lowpass resonant filter sweeping and peak equalization?

Started by tpytel in comp.dsp15 years ago 19 replies

Hi all, it seems like there are some fairly knowledgeable people hanging out here, so I will try my luck after searching high and low on the...

Hi all, it seems like there are some fairly knowledgeable people hanging out here, so I will try my luck after searching high and low on the net. I am working on audio synthesis and am stuck on a couple of things with my 2 pole lowpass resonant IIR filter (it is a standard conjugate pole pair thingy for dealing with real signals of course :) The first thing is peak level equalization. The f...


IIR Filter Funktion with DSP5416

Started by Eugene in comp.dsp15 years ago 2 replies

Hello I can produce with mathlab the coefficients for IIR Filter Bandpassfilter. I can export it as h-file. So I get real64_T NUM[MWSPT][3]...

Hello I can produce with mathlab the coefficients for IIR Filter Bandpassfilter. I can export it as h-file. So I get real64_T NUM[MWSPT][3] and real64_T DEN[MWSPT_NSEC][3] arrays my question is: with the function from DSPLIB iir32(DATA *x,LDATA *h,DATA *r,LDATA **dbuffer ...) should I filter the input. I can't understand what should I take as "h" and "dbuffer". Can I use the coef. from...


IIR Filter Funktion with DSP5416

Started by Eugene in comp.dsp15 years ago 1 reply

Hello, thank you for the answer, for the function iir32(DATA *x, LDATA *h, DATA *r ...) should be the length of 'h' 5*nbiq. If I think...

Hello, thank you for the answer, for the function iir32(DATA *x, LDATA *h, DATA *r ...) should be the length of 'h' 5*nbiq. If I think right, so if the length of Filter is 8, the should be the length of 'h' 4*5=20 If I produce the coef. with Matlab, so I get the number of coefs 24. I can't devide this number with 5. What should I do? Or It isn't the coefs. what I get with matlab...


IIR Filter Funktion with DSP5416

Started by Eugene in comp.dsp15 years ago 1 reply

one more question. 'h' parameter of the function iir32() from DSPLIB have 3 Values for dominator and only 2 values for numenator. so, but I...

one more question. 'h' parameter of the function iir32() from DSPLIB have 3 Values for dominator and only 2 values for numenator. so, but I have the following Array real64_T_T NUM[][3] also I have 3 values for numenator. what is this? thanks


inverse of an FIR filter

Started by Karthik in comp.dsp15 years ago 25 replies

Hi Folks, I read that the inverse of an FIR filter is always an IIR filter. I have no idea how to prove this mathematically. If anybody could...

Hi Folks, I read that the inverse of an FIR filter is always an IIR filter. I have no idea how to prove this mathematically. If anybody could tell me where to start, I'd be more than happy. I'm a DSP newbie, please do excuse me if the question is a little stupid. Thanks, Karthik.


IIR filter design libray

Started by CoCo in comp.dsp15 years ago 43 replies

Hi, I'm currently looking for a PC software library that can be used to dynamically design IIR filters such as Butterworth,...

Hi, I'm currently looking for a PC software library that can be used to dynamically design IIR filters such as Butterworth, Chebychev, Elliptic ... I can't find something that is very well kown. I'm astonished that there is no (or very few) popular libraries to face such a common problem. Does somebody know such a library ? The libray I'm looking for should : - provide routines able ...


Question on IIR filtering

Started by rob.hutchins in comp.dsp15 years ago 7 replies

Hello list, I realize that this may be a very elementary problem, but I'm new to DSP and would very much appreciate your help. If you are...

Hello list, I realize that this may be a very elementary problem, but I'm new to DSP and would very much appreciate your help. If you are given a frequency response and you know that: 1. the part of the curve you're interested in can be modeled using a narrow bandpass IIR filter 2. you want to flatten that part of the curve how would you design the inverse filter? Also, how would...


Question on IIR filtering

Started by rob.hutchins in comp.dsp15 years ago 2 replies

Hello list, I realize that this may be a very elementary problem, but I'm new to DSP and would very much appreciate your help. If you are...

Hello list, I realize that this may be a very elementary problem, but I'm new to DSP and would very much appreciate your help. If you are given a frequency response and you know that: 1. the part of the curve you're interested in can be modeled using a narrow bandpass IIR filter 2. you want to flatten that part of the curve how would you design the inverse filter? Also, how would...


IIR for image processing in Matlab. How???? (Plz help)

Started by Anonymous in comp.dsp15 years ago 2 replies

Hello, would any one out there can help me how to appy IIR to filter an 256x256 image using IIR in Matlab? is there any function for it (I...

Hello, would any one out there can help me how to appy IIR to filter an 256x256 image using IIR in Matlab? is there any function for it (I mean 2 D IIR filter). I have to use a IIR filter to filter a image and it is required that I do it in Matlab. I have done it in C and using difference equation: y(m,n)=a1*x(m,n)+a2*y(m-1,n)+..... and everything is fine. Now I have to do it in ...


[Question] How to get BW or Q from slope(db/oct) for HPF

Started by krish in comp.dsp15 years ago 8 replies

Topic : To design an IIR HPF filter using IPP(Intel Integrated Performance Primitives) library. Current need: to calculate BW or Q from...

Topic : To design an IIR HPF filter using IPP(Intel Integrated Performance Primitives) library. Current need: to calculate BW or Q from slope. The specification of filter is : Cutt-off frequency : in Hz Slope : in dB/oct We are having an IPP library which has IIR filter implementation function. This function has following parameters: pTaps:- Pointer to the array containing the taps. ...


how to calculate quality factor from slope for IIR biQuad filters.

