[Csnd] filter design

[Csnd] filter design

Date	2013-02-02 21:48
From	Adam Puckett
Subject	[Csnd] filter design
	Hi, Is subtractive synthesis called what it is because sine waves are subtracted from a signal? e.g., signal - (sin(2 * pi * t) * amp)? I've thought about this for a while, because I've been using Python's wave module to create computer music "the hard way" by "drawing" (using numbers and functions instead of ugens) different waveforms (sort of like a combo of GENs 7 and 2). The algorithms in Csound seem like they're optimized, but then again I haven't looked at them closely enough to be sure.

Date	2013-02-02 21:57
From	Justin Smith
Subject	Re: [Csnd] filter design
	signal - (sin(2 * pi * t) * amp) would add a -1 hz component, if t is time in seconds negative frequencies are exactly the same as positive to the human ear, though they do cancel out with an identical positive frequency when the two are added, if they have identical phase subtractive synthesis is done via filtration of a rich input sound filtration and rich are accomplished in a number of ways, but you could start with a resonant lowpass filter and either buzz or noise On Sat, Feb 2, 2013 at 1:48 PM, Adam Puckett <adotsdothmusic@gmail.com> wrote: Hi, Is subtractive synthesis called what it is because sine waves are subtracted from a signal? e.g., signal - (sin(2 * pi * t) * amp)? I've thought about this for a while, because I've been using Python's wave module to create computer music "the hard way" by "drawing" (using numbers and functions instead of ugens) different waveforms (sort of like a combo of GENs 7 and 2). The algorithms in Csound seem like they're optimized, but then again I haven't looked at them closely enough to be sure. Send bugs reports to the Sourceforge bug tracker https://sourceforge.net/tracker/?group_id=81968&atid=564599 Discussions of bugs and features can be posted here To unsubscribe, send email sympa@lists.bath.ac.uk with body "unsubscribe csound"

Date	2013-02-02 22:10
From	Adam Puckett
Subject	Re: [Csnd] filter design
	But how would I design the filter in the first place? On 2/2/13, Justin Smith wrote: > signal - (sin(2 * pi * t) * amp) > > would add a -1 hz component, if t is time in seconds > > negative frequencies are exactly the same as positive to the human ear, > though they do cancel out with an identical positive frequency when the two > are added, if they have identical phase > > subtractive synthesis is done via filtration of a rich input sound > > filtration and rich are accomplished in a number of ways, but you could > start with a resonant lowpass filter and either buzz or noise > > > On Sat, Feb 2, 2013 at 1:48 PM, Adam Puckett > wrote: > >> Hi, >> >> Is subtractive synthesis called what it is because sine waves are >> subtracted from a signal? e.g., signal - (sin(2 * pi * t) * amp)? I've >> thought about this for a while, because I've been using Python's wave >> module to create computer music "the hard way" by "drawing" (using >> numbers and functions instead of ugens) different waveforms (sort of >> like a combo of GENs 7 and 2). The algorithms in Csound seem like >> they're optimized, but then again I haven't looked at them closely >> enough to be sure. >> >> >> Send bugs reports to the Sourceforge bug tracker >> https://sourceforge.net/tracker/?group_id=81968&atid=564599 >> Discussions of bugs and features can be posted here >> To unsubscribe, send email sympa@lists.bath.ac.uk with body "unsubscribe >> csound" >> >> > > Send bugs reports to the Sourceforge bug tracker > https://sourceforge.net/tracker/?group_id=81968&atid=564599 > Discussions of bugs and features can be posted here > To unsubscribe, send email sympa@lists.bath.ac.uk with body "unsubscribe > csound" > >

