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Questions tagged [signal-synthesis]

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0
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1answer
46 views

Difference between two sine generators

I have two sine oscillators and I get these two different spectrum analysis (let's disregard the slight frequency difference). Is there any deductions that can be made about the "quality", or sine ...
2
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0answers
27 views

Is it possible to approximate certain skewness and kurtosis values using an IFFT?

I have time domain data for a signal that behaves randomly but has non-random (non-Gaussian?) skewness and kurtosis values of ~0.9 and ~7.4, respectively. The FFT of the signal shows that it's not ...
0
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0answers
14 views

-6db low pass filter and synthesised tone

I want to synthesis a harmonic sound with fundamental frequency of f0 and 20 partials with amplitudes of a0, a1, a2, a3 ....a20. The amplitudes should reduce a - 6db per octave like a low pass filter ...
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0answers
13 views

Criteria for Inverse STFT

So far I have studied the STFT and how it works. Following this question: Inverse Short Time Fourier Transform algorithm described in words , I got a grasp of how it works and how to implement it. ...
0
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1answer
19 views

extend parts in an existing audio file to make it sound longer without stretching the file

I'm looking for a way to extend certain parts of an exiting audio file to make these parts sound like the where played longer. And I dont want to change play speed or stretch the file. Lets say u have ...
0
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0answers
36 views

Please explain Multiplication property in Z transform?

I am having problem visualizing contour any example will be great help. As far as as where I need it I was trying to find Z transform of a contracted signal by first multiplication by impulse train.
0
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0answers
29 views

How to reproduce a signal from its decomposed components?

Given a dataset of a signal which has been decomposed into its IMfs (with EMD (Hilbert-Huang transform)), how can synthetic replicas of that signal be reproduced from the decomposed signal? There are ...
0
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1answer
44 views

Frequency modulation audio synthesis: clicks/pops when changing modulator frequency dynamically

I'm very new to DSP and working on a FM VST. It's mostly up and running, or at least it generates FM-like sounds. I want to be able to change various parameters dynamically while audio is generated, ...
0
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1answer
24 views

Choppy output when trying play through a callback buffer

I am trying to make a keyboard in python where every note's frequency is a ratio of the previous note but my output is strangely choppy for some reason. Here's an example of what I mean. I'm using ...
1
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0answers
40 views

Generate time domain signal from frequency domain filter

I am familiar with using the Fourier transform to take a signal from the time domain to the frequency domain. What I would like to do is the reverse: describe a signal in the frequency domain and then ...
0
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2answers
36 views

How to make sure that a sinusoid wave with different subsequent frequencies matches up?

A very basic formula to transform a sequence of notes into a signal would be: $$ x(t) = A\cos( 2 \pi (2^{current\_note}/12) t) $$ where $current\_note$ is $notes[\lfloor t / period\_per\_note\...
0
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1answer
44 views

Glitches in certain frequencies

I am trying to produce some simple audio waves using WASAPI (Windows Audio Session API). If I skip all the abstractions, my program basically receives a buffer from the API, then writes results of a ...
1
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1answer
55 views

Separating two frequency component

How can we separate two frequency component when they get mixed means when signal get mixed with noise how receiver can judge which part is signal and which is noise ?
0
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3answers
162 views

What is the algorithm to do frequency modulation?

I'm familiar with audio synthesis, oscillators etc. I'm now trying to implement my own software algorithm to do FM as described by https://en.wikipedia.org/wiki/Frequency_modulation. What I have ...
2
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1answer
42 views

How is the energy conservation principle preserved in the case mentioned below?

