Re: [music-dsp] IIR Coefficient Switching Glitches

Chris: Figure out the constant-q stuff and you can fit resonance to most things. (equal feedback amount for a setting, in all frequencies). I have not done this yet. Maybe someone else here knows more about constant-Q? Peace Be With You. -- Ove Karlsen, www.ovekarlsen.com -- dupswapdrop -- the

Re: [music-dsp] IIR Coefficient Switching Glitches

On Sun, Nov 3, 2013 at 2:26 PM, robert bristow-johnson wrote: > On 11/3/13 10:21 AM, Chris Townsend wrote: >> >> Thanks guys. I was also thinking a Moog style filter with first order >> sections inside a feedback loop might work me, since it performs well >> under high rates of coefficient change

Re: [music-dsp] IIR Coefficient Switching Glitches

On 11/3/13 10:21 AM, Chris Townsend wrote: Thanks guys. I was also thinking a Moog style filter with first order sections inside a feedback loop might work me, since it performs well under high rates of coefficient changes. It seems like you could make a fully general 2nd order filter by using

Re: [music-dsp] IIR Coefficient Switching Glitches

to a bypass set of coefficients first, then ramp to the second filter type. Rob -Original Message- From: Ross Bencina Sent: Sunday, November 03, 2013 8:17 AM To: A discussion list for music-related DSP Subject: Re: [music-dsp] IIR Coefficient Switching Glitches On 3/11/2013 3:22 PM, La

Re: [music-dsp] IIR Coefficient Switching Glitches

Apparently, modulated second-order recursive filters can have stability problems even if the coefficients at any given time satisfy the triangle law for stability. Jean Laroche's article on "Using resonant filters for the synthesis of time-varying sinusoids" discusses this: http://scholar.googl

Re: [music-dsp] IIR Coefficient Switching Glitches

Ove Karlsen wrote: A linear smoother might fix some issues, on filters that are sensitive to fast changes. Also for filters that seems to work fine with EQs, highpasses, my own Minimal-phase IIR Gaussians work fine (Beneficient Open-Source Licence). Variable order up to 9th, and variable cutoff,

Re: [music-dsp] IIR Coefficient Switching Glitches

Thanks guys. I was also thinking a Moog style filter with first order sections inside a feedback loop might work me, since it performs well under high rates of coefficient changes. It seems like you could make a fully general 2nd order filter by using two first order shelf filters. In addition t

Re: [music-dsp] IIR Coefficient Switching Glitches

A linear smoother might fix some issues, on filters that are sensitive to fast changes. Also for filters that seems to work fine with EQs, highpasses, my own Minimal-phase IIR Gaussians work fine (Beneficient Open-Source Licence). Variable order up to 9th, and variable cutoff, with 5 onepoles

Re: [music-dsp] IIR Coefficient Switching Glitches

On 3/11/2013 3:22 PM, Laurent de Soras wrote: Chris Townsend wrote: Any ideas? Recommendations? Probably this: Consider ramping interpolated coefficients at audio rate to smooth out parameter changes. I'm pretty sure that Andy's

Re: [music-dsp] IIR Coefficient Switching Glitches

Sorry for the double post. For some reason I'm not getting the original messages sent back to me by the list-server. But now I see them shown in the message archives, so apparently both made it. Anyhow, my question still stands. Thanks, Chris On Sat, Nov 2, 2013 at 8:53 PM, Chris Townsend wrot

Re: [music-dsp] IIR Coefficient Switching Glitches

Chris Townsend wrote: Any ideas? Recommendations? Probably this: -- Laurent de Soras | Ohm Force DSP developer & Software designer | Digital Audio Software http://ldesoras.free.fr | http://

[music-dsp] IIR Coefficient Switching Glitches

I'm working on an algorithm with some user controlled "presets" that adjust various IIR filters under the hood. This generally works fine, but I get pops and glitches when switching between certain settings. The filters that are causing trouble are typically second order hipass filters with a sub