Csound Csound-dev Csound-tekno Search About

[Csnd] Non-linear filters in Csound?

Date2023-05-18 05:46
FromScott Daughtrey
Subject[Csnd] Non-linear filters in Csound?
Inspired by recently playing with an analog virtual synth that apparently uses non-linear filters I was looking at what might function similarly in Csound. Unfortunately only found three obvious choices. Neither nlfilt nor nlfilt2 seemed like great candidates, frankly the parameters seem unintuitive & over my head, I'm used to more standard filter settings like cutoff, Q etc.

And sadly the one I really wanted to try, svn, has not implemented in the rarely updated Csound for Android.

Are there any other options I'm missing here? Some filters are not designated as linear, some are, so I'm not really sure.

Scott

Csound mailing list
Csound@listserv.heanet.ie
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

Date2023-05-18 06:48
FromVictor Lazzarini
SubjectRe: [Csnd] [EXTERNAL] [Csnd] Non-linear filters in Csound?
moogladder, mvclpf3/4 have nonlinearities builtin too.

Prof. Victor Lazzarini
Maynooth University
Ireland

> On 18 May 2023, at 05:47, Scott Daughtrey  wrote:
>
> *Warning*
>
> This email originated from outside of Maynooth University's Mail System. Do not reply, click links or open attachments unless you recognise the sender and know the content is safe.
>
> Inspired by recently playing with an analog virtual synth that apparently uses non-linear filters I was looking at what might function similarly in Csound. Unfortunately only found three obvious choices. Neither nlfilt nor nlfilt2 seemed like great candidates, frankly the parameters seem unintuitive & over my head, I'm used to more standard filter settings like cutoff, Q etc.
>
> And sadly the one I really wanted to try, svn, has not implemented in the rarely updated Csound for Android.
>
> Are there any other options I'm missing here? Some filters are not designated as linear, some are, so I'm not really sure.
>
> Scott
>
> Csound mailing list
> Csound@listserv.heanet.ie
> 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
Csound@listserv.heanet.ie
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

Date2023-05-18 07:50
FromST Music
SubjectRe: [Csnd] [EXTERNAL] [Csnd] Non-linear filters in Csound?
Thanks Victor, I'll have a look at those. 

I noticed in the virtual analog synth, like the svn opcode, there is a drive control in the filter itself. Would using a hyperbolic tangent distortion like the distort1 opcode before the mvclpf4 be likely to have any effect such as increasing the non-linearity of the filter as it does with the svn?

Best, 
Scott

On Thu, May 18, 2023, 1:48 a.m. Victor Lazzarini <Victor.Lazzarini@mu.ie> wrote:
moogladder, mvclpf3/4 have nonlinearities builtin too.

Prof. Victor Lazzarini
Maynooth University
Ireland

> On 18 May 2023, at 05:47, Scott Daughtrey <stunes6556@gmail.com> wrote:
>
> *Warning*
>
> This email originated from outside of Maynooth University's Mail System. Do not reply, click links or open attachments unless you recognise the sender and know the content is safe.
>
> Inspired by recently playing with an analog virtual synth that apparently uses non-linear filters I was looking at what might function similarly in Csound. Unfortunately only found three obvious choices. Neither nlfilt nor nlfilt2 seemed like great candidates, frankly the parameters seem unintuitive & over my head, I'm used to more standard filter settings like cutoff, Q etc.
>
> And sadly the one I really wanted to try, svn, has not implemented in the rarely updated Csound for Android.
>
> Are there any other options I'm missing here? Some filters are not designated as linear, some are, so I'm not really sure.
>
> Scott
>
> Csound mailing list
> Csound@listserv.heanet.ie
> 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
Csound@listserv.heanet.ie
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 Csound@listserv.heanet.ie 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

Date2023-05-18 08:06
FromVictor Lazzarini
SubjectRe: [Csnd] [EXTERNAL] [Csnd] Non-linear filters in Csound?
It would be slightly different as the nonlinearity inside the filter is within the internal feedback delay paths etc, but it should do something.

For the moogladder etc, driving the filter harder (e.g. putting a hotter signal, then
perhaps attenuating the output if needed) would have a similar effect to the svn drive
control. Also the resonance can go beyond 1 
for crunchier high res sounds.