Suppose there are 2 sinusoidal signals $\cos(\omega t)$ and $\cos(\omega t)$, which implies that their individual power is $1/2$ unit and total power is $1$ unit. When added, the signal $2\cos(\omega ...
15
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4answers
2k views

Finding polynomial approximations of a sine wave

I want to approximate the sine wave given by $\sin\left(\pi x\right)$ by applying a polynomial waveshaper to a simple triangle wave, generated by the function $$T\left(x\right)=1-4\left|\tfrac{1}{2}-...
1
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0answers
50 views

Band Limited Impulse Train - DC offset correction

I am trying to get band limited saw-tooth wave. I have found this paper: Alias-Free Digital Synthesis of Classic Analog Waveforms. I am prototyping this code in common LISP, here is snippet of what I ...
-1
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1answer
339 views

relationship of column of spectrogram to original signal

We can get the spectrograms of a signal which is a 2D matrix. How do I get back from the columns of the spectrogram to the time stamps in original signal? For example, what time stamp does the columns ...
1
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0answers
53 views

Bandwidth enhanced sinusoidal model with oscillators banks

i am currently implementing the bandwidth enhanced sinusoidal model for an additive synthesizer, this model allow to accurately produce noisy sounds by adding a noise component to each sinusoids. But ...
0
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2answers
116 views

Controlling a signals amplitude in the frequency domain [closed]

I want to control the amplitude of a signal I'm creating from a user drawn spectrum by scaling the magnitude values in the frequency domain. Here is my scenario. Sample rate $F_s= 44100\textrm{ Hz}$...
12
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2answers
7k views

What are advantages of having higher sampling rate of a signal?

Being a non signal processing science student I have limited understanding of the concepts. I have a continuous periodic bearing faulty signal (with time amplitudes) which are sampled at $12\textrm{ ...
0
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1answer
226 views
-1
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0answers
355 views

Best way to synthesize signal from Power Spectral Density (PSD)

I am looking for methods of synthesizing a random time history signal from a PSD. To me it seems that the simplest method is to take the square root, randomize the phase and then take inverse FFT. ...
0
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2answers
178 views

How should you decide on the number of sweeps to be used in FMCW radar?

I am designing an FMCW radar in MATLAB and I would like to know on how should I decide on the number of linear sweeps in FMCW .Does the number of sweeps affect the performance?
4
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1answer
162 views

Overlapping power-of-cosine windows with constant weight

I would like to refer you to a relevant question I posed on the Math StackExchange: A generalisation of the Pythagorean trigonometric identity. As can be seen from the question and the answer, what ...
0
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1answer
77 views

Convert image of an irregular surface to it's signal equivalent

I want to take the image of an irregular object , say and then I want to convert the elevation of the points into a spatial signal. To make my point clear: the signal would be 'height of the ...
0
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1answer
408 views

Generate loopable sine wave cycle for given frequencies

I am somewhat new to DSP so bare with me. I am working on a simple wavetable oscillator. What I am trying to do is generate one cycle of a wave form for each note (frequency) and store it in an array ...
1
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3answers
545 views

Effect of noise on high and low frequency components

It is given that noise is present in the noisy image in the form of high frequency components. Can any one please explain this concept. Also please tell me that whether it is correct to say that "...
1
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0answers
271 views

What's wrong with my minBLEP Hard Sync Sawtooth code?

I implemented a Sawtooth Oscillator which uses minBLEP - Eli Brandt's original paper The minBLEP approach works very well for a normal Sawtooth but I specifically want to implement Hard Sync and ...
8
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1answer
1k views

How can I decompose a signal into square waves?

I am dealing with signals that are a superposition of different square waves with different amplitudes and phases. Normally, one would decompose a signal into sine waves with help of the Fourier ...
0
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0answers
307 views

Flattening out a power spectral density

The situation is as follows. I am generating a white noise voltage signal with a certain power spectral density amplitude of choice, from 0 to some cutoff frequency, for example 200 MHz. This proceeds ...
-1
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0answers
42 views

Is my approach for Splitting a magnitude across multiple bins correct?