Date	2013-02-02 22:16
From	Justin Smith
Subject	Re: [Csnd] filter design
	output[n] = (signal[n-1]/2) + (signal[n]/2) (where signal and output are arrays and signal[n] is the signal value at time n in samples) is a simple fir low pass, and demonstrates some of the first basic principles of filtering http://en.wikipedia.org/wiki/Filter_design people spend years learning the answer to that question unless you really enjoy higher level math, you may want to just use one of the existing standards On Sat, Feb 2, 2013 at 2:10 PM, Adam Puckett <adotsdothmusic@gmail.com> wrote: But how would I design the filter in the first place? On 2/2/13, Justin Smith <noisesmith@gmail.com> wrote: > signal - (sin(2 * pi * t) * amp) > > would add a -1 hz component, if t is time in seconds > > negative frequencies are exactly the same as positive to the human ear, > though they do cancel out with an identical positive frequency when the two > are added, if they have identical phase > > subtractive synthesis is done via filtration of a rich input sound > > filtration and rich are accomplished in a number of ways, but you could > start with a resonant lowpass filter and either buzz or noise > > > On Sat, Feb 2, 2013 at 1:48 PM, Adam Puckett > <adotsdothmusic@gmail.com>wrote: > >> Hi, >> >> Is subtractive synthesis called what it is because sine waves are >> subtracted from a signal? e.g., signal - (sin(2 * pi * t) * amp)? I've >> thought about this for a while, because I've been using Python's wave >> module to create computer music "the hard way" by "drawing" (using >> numbers and functions instead of ugens) different waveforms (sort of >> like a combo of GENs 7 and 2). The algorithms in Csound seem like >> they're optimized, but then again I haven't looked at them closely >> enough to be sure. >> >> >> Send bugs reports to the Sourceforge bug tracker >> https://sourceforge.net/tracker/?group_id=81968&atid=564599 >> Discussions of bugs and features can be posted here >> To unsubscribe, send email sympa@lists.bath.ac.uk with body "unsubscribe >> csound" >> >> > > Send bugs reports to the Sourceforge bug tracker > https://sourceforge.net/tracker/?group_id=81968&atid=564599 > Discussions of bugs and features can be posted here > To unsubscribe, send email sympa@lists.bath.ac.uk with body "unsubscribe > csound" > > Send bugs reports to the Sourceforge bug tracker https://sourceforge.net/tracker/?group_id=81968&atid=564599 Discussions of bugs and features can be posted here To unsubscribe, send email sympa@lists.bath.ac.uk with body "unsubscribe csound"

Date	2013-02-02 22:21
From	Adam Puckett
Subject	Re: [Csnd] filter design
	So with that array assignment how would I specify a cutoff frequency? On 2/2/13, Justin Smith wrote: > output[n] = (signal[n-1]/2) + (signal[n]/2) (where signal and output are > arrays and signal[n] is the signal value at time n in samples) is a simple > fir low pass, and demonstrates some of the first basic principles of > filtering > > http://en.wikipedia.org/wiki/Filter_design > > people spend years learning the answer to that question > > unless you really enjoy higher level math, you may want to just use one of > the existing standards > > > > On Sat, Feb 2, 2013 at 2:10 PM, Adam Puckett > wrote: > >> But how would I design the filter in the first place? >> >> On 2/2/13, Justin Smith wrote: >> > signal - (sin(2 * pi * t) * amp) >> > >> > would add a -1 hz component, if t is time in seconds >> > >> > negative frequencies are exactly the same as positive to the human ear, >> > though they do cancel out with an identical positive frequency when the >> two >> > are added, if they have identical phase >> > >> > subtractive synthesis is done via filtration of a rich input sound >> > >> > filtration and rich are accomplished in a number of ways, but you could >> > start with a resonant lowpass filter and either buzz or noise >> > >> > >> > On Sat, Feb 2, 2013 at 1:48 PM, Adam Puckett >> > wrote: >> > >> >> Hi, >> >> >> >> Is subtractive synthesis called what it is because sine waves are >> >> subtracted from a signal? e.g., signal - (sin(2 * pi * t) * amp)? I've >> >> thought about this for a while, because I've been using Python's wave >> >> module to create computer music "the hard way" by "drawing" (using >> >> numbers and functions instead of ugens) different waveforms (sort of >> >> like a combo of GENs 7 and 2). The algorithms in Csound seem like >> >> they're optimized, but then again I haven't looked at them closely >> >> enough to be sure. >> >> >> >> >> >> Send bugs reports to the Sourceforge bug tracker >> >> >> >> https://sourceforge.net/tracker/?group_id=81968&atid=564599 >> >> Discussions of bugs and features can be posted here >> >> To unsubscribe, send email sympa@lists.bath.ac.uk with body >> "unsubscribe >> >> csound" >> >> >> >> >> > >> > Send bugs reports to the Sourceforge bug tracker >> > https://sourceforge.net/tracker/?group_id=81968&atid=564599 >> > Discussions of bugs and features can be posted here >> > To unsubscribe, send email sympa@lists.bath.ac.uk with body >> > "unsubscribe >> > csound" >> > >> > >> >> >> Send bugs reports to the Sourceforge bug tracker >> https://sourceforge.net/tracker/?group_id=81968&atid=564599 >> Discussions of bugs and features can be posted here >> To unsubscribe, send email sympa@lists.bath.ac.uk with body "unsubscribe >> csound" >> >> > > Send bugs reports to the Sourceforge bug tracker > https://sourceforge.net/tracker/?group_id=81968&atid=564599 > Discussions of bugs and features can be posted here > To unsubscribe, send email sympa@lists.bath.ac.uk with body "unsubscribe > csound" > >

