Frequency response is the quantitative measure of the output spectrum of a system or device in response to a stimulus, and is used to characterize the dynamics of the system.

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Is the following system LTI (finite speed of signal propagation)?

I wonder if the following acoustic system is i) considered to be linear time-invariant, and ii) if it is fully described by it's frequency response? A speaker produces waves at the input location of ...
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83 views

Frequency response equivalent to characterise transient response (to sinusoidal inputs)?

I am interested in characterising the time-dependent response of a system to a sinusoidal input. The steady state response of the system is also sinusoidal, however I wonder if there is a standard ...
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40 views

Impulse Response from Frequency Response at Specific Values

I'm at a loss trying to answer the following question: The frequency response $H(j\omega)$ of a length 4 FIR filter with real impulse response has the following specific values: $H(j\cdot0) = 2$, ...
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2answers
152 views

Convolution in the frequency domain

We often hear that "convolution in time is the same as multiplication in frequency", and vice versa, that "convolution in frequency is the same as multiplication in time". So in a typical windowing ...
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40 views

Find Difference Equation From Frequency Response

Given the frequency response $H (jω) = csc(ω)$ how would I go about finding the difference equation? I know I can find $h[n]$ from here but after that I feel like I'm missing something.
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30 views

Frequency Response Notation

Why do people sometimes write $H(e^{j\omega})$, some others use $H(\omega)$ and even others use $H(f)$ with $\omega=2\pi f$ to describe the frequency response of a filter or a spectrum? Is there any ...
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1answer
135 views

Normalized frequency in matlab

I have a progam in matlab that generates a linear and quadratic chirp, and now I want to study the frequency components in wvtool. However, I am not able to decode the frquency domain scale "the ...
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2answers
168 views

Convert frequency response to impulse response

I am running an acoustic simulation. I put in a frequency and get out a complex number; the frequency response for that frequency. I wish to generate a 1024-sample impulse response (supposing my ...
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167 views

The impulse response, $h(t)$, of a system

I have this differential equation $$ y''(t) + y'(t) + y(t) = x(t) - 3x'(t) $$ I found the system response of the system: $$ H(f) = \frac{1 - 6\pi fj}{(2\pi fj)^2 +2\pi fj+1} ...
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128 views

Solving linear system and find impulse response

I have this linear system that is defined by the differential equation $$ y''(t) + 4y'(t) + 5y(t) = 2x(t) + 3x'(t) $$ with x(t) the input and y(t) the output. I'm asked to find two ...
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41 views

Obtaining the magnitude of the frequency response by plugging $e^{jω}$ into the z-domain transform function?

I am reading a text on discrete signal processing, which states that the frequency response of a signal can be obtained by plugging the value $e^{jω}$ into the z-domain transfer function $H(z)$. In ...
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268 views

1/3 octave spectra from fft

I have got a signal in frequency domain. This is a frequency response function from software, so I can do nothing about it and have to leave it in frequency domain. I want to transfer the data to 1/3 ...
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94 views

Attempting to use the trapezoidal rule to form a difference equation representing a circuit

I have a differential equation that has been proven to be correct. The transfer function obtained by Laplace domain analysis and Matlab freqs match up and all is well. The problem is somewhere in ...
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69 views

Fourier Transform & Convolution to get response - confused

in the past couple of years I've always been using Laplace transform for system responses, but today tried to do it with Fourier transform and failed. What am I doing wrong? If we have a signal $x(t) ...
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1answer
103 views

WIDELY UNKNOWN?? Wireless Channel Transfer Function or freq response - frequency vs attenuation

We know that the signal attenuates out with distance and according to the channel transfer function or frequency response, the signal frequency components attenuate to different values based on ...
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1answer
37 views

Frequency response using fourier transform [duplicate]

i need to find the frequency response of the following equations: $$h(t) = \delta(t) +e^{-2(t-1)} u(t-1)$$ $$x(t) = \cos\left(\frac{pi}{4}t\right)+2\cos\left(\frac{pi}{2}t\right)$$ find $y(t)$ ...
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84 views