Started by Namrata in comp.dsp15 years ago 6 replies

I am on workin on a live project which is an DSP application. we are using the BIQUAD IIR filter for performing the filtering. for calculating...

I am on workin on a live project which is an DSP application. we are using the BIQUAD IIR filter for performing the filtering. for calculating the filter coefficients we are using the formulas given in http://www.harmony-central.com/Computer/Programming/Audio-EQ-Cookbook.txt for calculating the Alpha value from this formula sheet for the HPF and LPF Quality factor or Bandwidth is required an...


Uppebounding the impulse response of an IIR filter?

Started by Anonymous in comp.dsp15 years ago 2 replies

Hi Everybody, Suppose that you've been provided with a stable IIR filter (which guarantees that its impulse response will become stable). the...

Hi Everybody, Suppose that you've been provided with a stable IIR filter (which guarantees that its impulse response will become stable). the impulse response can be generated by dividing the numerator by denominator and continuing it (long division) as long as desired. There's a point that, based on the IIR filter coefficients, can anybody give a function like C*r^-n in which n is the t...


FIR notch filters using the Windowing method

Started by Greer in comp.dsp15 years ago 41 replies

Hi, I am trying to obtain a FIR notch filter which is very narrow. For example, a 50 Hz notch filter to remove mains noise from a 1250Hz...

Hi, I am trying to obtain a FIR notch filter which is very narrow. For example, a 50 Hz notch filter to remove mains noise from a 1250Hz signal say. Doing this with an IIR filter was easy, I could specify my "notch region" as small as [49 51]Hz. I am now trying to do the same with a FIR filter. I am using Intel Peformance Primative functions to generate the taps. These use the windowing ...


Converting non-Causal IIR to Causal IIR

Started by bdm711 in comp.dsp15 years ago 26 replies

Hello, I am struggling to understand this. I understand that it is possible to have a non-causal IIR Filter (since there are poles and zeros...

Hello, I am struggling to understand this. I understand that it is possible to have a non-causal IIR Filter (since there are poles and zeros with IIR). However, I am given two low-pass filters and two-highpass filters: A(z) = H(z) : Lowpass B(z) = H(-z^-1) : Highpass C(z) = H(z^-1) : Lowpass D(z) = H(-z) : Highpass My thought is in order to have only causal filters you?ll need to add a d...


IIR filter Implementation

Started by Par in comp.dsp14 years ago 42 replies

Hello Guys! I have a brief signal, about 100 values, having unknown frequency components including a single frequency of interest to me. I have...

Hello Guys! I have a brief signal, about 100 values, having unknown frequency components including a single frequency of interest to me. I have designed an IIR filter using MATLAB that will filter out the single frequency. However, since the signal is brief, I face the problem that the filter has a non-zero transient response while handling most of my signal. This causes weird results. W...


IIR filter coefficient quantization newbie

Started by Alxpert in comp.dsp14 years ago 2 replies

I designing a IIR digital filter with the following parameters (Fs = 500k,fc = 1k,fs = 10k,wc = 1db,ws = 40db} using matlab. And I got...

I designing a IIR digital filter with the following parameters (Fs = 500k,fc = 1k,fs = 10k,wc = 1db,ws = 40db} using matlab. And I got the following coefficient using the following .m file. A1 A2 B2 B0 B1 { -1.9725 0.9733 0.0001 0.0001 0.0001 -0.9733 0 0 0.0475 0.0475 } Fs = 500000; fc = 1000; fs = 10000; Rp = 1; ...


IIR with fixed-point numbers?

Started by Elektro in comp.dsp14 years ago 17 replies

What?s the best way to determine the required number of bits necessary in a fixed-point IIR-filter? To avoid overflow during calculations.

What?s the best way to determine the required number of bits necessary in a fixed-point IIR-filter? To avoid overflow during calculations.


ADSP2181 IIR filter help needed please

Started by carlvonclauswitz in comp.dsp14 years ago 1 reply

Hi all, I have designed a 4th order bandpass filter using MatLab FDA tool. The filter contains 2 2nd order stages which is fine and I can...

Hi all, I have designed a 4th order bandpass filter using MatLab FDA tool. The filter contains 2 2nd order stages which is fine and I can view them in Simulink. The filter is a chebyshev type 1 with fp1=300Hz fp2=3kHz. I have the coefficients and scaling factors but have no idea how to code a cascaded (2 sos) filter in ADSP2181 assy language. If anybody could point me in the direction of a go...


Novice to IIR filter

Started by trythisguy in comp.dsp14 years ago 2 replies

I am beginner in DSP. Overall I am hoping to first learn time domain filter before heading to frequency domain. Are all types of IIR filter...

I am beginner in DSP. Overall I am hoping to first learn time domain filter before heading to frequency domain. Are all types of IIR filter considered time domain ? How do i implement a band pass filter. Is there a good explanation on what is meant by priming ? -TryMe This message was sent using the Comp.DSP web interface on www.DSPRelated.com


IIR filter reference designs

Started by Rune Allnor in comp.dsp14 years ago 23 replies

Hi all. I'm struggling to implement my own codes for IIR filter design by analog prototypes. The Butterworth filter works, the Chebyshev type...

Hi all. I'm struggling to implement my own codes for IIR filter design by analog prototypes. The Butterworth filter works, the Chebyshev type 1 doesn't. The books I have available are Proakis & Manolakis' 3rd edition, Oppenheim & Schafer 1975+1999, Leland B Jackson 1989. Most show, relatively crudely, the main steps in filter design. Only P&M show any examples of Cheb 1 filters in suff...