creation date: 2025-01-17 10:10
modification date: 2025-01-17 10:10

Infinite Impulse Response Filter (IIR Filter)
IIR Filter Graphing Tool

Feedforward Filters

Feedforward filters generate one or more zeros

Feedback Filters

Feedback filters generate one or more poles

https://www.youtube.com/watch?v=ap1qXBTKU8g&t=442s

Pole Zero Filters

Usually these will be combined to create a p-z filter (pole zero filter)

because the filters are linear and time-invariant, the filters can be switched around like this:

each filter can share the delay feedback path like this:

Direct Form 1

Direct Form 2

Bi-Quad Filter aka 2nd order IIR Filter

extensively used in audio DSP, very computationally efficient

Cascade them to form a

4th order IIR Filter

FIR filter, compared to IIR filters, are more computationally expensive and require possibly hundreds of taps to achieve the same goal. because of the hundreds of taps, very high latency. They can only be computed in the digital domain while IIR filters do not have this limitation

Tags

#DSP