Date	2013-02-02 22:25
From	Justin Smith
Subject	Re: [Csnd] filter design
	http://en.wikipedia.org/wiki/Finite_impulse_response#Filter_design I am incapable of a simpler explanation than the one presented there filter design is much more complex than additive synthesis etc. On Sat, Feb 2, 2013 at 2:21 PM, Adam Puckett <adotsdothmusic@gmail.com> wrote: So with that array assignment how would I specify a cutoff frequency? On 2/2/13, Justin Smith <noisesmith@gmail.com> wrote: > output[n] = (signal[n-1]/2) + (signal[n]/2) (where signal and output are > arrays and signal[n] is the signal value at time n in samples) is a simple > fir low pass, and demonstrates some of the first basic principles of > filtering > > http://en.wikipedia.org/wiki/Filter_design > > people spend years learning the answer to that question > > unless you really enjoy higher level math, you may want to just use one of > the existing standards > > > > On Sat, Feb 2, 2013 at 2:10 PM, Adam Puckett > <adotsdothmusic@gmail.com>wrote: > >> But how would I design the filter in the first place? >> >> On 2/2/13, Justin Smith <noisesmith@gmail.com> wrote: >> > signal - (sin(2 * pi * t) * amp) >> > >> > would add a -1 hz component, if t is time in seconds >> > >> > negative frequencies are exactly the same as positive to the human ear, >> > though they do cancel out with an identical positive frequency when the >> two >> > are added, if they have identical phase >> > >> > subtractive synthesis is done via filtration of a rich input sound >> > >> > filtration and rich are accomplished in a number of ways, but you could >> > start with a resonant lowpass filter and either buzz or noise >> > >> > >> > On Sat, Feb 2, 2013 at 1:48 PM, Adam Puckett >> > <adotsdothmusic@gmail.com>wrote: >> > >> >> Hi, >> >> >> >> Is subtractive synthesis called what it is because sine waves are >> >> subtracted from a signal? e.g., signal - (sin(2 * pi * t) * amp)? I've >> >> thought about this for a while, because I've been using Python's wave >> >> module to create computer music "the hard way" by "drawing" (using >> >> numbers and functions instead of ugens) different waveforms (sort of >> >> like a combo of GENs 7 and 2). The algorithms in Csound seem like >> >> they're optimized, but then again I haven't looked at them closely >> >> enough to be sure. >> >> >> >> >> >> Send bugs reports to the Sourceforge bug tracker >> >> >> >> https://sourceforge.net/tracker/?group_id=81968&atid=564599 >> >> Discussions of bugs and features can be posted here >> >> To unsubscribe, send email sympa@lists.bath.ac.uk with body >> "unsubscribe >> >> csound" >> >> >> >> >> > >> > Send bugs reports to the Sourceforge bug tracker >> > https://sourceforge.net/tracker/?group_id=81968&atid=564599 >> > Discussions of bugs and features can be posted here >> > To unsubscribe, send email sympa@lists.bath.ac.uk with body >> > "unsubscribe >> > csound" >> > >> > >> >> >> Send bugs reports to the Sourceforge bug tracker >> https://sourceforge.net/tracker/?group_id=81968&atid=564599 >> Discussions of bugs and features can be posted here >> To unsubscribe, send email sympa@lists.bath.ac.uk with body "unsubscribe >> csound" >> >> > > Send bugs reports to the Sourceforge bug tracker > https://sourceforge.net/tracker/?group_id=81968&atid=564599 > Discussions of bugs and features can be posted here > To unsubscribe, send email sympa@lists.bath.ac.uk with body "unsubscribe > csound" > > Send bugs reports to the Sourceforge bug tracker https://sourceforge.net/tracker/?group_id=81968&atid=564599 Discussions of bugs and features can be posted here To unsubscribe, send email sympa@lists.bath.ac.uk with body "unsubscribe csound"

