15 band EQ I made. It works almost exactly the way I want it to but for some reason, when I turn it on it distorts (makes louder) the sounds. Does anybody have an idea how I can make sure the songs sound the same when the EQ is on (and all frequencies are set to 0 db)?
Thanks

LSka's icon

Hi startec,
the distortion happens because resonant filters introduce distortion for their nature. You can try to reduce the volume boost reducing the filters' gain and increasing the Q factor, so the various bands don't overlap too much.

You may also have a look at the fffb~ (fast fixed filter bank) object, which does pretty much what you are doing, (there's also an example patch with a 3d-of-octave-band EQ in the 'examples' patch) or use the filtergraph~ object to have a visual reference of how the eq's affect your signal.

Peter McCulloch's icon

I recommend the crossover network that I posted in the other thread on this. It'll sound way better and you don't have to futz with resonance.

If you want a steeper rolloff when using a reson~ filter, however, I recommend using more than one reson~ in serial (each with the same settings). This sounds way better than just increasing the Q, as it gives you double the rolloff rate. With this trick, you can use a lower Q, but still achieve a steep rolloff. (this is known as a higher-order filter, since you're stacking biquads; you can see how this looks using filtergraph with multiple copies of the same bandpass filter)