flanger effect, audio interpolation

Started by omal...@gmail.com in comp.dsp11 years ago 1 reply

Hey, I'm implementing a flanger effect as part of a guitar effects processor on an ADSP-21364 development board. A Flanger effect is produced...

Hey, I'm implementing a flanger effect as part of a guitar effects processor on an ADSP-21364 development board. A Flanger effect is produced by adding a single delay to the current input sample, the length of the delay is dictated by a sin wave which i have in aa lookup table. This implements a comb filter. My problem is that on top of the desired output I am also getting a 'police si...


Calculating the gain of a comb-resonator bandpass filter

Started by dazedandconfused in comp.dsp11 years ago 2 replies

Hi, I'm an computer engineering undergrad with what is probably a simple filter question. I need to simulate in Matlab and provide a...

Hi, I'm an computer engineering undergrad with what is probably a simple filter question. I need to simulate in Matlab and provide a mathematical analysis of a bandpass filter by cascading a comb filter with a resonator. The comb has transfer function: Hc(z) = 1 + r^m*z^-m and the resonator: Hr(z) = z^2/(z^2 - 2*r*cos(omega)*z + r^2) = z^2/((z - r*exp(j*omega))(z - r*exp(-j...


my first questions about CIC filter input datatype limit in Matlab

Started by Anonymous in comp.dsp10 years ago 1 reply

hi everyone, when I use FDATools to design a CIC(cascade integrator comb)filter the input datatype must be signed fix point. but after our...

hi everyone, when I use FDATools to design a CIC(cascade integrator comb)filter the input datatype must be signed fix point. but after our sigma delta modulator, the output is in double type. how could I transfer between them in order to use CIC filter in Matlab simulink. forgive me my poor expressions and Thanks a lots zcambrdige


How to add two add two correlated signals, but NOT have comb filtering...

Started by sparafucile17 in comp.dsp9 years ago 12 replies

I have two audio signals that are correlated but one of them is a delayed version of the first signal (let say by 10ms). Now I want to sum...

I have two audio signals that are correlated but one of them is a delayed version of the first signal (let say by 10ms). Now I want to sum them together, but of course, this produces a nasty comb filter. So the first thing that sprung to mind was to allpass the "first" signal to approximate the 10ms delay of the second. This works good because I can tolerate some combing but at higher frequ...


Width of comb filter teeth

Started by sauwen in comp.dsp9 years ago 3 replies

Hi all. Does anyone know how to change the width of a feedback comb filter's teeth? From the general idea on wikipedia, it seems like it is only...

Hi all. Does anyone know how to change the width of a feedback comb filter's teeth? From the general idea on wikipedia, it seems like it is only possible to change the delays and the gain. Thanks


Width of comb filter teeth

Started by sauwen in comp.dsp9 years ago 6 replies

Hi all. Does anyone know how to change the width of a feedback comb filter's teeth? From the general idea on wikipedia, it seems like it is only...

Hi all. Does anyone know how to change the width of a feedback comb filter's teeth? From the general idea on wikipedia, it seems like it is only possible to change the delays and the gain. Thanks


QUESTION FOR Rick Lyons Re: tips and tricks book

Started by Dirk Bell in comp.dsp8 years ago 12 replies

Hi Rick, I was reading a chapter in the DSP tips and tricks book on using comb filtering after two-level saturated sampling for FSK...

Hi Rick, I was reading a chapter in the DSP tips and tricks book on using comb filtering after two-level saturated sampling for FSK demod preprocessing. The text said a comb filter equivalent could be made with a direct path and a delayed path input into an XOR gate because the inputs were binary. However, for the binary inputs, the outputs of an XOR are normally 2 level, while the output...


Notch comb filter coefficients

Started by ombz in comp.dsp7 years ago 4 replies

Hi all. I've found in MATLAB help that a notching comb filter has following tranfser function: H(z) = b*(1+z^(-N))/(1+a*z^(-N)) where N is...

Hi all. I've found in MATLAB help that a notching comb filter has following tranfser function: H(z) = b*(1+z^(-N))/(1+a*z^(-N)) where N is the number of notches. How to determine coefficients a and b with respect to real-world parameters such as sampling frequency, notch frequency and notch bandwidth/resp. attenuation? I don't have the filter toolbox and therefore not the 'iircomb' functio...


generalized comb filters: help with terminology...

Started by robert bristow-johnson in comp.dsp6 years ago 10 replies

okay, we know about comb filters. https://ccrma.stanford.edu/~jos/pasp/Comb_Filters.html the simplest are feedforward comb...

okay, we know about comb filters. https://ccrma.stanford.edu/~jos/pasp/Comb_Filters.html the simplest are feedforward comb filters: y[n] = b_0*x[n] + b_M*x[n-M] H(z) = b_0 + b_M*z^-M then there are feedback comb filters: y[n] = b_0*x[n] - a_M*y[n-M] H(z) = b_0 / (1 + a_M*z^-M) now, isn't it still a "comb filter" when you combine the t...


CIC equations mystery

Started by kaz in comp.dsp3 years ago 7 replies

Hi All 1) According to M.Donadio article "Cascaded Integrator-Comb Filter Introduction" Hf = (sin(pi*f*M)./sin(pi*f/R)).^N; where Hf =...

Hi All 1) According to M.Donadio article "Cascaded Integrator-Comb Filter Introduction" Hf = (sin(pi*f*M)./sin(pi*f/R)).^N; where Hf = amplitude response at frequency f M = number of comb delay stages N = number of cascaded comb/integrator pairs R = rate change(up or down) 2) According to Rick Lyon's article "Understanding cascaded Integrator-comb" Hf = (sin(pi*f*D)/sin(pi*f)).^M ...