Frequency response using fourier

i need to find the frequency response of the following equations: $$h(t) = e^{-3t} u(t)$$ $$x(t) = 1+\cos\left(\frac{4\pi}{3}t\right)$$ find $y(t)$ However i am quite confused on how to do this, ...
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139 views

Hints and helps to implement an accurate wavelet packet transfrom

I want to implement a Time-Freqency analysis by wavelet packets. I don't know what level and sampling rate should I use. I've tried different value for level(3,4,5,6,). but I couldn't get an accurate ...
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2answers
479 views

Digital implementation of first order analog filter using bilinear transformation

I'm trying to create a digital filter from a first order analog filter with transfer function $$H(s)=\frac{1}{1+\tau s}$$ with time constant $\tau=.1\text{s}$, and sampling rate $f_s=1000\text{Hz}$. ...
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2answers
536 views

For a LTI system, why does the Fourier transform of the impulse response give the frequency response?

I know that for a given system, the Fourier transform of its impulse response gives its frequency response. I want to find where this property comes from, but haven't been able to find if it's a ...
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1answer
86 views

Guess the frequency response of a filter with little information

I have a processing unit that does a nice EQ filtering on soundfiles. The only thing I can do is : I give the original .wav file, and the processing unit gives me back the filtered .wav. I have no ...
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3answers
309 views

Draw a frequency response graph from a simple equation

How is it possible to draw an audio frequency response graph (x-axis : freq from 20 to 20 000hz, y-axis : dB) from a simple equation like y[n] = x[n] - x[n-486] ...
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61 views

Calculating complex frequency response and transforming a sinusoid question

I need help with a question from signal processing class. Question as follows: Question is in two parts Part 1: The ideal delay system is defined by $y[n] = x[n-n_{d}]$. First, derive the systems ...
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1answer
117 views

How to append two bandlimited signals and make the result bandlimited without modifying the first signal

I need to append (not add) a bandlimited signal F(b) to a bandlimited signal F(a) and keep the result bandlimited without modifying the part that corresponds to F(a). Both are bandlimited to the same ...
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138 views

inverse FFT when only a few time points are needed

I am developing C++ code to do some modeling that will take as input a parametric model of the complex frequency response (amplitude, phase) and produce as output an impulse response, e.g. using the ...
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79 views

IIR: get magnitude and phase from coefficients

i'm trying to plot 1)the magnitude and 2)the phase response of an IIR eq with only its coefficients. i've found somewhere that one can find the magnitude response starting with the transfer function ...
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37 views

Stability varying with order

I have been doing some research into modelling acoustic spaces, and (with help from this site) I've managed to take the frequency response of fibrous layer model, convert it to a reflection response ...
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176 views

Least Square Digital IIR Filter Design (with arbitrary responses)

i'm studying the IIr filter design that is described in the book : Algorithms for the constrained design of digital filters with arbitrary phase and magnitude responses you can get the code at page ...
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2answers
157 views

Berchin's FDLS arbitrary filter design algorithm

i'm trying to use Berchin's FDLS methods (for those that don't know what it is, it's a way to design arbitrary magnitude and phase of an IIR Eq) I tried different things but neither gave me what i ...
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1answer
292 views

What is the meaning of a Nyquist diagram in a vibration signal

I need to analyze some vibration data from accelerometers (g-Hz) but I don't quite understand the meaning of each component that the registered signal contains. Basically it is Magnitude and Phase. ...
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195 views

How can I draw Bode plot for experimental time series?

I have time-amplitude data collected from an acceleration sensor. I need to plot the Bode diagram of the data. How can I do it? is it possible in MATLAB or Scipy? I am new to these programming ...
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How poles are related to frequency response

I have recently fallen into fallacy, considering pole s=1 as there is infinite response at frequency 1. Yet, response was only 1. Now, can you derive the frequency response, given the poles? ...
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what is the frequency response?

I try to work out the simplest system, whose response is $H(z) = 1 + cz + c^2z^2 + c^3z^3 + \cdots = 1 / (1-cz)$ Now, Z-transform done quick (Fourier connection) and 4.5 Transfer Function, Poles and ...
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120 views

Frequency response of system with feedback and feedforward co-efficients?