Prof. Victor Lazzarini
Maynooth University
Ireland

On 18 May 2023, at 07:51, ST Music <stunes6556@gmail.com> wrote:


Thanks Victor, I'll have a look at those. 

I noticed in the virtual analog synth, like the svn opcode, there is a drive control in the filter itself. Would using a hyperbolic tangent distortion like the distort1 opcode before the mvclpf4 be likely to have any effect such as increasing the non-linearity of the filter as it does with the svn?

Best, 
Scott

On Thu, May 18, 2023, 1:48 a.m. Victor Lazzarini <Victor.Lazzarini@mu.ie> wrote:
moogladder, mvclpf3/4 have nonlinearities builtin too.

Prof. Victor Lazzarini
Maynooth University
Ireland

> On 18 May 2023, at 05:47, Scott Daughtrey <stunes6556@gmail.com> wrote:
>
> *Warning*
>
> This email originated from outside of Maynooth University's Mail System. Do not reply, click links or open attachments unless you recognise the sender and know the content is safe.
>
> Inspired by recently playing with an analog virtual synth that apparently uses non-linear filters I was looking at what might function similarly in Csound. Unfortunately only found three obvious choices. Neither nlfilt nor nlfilt2 seemed like great candidates, frankly the parameters seem unintuitive & over my head, I'm used to more standard filter settings like cutoff, Q etc.
>
> And sadly the one I really wanted to try, svn, has not implemented in the rarely updated Csound for Android.
>
> Are there any other options I'm missing here? Some filters are not designated as linear, some are, so I'm not really sure.
>
> Scott
>
> Csound mailing list
> Csound@listserv.heanet.ie
> 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
Csound@listserv.heanet.ie
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 Csound@listserv.heanet.ie 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

Date2023-05-18 23:43
FromST Music
SubjectRe: [Csnd] [EXTERNAL] [Csnd] Non-linear filters in Csound?
Thanks again for the tips, Victor. 

On Thu, May 18, 2023, 3:06 a.m. Victor Lazzarini <Victor.Lazzarini@mu.ie> wrote:
It would be slightly different as the nonlinearity inside the filter is within the internal feedback delay paths etc, but it should do something.

For the moogladder etc, driving the filter harder (e.g. putting a hotter signal, then
perhaps attenuating the output if needed) would have a similar effect to the svn drive
control. Also the resonance can go beyond 1 
for crunchier high res sounds.

Prof. Victor Lazzarini
Maynooth University
Ireland

On 18 May 2023, at 07:51, ST Music <stunes6556@gmail.com> wrote:


Thanks Victor, I'll have a look at those. 

I noticed in the virtual analog synth, like the svn opcode, there is a drive control in the filter itself. Would using a hyperbolic tangent distortion like the distort1 opcode before the mvclpf4 be likely to have any effect such as increasing the non-linearity of the filter as it does with the svn?

Best, 
Scott

On Thu, May 18, 2023, 1:48 a.m. Victor Lazzarini <Victor.Lazzarini@mu.ie> wrote:
moogladder, mvclpf3/4 have nonlinearities builtin too.

Prof. Victor Lazzarini
Maynooth University
Ireland

> On 18 May 2023, at 05:47, Scott Daughtrey <stunes6556@gmail.com> wrote:
>
> *Warning*
>
> This email originated from outside of Maynooth University's Mail System. Do not reply, click links or open attachments unless you recognise the sender and know the content is safe.
>
> Inspired by recently playing with an analog virtual synth that apparently uses non-linear filters I was looking at what might function similarly in Csound. Unfortunately only found three obvious choices. Neither nlfilt nor nlfilt2 seemed like great candidates, frankly the parameters seem unintuitive & over my head, I'm used to more standard filter settings like cutoff, Q etc.
>
> And sadly the one I really wanted to try, svn, has not implemented in the rarely updated Csound for Android.
>
> Are there any other options I'm missing here? Some filters are not designated as linear, some are, so I'm not really sure.
>
> Scott
>
> Csound mailing list
> Csound@listserv.heanet.ie
> 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
Csound@listserv.heanet.ie
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 Csound@listserv.heanet.ie 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 Csound@listserv.heanet.ie 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 Csound@listserv.heanet.ie 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