I'm trying to synthesise a sine wave whose frequency is between bin centre frequencies per this post: Splitting a magnitude across multiple bins in an IFFT I'm trying to split my sine's magnitude ...
1
vote
1answer
315 views

Splitting a magnitude across multiple bins in an IFFT

By Georg-Johann own work, CC BY-SA 3.0. I’m trying to synthesise a sine wave using an IFFT at a frequency between bin centre frequencies. Here are the details ...
0
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2answers
551 views

Sine Wave Aliasing during IFFT

I’’m synthesising a simple sine wave using the IFFT. I’m controlling the pitch of the sine wave by controlling the bin number and the phase for that bin number. I’ve synthesised an F whose ...
0
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1answer
71 views

Cascading FM synthesis operations

I'm trying to understand how to program cascading FM synthesis operations. I can find a good deal of information out there on how to do it on various pieces of hardware, but unfortunately, there isn'...
1
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0answers
125 views

Calculating amplitudes of FM Sidebands

How are the amplitudes of FM sidebands calculated? E.g. when negative frequencies are reflected back and their amplitudes added to any existing positive frequencies at that band, how are the ...
0
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1answer
144 views

Bandlimited PWM

Trying to figure out how to synthesize a Bandlimited PWM in my audio code in C. I have already figured out a bandlimited pulse wave but I can't really figure out how to translate that to PWM. I have ...
1
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1answer
103 views

How can I realize a complex communication system in a real time application?

So I am working on a project where I have to model a communication system in MATLAB, then implement it on an FBGA. My transmitter goes something like that: ...
0
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1answer
493 views

Daubechies wavelet transform

i have N samples obtained by sampling a signal with lot of frequency contents. How will i apply daubechies wavelet transform to obtain the frequency and its location? i need to write a program which ...
1
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2answers
639 views

Additive synthesis vs. “just draw the waveform”

I've been experimenting with PYO recently, a Python module for sound synthesis and audio processing. This is really my first foray into this topic, so I have what is probably a very basic question. ...
1
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3answers
488 views

Extrapolation after taking inverse Fourier transform

Suppose I have 2000 point(time series) signal and I take 512 point FFT, after this some operation is done in frequency domain. Now if I take IFFT to get 512 points in time domain, Is there a way to ...
0
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1answer
603 views

adding u(t) and r(t) to create a signal

I previously asked this question in the maths community not realising that this stack exchange community existed. I have searched online extensively and haven't been able to find an explanation to how ...
3
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1answer
106 views

Mysterious notation used in “BLIT” CCRMA paper

I'm working on a project involving synthesizing audio, which led me to a promising Stanford CCRMA paper on band-limited synthesis. However, this double-arrow notation keeps popping up throughout some ...
0
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1answer
99 views

Adding sine waves

I need to play thousands of simple sounds (generated tones) at the same time. If I am understand correctly there should be a way to add them together in complex wave but i really can't see the light ...
2
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2answers
848 views

Integration of square wave

trying to program an integrator. My input is a square wave and my expected output should be a triangle wave. However, whenever I pass it through my low pass filter algorithm (just a 2nd order ...
1
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2answers
88 views

How to represent half of equilateral triangle signal?

How to represent the signal in above image ? I know a ramp signal can be represented by $$x(t) = t\cdot u(t)$$ but here amplitude of that signal is not same with $t$
-1
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3answers
974 views

Extracting a varying DC from a signal

I have a signal that has both AC and DC components and both a re varying with time. How can I extract the varying DC wave from the signal? eg: A PPG (Photopletysmography) signal extracted from a ...
0
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1answer
234 views

IFFT Synthesis from an empty spectrum

I'm trying to generate a sawtooth wave using the IFFT. I can do this successfully by first performing an FFT and then putting that analysed spectrum into the IFFT, however I would really like to be ...
3
votes
1answer
135 views

Controlling one signal with another one (Rocket engine effect - Subtractive synthesis of sound)

I am programming some sound effects in Java and exporting them into .wav files. Currently, I am trying to program a rocket engine sound effect. I want to do it in the following way: The sound of a ...
0
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2answers
7k views

How sine wave is generated using lookup tables

From this document I am quoting P2,L7 So what is the incremental distance if we are using a 64 element look-up table instead of a sine function based on 2π? incremental distance = 2k*64/48k = 8/3. ...