[sdiy] Different pole notches and phasers

Tom Wiltshire tom at electricdruid.net
Mon Apr 13 12:58:32 CEST 2020

Hi all,

Could someone explain something I don’t understand clearly to me?

What does it mean to talk about the number of poles when discussing a notch filter?

Additionally, what’s the difference between a notch filter and a notch created with an allpass filter and the input added together? Is there a difference?

It seems to me there is, since multiple stages of allpass filters with the input added together (a phaser) creates multiple notches, whereas a multi-pole notch would just be a deeper/narrower notch. Is that right? Or could a 4-pole notch filter have two notches?

There’s something I don’t quite get here, and I’m struggling to find exactly what it is, hence the rather confused questions. Any clarification anyone can offer would be greatly appreciated.

       Electric Druid
Synth & Stompbox DIY

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://synth-diy.org/pipermail/synth-diy/attachments/20200413/e5c96215/attachment.htm>

More information about the Synth-diy mailing list