Arbitrary Group Delay Filter Design Specification

Hi there,

I've tried asking this before, and never got an answer. I've changed my question somewhat so here it is:

I want to create an arbitrary group delay filter so that I can achieve the following delays at the following frequencies:

I've tried using the filter design tool several times, but the delay calculated (even with just an order 2 filter) is higher than expected. What can I do to realise this filter in MATLAB???

Many thanks!

Answer 1

[Mathieu NOE]

Hi

If I were you, I would design multiple parallel bandpass filters centered on the octave or 1/3 octave frequencies (for refined treatment)

(NB the time sum of all filtered components equals the original signal)

at each individual bandpass filter I would just add the right amount of sample delay to match your specs

some this solves your problem

[Mark Thompson]

Hi, Mathieu,

Thanks for your suggestion there, that is something I have already looked at. I'm looking for a bit more prescriptive control, per frequency, over a given bandwidth rather than a fixed delay for all frequencies within a filtered region. So I appreciate the intent of your response, however I'd still like some assistance from the Mathowork folk regarding how to actually use their Arbitrary Group Delay filter to achieve my goal.

Cheers!

[Mathieu NOE]

hello Mark

so you already tried with

https://www.mathworks.com/help/dsp/ug/iir-filter-design-given-a-prescribed-group-delay.html;jsessionid=667d05ce3d0cb3dd0f7a18a29788

?