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Synths with 12db Low Pass Filter

Posted: Mon May 03, 2021 10:26 pm
by ryankm
I wanted to make this topic to talk about 12db low pass resonant filter on many availible poly synths...

They come in many various names and forms such as: State Variable, 2 pole, and Steiner Parker.

I was wondering what you alls experience was/is with them. I have a Fender Chroma Polaris and I think it is very well done. Powerful and can get pretty sparky...

How would it compare with others such as the Korg Proluge, Polybrute, or Moog One evan.

Ive heard MKS 80 and it has this spark brute charachter that sounds good. Are the modern couterparts abel to compete with their vintage parents?

Re: Synths with 12db Low Pass Filter

Posted: Tue May 04, 2021 2:06 pm
by meatballfulton
2 pole = 12dB/octave, it's a description of the filter's rolloff behavior. Each pole added to a filter adds another 6dB to the slope.

State variable, Parker/Steiner, ladder, etc. are types of filter designs. They can be any number of poles. The more poles, the more extreme the reduction of frequencies outside of the pass band, so for a LPF a 2 pole filter sounds brighter than a 4 pole because the rolloff of highs is less steep.

Many modern synths allow the filter to operate with multiple numbers of poles. It's very common to see both 4 pole and 2 pole operation, but in digital synths I've seen 1, 2, 3 and 4 pole options for the filter.

People argue endlessly about filter designs, usually over weird behaviors like the "squelch" of the Roland TB-303 or the uncontrolled behavior of the Korg MS20 filters at high resonance. Other than the filter, it's hard to find much of interest in a 303!! In the end it's just a matter of taste.