Date	2013-02-02 22:47
From	peiman khosravi
Subject	Re: [Csnd] filter design
	Talking about filter. Is there a Csound article that introduces different filter in Csound? Thanks Peiman On 2 February 2013 22:25, Justin Smith <noisesmith@gmail.com> wrote: http://en.wikipedia.org/wiki/Finite_impulse_response#Filter_design I am incapable of a simpler explanation than the one presented there filter design is much more complex than additive synthesis etc. On Sat, Feb 2, 2013 at 2:21 PM, Adam Puckett <adotsdothmusic@gmail.com> wrote: So with that array assignment how would I specify a cutoff frequency? On 2/2/13, Justin Smith <noisesmith@gmail.com> wrote: > output[n] = (signal[n-1]/2) + (signal[n]/2) (where signal and output are > arrays and signal[n] is the signal value at time n in samples) is a simple > fir low pass, and demonstrates some of the first basic principles of > filtering > > http://en.wikipedia.org/wiki/Filter_design > > people spend years learning the answer to that question > > unless you really enjoy higher level math, you may want to just use one of > the existing standards > > > > On Sat, Feb 2, 2013 at 2:10 PM, Adam Puckett > <adotsdothmusic@gmail.com>wrote: > >> But how would I design the filter in the first place? >> >> On 2/2/13, Justin Smith <noisesmith@gmail.com> wrote: >> > signal - (sin(2 * pi * t) * amp) >> > >> > would add a -1 hz component, if t is time in seconds >> > >> > negative frequencies are exactly the same as positive to the human ear, >> > though they do cancel out with an identical positive frequency when the >> two >> > are added, if they have identical phase >> > >> > subtractive synthesis is done via filtration of a rich input sound >> > >> > filtration and rich are accomplished in a number of ways, but you could >> > start with a resonant lowpass filter and either buzz or noise >> > >> > >> > On Sat, Feb 2, 2013 at 1:48 PM, Adam Puckett >> > <adotsdothmusic@gmail.com>wrote: >> > >> >> Hi, >> >> >> >> Is subtractive synthesis called what it is because sine waves are >> >> subtracted from a signal? e.g., signal - (sin(2 * pi * t) * amp)? I've >> >> thought about this for a while, because I've been using Python's wave >> >> module to create computer music "the hard way" by "drawing" (using >> >> numbers and functions instead of ugens) different waveforms (sort of >> >> like a combo of GENs 7 and 2). The algorithms in Csound seem like >> >> they're optimized, but then again I haven't looked at them closely >> >> enough to be sure. >> >> >> >> >> >> Send bugs reports to the Sourceforge bug tracker >> >> >> >> https://sourceforge.net/tracker/?group_id=81968&atid=564599 >> >> Discussions of bugs and features can be posted here >> >> To unsubscribe, send email sympa@lists.bath.ac.uk with body >> "unsubscribe >> >> csound" >> >> >> >> >> > >> > Send bugs reports to the Sourceforge bug tracker >> > https://sourceforge.net/tracker/?group_id=81968&atid=564599 >> > Discussions of bugs and features can be posted here >> > To unsubscribe, send email sympa@lists.bath.ac.uk with body >> > "unsubscribe >> > csound" >> > >> > >> >> >> Send bugs reports to the Sourceforge bug tracker >> https://sourceforge.net/tracker/?group_id=81968&atid=564599 >> Discussions of bugs and features can be posted here >> To unsubscribe, send email sympa@lists.bath.ac.uk with body "unsubscribe >> csound" >> >> > > Send bugs reports to the Sourceforge bug tracker > https://sourceforge.net/tracker/?group_id=81968&atid=564599 > Discussions of bugs and features can be posted here > To unsubscribe, send email sympa@lists.bath.ac.uk with body "unsubscribe > csound" > > Send bugs reports to the Sourceforge bug tracker https://sourceforge.net/tracker/?group_id=81968&atid=564599 Discussions of bugs and features can be posted here To unsubscribe, send email sympa@lists.bath.ac.uk with body "unsubscribe csound"