How can I learn to be able to code filters?

Nu Audio Science · 3 Jun 2005

You could try Tobybears filter Explorer.

Sorry i cant help more but i'm in the same boat, I can however point you to a lot of online DSP courses and so on ?

platinumears · 3 Jun 2005

broadly speaking there's two levels of filter design: the maths involved in implementing someone else's algorithm is not that hard (otherwise I couldn't do it!) .. actually designing a filter from scratch is much more difficult (way beyond me at the moment 🙁)

most of my basic filter knowledge came from the dsp guide, which you can download for nothing if you're short of cash, or only want the filter chapters..

Dan 🙂

Acolmiztli · 3 Jun 2005

Maybe I'll try implementing some algo's then first 😉

Rellik · 3 Jun 2005

What I did was just find some online tutorials and start reading...

It's not actually too complicated unless you try to think about it. Suggestion: don't try to think about what the filter is "doing" in the frequency domain through what it's doing on a sample-to-sample basis. At least for me, it just doesn't picture right... but it works!

I still don't know how to calculate co-efficients - and many algorithms are still pretty tough for me to understand - but I think I get the basics.

stefan · 3 Jun 2005

Actually, the z-transform ain't all too tricky if you try to learn that one. Then you can start designing your own filters with a pen and a paper (drawing frequency responses etc).

Been a while since derived filters from scratch, but I remember it as being quite logical 🙂

platinumears · 3 Jun 2005

Actually, the z-transform ain't all too tricky if you try to learn that one. Then you can start designing your own filters with a pen and a paper (drawing frequency responses etc).

Been a while since derived filters from scratch, but I remember it as being quite logical

Any chance of a walk through then..?

stefan · 3 Jun 2005

platinumears wrote: Actually, the z-transform ain't all too tricky if you try to learn that one. Then you can start designing your own filters with a pen and a paper (drawing frequency responses etc).

Been a while since derived filters from scratch, but I remember it as being quite logical

Any chance of a walk through then..?

I'd say that there are pages on the internet much more educational than what I'll ever be 🙂 I should take a look at some of them too, it'd be good to refresh the memory a bit...

platinumears · 3 Jun 2005

fair enough! 🙂 I finally got round to buying filter explorer... maybe I'll try to understand this z transform thingy again! (I'm starting to wish I turned up to more of my math lessons at school.. 😉)

Dan 🙂

Nu Audio Science · 3 Jun 2005

I'm starting to wish i bothered going to school 🙂

Shifrin · 3 Jun 2005

I found this invaluable when learning about digital filters (something I am still learning a lot about now - and probably for years to come!) :-

http://www.eumus.edu.uy/docentes/jure/docs/Niemitalo_DSPForTheBraindead.html

HTH

Shif.

skOre · 3 Jun 2005

AH! For the Braindead! Just my taste 🙂

kingtubby · 3 Jun 2005

Shifrin wrote: I found this invaluable when learning about digital filters (something I am still learning a lot about now - and probably for years to come!) :-

http://www.eumus.edu.uy/docentes/jure/docs/Niemitalo_DSPForTheBraindead.html

Fantastic link - Thank you! 😀

Mart.

Acolmiztli · 3 Jun 2005

Braindead? Hmmm... got anything a bit easier to understand? 😀

infuzion · 3 Jun 2005

kingtubby wrote: Shifrin wrote: I found this invaluable when learning about digital filters (something I am still learning a lot about now - and probably for years to come!) :- http://www.eumus.edu.uy/docentes/jure/docs/Niemitalo_DSPForTheBraindead.html

Fantastic link - Thank you! 😀

agreed; WiKi'd

Shifrin · 3 Jun 2005

Acolmiztli wrote: Braindead? Hmmm... got anything a bit easier to understand? 😀

That's about the easiest filter paper I've ever found to be honest. I think when it says braindead it actually means people who have a good grasp of mathematics but perhaps not quite at degree level 😉 Braindead indeed!

Shif.

infuzion · 3 Jun 2005

Shifrin wrote: I think when it says braindead it actually means people who have a good grasp of mathematics but perhaps not quite at degree level 😉

Can't have wavy lines w/o trig! [old link]

Acolmiztli · 3 Jun 2005

Shifrin wrote: Acolmiztli wrote: Braindead? Hmmm... got anything a bit easier to understand? 😀

That's about the easiest filter paper I've ever found to be honest. I think when it says braindead it actually means people who have a good grasp of mathematics but perhaps not quite at degree level 😉 Braindead indeed!

Shif.

lol.

platinumears · 3 Jun 2005

thats the problem I always have: whenever i start to try to understand filter design I seem to transmute from above-average intelligence to 'sub-braindead' 🙁

Acolmiztli · 3 Jun 2005

platinumears wrote: thats the problem I always have: whenever i start to try to understand filter design I seem to transmute from above-average intelligence to 'sub-braindead' 🙁

You mean you keep aliasing... right?? riiiggghhtt??

platinumears · 3 Jun 2005

Stability seems to be the real problem.. 😉

Filter explorer is very cool though: if I can't get to grips with it with that I probably never will!

Dan 🙂