For seismological application, I am playing with an elliptical filter, and once I have both sets of feedback and feedforward co-efficients, how do I make it so that I can plot the frequency response ...
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1answer
134 views

Gain function calculation (frequency response)

Define moving average process $y_t := 0.5 x_t + 0.5 x_{t-1}$ where $x_t := e^{i2 \pi t}$. Its frequency response is then: $$H(f) = 0.5 + 0.5 e^{-i2\pi f}$$ Recall that the frequency response in ...
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63 views

Multiple filters or not?

I'm processing audio signal sampled at 44.1 kHz. After some other processing, I need to filter the signal between ~5-50 Hz. Achieving this for a signal with such a high sampling frequency appears to ...
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2answers
605 views

Finding the frequency response of a filter defined as a Z-domain transfer function

I am software engineer studying DSP on my own. I came across this question in a graduate textbook and am not sure how to proceed. ...
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0answers
102 views

Digital control: Exercise solution

Can you help me (show me how) to solve the following exercise? For the process with transfer function $G(s)=e^{-2s}/(s+1)$ design a digital controller with sampling time $T_{s} = 1$ that meets the ...
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1answer
200 views

Impulse Response Question

For the differential equation $$\frac{d^2y(t)}{dt^2}+\frac{3dy(t)}{dt} + 2y = x(t),$$ I was able to find the frequency response as $$H(j\omega)= \frac{1}{-\omega^2+3j\omega+2}.$$ However, I am not ...
3
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1answer
206 views

Frequency response of Low pass filter and High pass filter

The transfer function of a Low pass filter is H(w). From this I want to develop a high Pass filter. I read in DSP by Proakis, Sec 4.5, that the high pass filter can be obtained by translating H(w) by ...
4
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1answer
210 views

Constant Magnitude Chirp across audio band (Parseval's Theorem?)

I want to excite a loudspeaker with a constant magnitude chirp that sweeps across all frequencies in the audio band. I downloaded a test file from this website to start with. I plot the log magnitude ...
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153 views

Find the frequency response if i have the magnitude response?

if i have the transfer function of magnitude response is there a method that i could calculate the frequency response? For example the transfer function of the magnitude response is: $ 3db \pm ...
4
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1answer
282 views

Approximating the frequency response of a median filter

A median filter is a non-linear and lossy process, so it doesn't have a closed form frequency response as would a FIR filter (say a box filter of the same length) in an LTI system. But how closely ...
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3answers
582 views

Why is the gain of my IIR filter positive?

Sorry, two questions in one day! I'm struggling to understand what I'm doing wrong in this very simple filter design. I want to design a simple, single pole low pass filter and implement it as an IIR ...
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1answer
72 views

narrow band frequency response creation and general FR question

i need some guidance with understanding frequency response characteristics. i have the a signal A with is played on speakers and recorded via microphone which is signal B. then i apply a window ...
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376 views

Obtaining the Impulse response from the frequency of a discrete system

I have the following discrete system's transfer function (Z domain): $$h[z] = {z \over z - \frac{1}{2} }$$ I need to obtain the following: The frequency response. The impulse response. The fourier ...
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Impulse Response / Frequency response Question [closed]

I have a major question. Please take a look. I have this differential equation (DE): $$ \frac{d^2y(t)}{dt} +\frac{dy(t)}{dt} +4y(t)= \frac{dx(t)}{dt} +2x(t) $$ And I have to find impulse response ...
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2answers
168 views

Find the frequency response of a system

I'm trying to find the frequency response $$H(\omega) = Y(\omega)/X(\omega)$$ for this system- the signal equations are given: $$y[n] = v[n - M] - g * v[n]$$ $$v[n] = x[n] + g * v[n - M]$$ I've tried ...
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136 views

Evaluating loudspeakers

If you don't have a lot of money to spend but you want to estimate the frequency response of different loudspeaker setups what is the best way to do it? I bought a very nice microphone and built a ...
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1answer
259 views

Calculating the system output using frequency response

Given an input signal $$x(n)=\cos(6\pi n +\frac{\pi}{6})$$ and system $$y(n)=0.5x(n)-0.1x(n-1)$$. In this case, the coefficients of the difference equation are $a_0=1$, $b_0=0.5$, and $b_1=$. The ...