[Csnd] Simple Second Order Lowpass Filter Formula

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[Csnd] Simple Second Order Lowpass Filter Formula

epalaima
Hi, I'm doing some audio programming in C, and I'm looking for a simple 2nd order lowpass filter design I can implement. Not looking for anything too fancy, just need something like the Tone opcode but with a steeper cutoff. I was looking in the Audio Programming book but it only covers 1st order IIR filters. 

Any suggestions?

Thanks! 
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Re: [Csnd] Simple Second Order Lowpass Filter Formula

Richard
Have you checked the DVD chapters in the book? I did a chapter on
digital filters covering 2nd-order schemes, most especially the Robert
Bristow Johnson recipes, with example implementations.

Richard Dobson


On 17/02/2017 04:10, Emmett Palaima wrote:

> Hi, I'm doing some audio programming in C, and I'm looking for a simple
> 2nd order lowpass filter design I can implement. Not looking for
> anything too fancy, just need something like the Tone opcode but with a
> steeper cutoff. I was looking in the Audio Programming book but it only
> covers 1st order IIR filters.
>
> Any suggestions?
>
> Thanks!
> Csound mailing list [hidden email]
> <mailto:[hidden email]>
> https://listserv.heanet.ie/cgi-bin/wa?A0=CSOUND Send bugs reports to
> https://github.com/csound/csound/issues Discussions of bugs and features
> can be posted here

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Re: [Csnd] Simple Second Order Lowpass Filter Formula

epalaima
No, I had only looked in the book itself. I will be sure to take a look at that chapter on the DVD. Thanks!

On Fri, Feb 17, 2017 at 5:25 AM, Richard Dobson <[hidden email]> wrote:
Have you checked the DVD chapters in the book? I did a chapter on digital filters covering 2nd-order schemes, most especially the Robert Bristow Johnson recipes, with example implementations.

Richard Dobson



On 17/02/2017 04:10, Emmett Palaima wrote:
Hi, I'm doing some audio programming in C, and I'm looking for a simple
2nd order lowpass filter design I can implement. Not looking for
anything too fancy, just need something like the Tone opcode but with a
steeper cutoff. I was looking in the Audio Programming book but it only
covers 1st order IIR filters.

Any suggestions?

Thanks!
Csound mailing list [hidden email]
<mailto:[hidden email]>
https://listserv.heanet.ie/cgi-bin/wa?A0=CSOUND Send bugs reports to
https://github.com/csound/csound/issues Discussions of bugs and features
can be posted here

Csound mailing list
[hidden email]
https://listserv.heanet.ie/cgi-bin/wa?A0=CSOUND
Send bugs reports to
       https://github.com/csound/csound/issues
Discussions of bugs and features can be posted here

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Re: [Csnd] Simple Second Order Lowpass Filter Formula

Russell Pinkston-3
In reply to this post by epalaima

The Csound reson and butterworth filters are all 2nd order, so you can check them out in the sources.

 

But if you’re looking for simple C code, not tied to Csound, I’ve found this book useful: “C Language Algorithms for Digital Signal Processing” by Paul Embree:

 

https://www.amazon.com/Language-Algorithms-Digital-Signal-Processing/dp/0131334069

 

He also has some more recent books advertised on the same page, which look interesting, but I haven’t read them.

 

From: A discussion list for users of Csound [[hidden email]] On Behalf Of Emmett Palaima
Sent: Thursday, February 16, 2017 10:10 PM
To: [hidden email]
Subject: [Csnd] Simple Second Order Lowpass Filter Formula

 

Hi, I'm doing some audio programming in C, and I'm looking for a simple 2nd order lowpass filter design I can implement. Not looking for anything too fancy, just need something like the Tone opcode but with a steeper cutoff. I was looking in the Audio Programming book but it only covers 1st order IIR filters. 

 

Any suggestions?

 

Thanks! 

Csound mailing list [hidden email] https://listserv.heanet.ie/cgi-bin/wa?A0=CSOUND Send bugs reports to https://github.com/csound/csound/issues Discussions of bugs and features can be posted here

 

 

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Re: [Csnd] Simple Second Order Lowpass Filter Formula

epalaima
I will definitely check that one out. $0.95 on Amazon, quite a good deal.

On Fri, Feb 17, 2017 at 1:38 PM, Russell Pinkston <[hidden email]> wrote:

The Csound reson and butterworth filters are all 2nd order, so you can check them out in the sources.

 

But if you’re looking for simple C code, not tied to Csound, I’ve found this book useful: “C Language Algorithms for Digital Signal Processing” by Paul Embree:

 

https://www.amazon.com/Language-Algorithms-Digital-Signal-Processing/dp/0131334069

 

He also has some more recent books advertised on the same page, which look interesting, but I haven’t read them.

 

From: A discussion list for users of Csound [[hidden email]] On Behalf Of Emmett Palaima
Sent: Thursday, February 16, 2017 10:10 PM
To: [hidden email]
Subject: [Csnd] Simple Second Order Lowpass Filter Formula

 

Hi, I'm doing some audio programming in C, and I'm looking for a simple 2nd order lowpass filter design I can implement. Not looking for anything too fancy, just need something like the Tone opcode but with a steeper cutoff. I was looking in the Audio Programming book but it only covers 1st order IIR filters. 

 

Any suggestions?

 

Thanks! 

Csound mailing list [hidden email] https://listserv.heanet.ie/cgi-bin/wa?A0=CSOUND Send bugs reports to https://github.com/csound/csound/issues Discussions of bugs and features can be posted here

 

 

Csound mailing list [hidden email] https://listserv.heanet.ie/cgi-bin/wa?A0=CSOUND Send bugs reports to https://github.com/csound/csound/issues Discussions of bugs and features can be posted here

Csound mailing list [hidden email] https://listserv.heanet.ie/cgi-bin/wa?A0=CSOUND Send bugs reports to https://github.com/csound/csound/issues Discussions of bugs and features can be posted here