https://journals.aps.org/prb/abstract/10.1103/PhysRevB.99.024302 https://journals.aps.org/prb/abstract/10.1103/PhysRevB.99.02... Like you said, it’s not wideba

https://journals.aps.org/prb/abstract/10.1103/PhysRevB.99.024302 https://journals.aps.org/prb/abstract/10.1103/PhysRevB.99.02... Like you said, it’s not wideband. This implementation is a notch filter about 50Hz wide. Interesting if you’re looking to reduce a specific source, which can happen. For example to cancel fan noise.