8
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Precise 5th and 7th harmonics of a sampled sine wave
This answer discusses the harmonic spectra of the quantized sequence in five cases:
limit $f/f_s \to 0$,
synchronous sampling of a cosine with rational $f/f_s$,
synchronous sampling of a sinusoid of ...
- 13.7k
5
votes
Accepted
Group Delay for Hilbert Transformer and Resulting Dispersion
A real-valued system that doesn't distort the shape of the input signal must have the following input-output relation:
$$y(t)=Ax(t-t_0)\tag{1}$$
with arbitrary real-valued constants $A>0$ and $...
- 92.5k
5
votes
Can someone explain waveshaping to me?
In the audio domain, waveshaping is simply applying a memoryless nonlinear function to an input signal.
$$ y(t) = g\big( x(t) \big) $$
The waveshaping function, $g(x)$, is most often a continuous ...
- 21.4k
5
votes
Digital modelling of circuits with diode (i.e. guitar distortion)
One possible tool is Wave Digital Filter analysis which is a type of physical modeling that represents signals as travelling waves. It can also be extended to non-linear elements such as diodes.
...
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5
votes
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Group delay compensation for non coincident drivers
For the first question, given the linear process, what you do to the sum with regards to filtering is equivalent to what you do to each and then sum.
For the second question, the dip is in the ...
- 55k
4
votes
Accepted
Create distortion from basic linear (and non-linear if neccessary) DSP elements
Using those four basic elements will allow you to implement linear systems, which can change the magnitude and phase of the input signal, but which will not add the harmonics that are expected from a ...
- 92.5k
4
votes
Group delay compensation for non coincident drivers
I'm not sure whether this is a purely academic exercise or supposed to do something useful in the real world. Assuming it's the later, there are a few additional points to consider
Typically when ...
- 48.2k
4
votes
Nyquist frequency Plotting Distortions
It's simply a drawing artifact. You are plotting the wave form by connecting the individual samples with straight lines. That's wrong.
The values between samples can be determined through sinc ...
- 48.2k
4
votes
What measures are used to identify a faulty speaker?
Faultiness in the sense of mechanical damage is commonly referred to as "Rub and Buzz" distortion. It can be caused by loose particles, rubbing of the voice coil on something else, voice ...
- 2,383
3
votes
Precise 5th and 7th harmonics of a sampled sine wave
The harmonics will be in the range of -150dB to -170dB. The exact value will depend on exact frequency, phase relationship to sampling frequency, phase locked or unlocked, rate of phase drift, ...
- 48.2k
3
votes
Accepted
Digital modelling of circuits with diode (i.e. guitar distortion)
if you treat the diodes as having memoryless non-linear volt-amp characteristics and treat the capacitor as linear and having memory, you can use Euler's backward method to represent the capacitors ...
- 21.4k
3
votes
Accepted
Regarding the advantages of generalized linear phase filters
Note that with the definition of generalized linear phase $\phi(\omega)$ according to
$$H(e^{j\omega})=|H(e^{j\omega})|e^{j\phi(\omega)}\tag{1}$$
and
$$\phi(\omega)=\alpha\omega+\beta\tag{2}$$
the ...
- 92.5k
3
votes
Accepted
If a filter has a non-linear phase lag will the output signal be distorted?
I think your question comes from several misunderstandings. The fact that the phase lag of a system becomes more negative for large frequencies does not mean that there's more distortion of larger ...
- 92.5k
3
votes
Accepted
Fixing integer overflow in wave file
What you have there is "wrap around" and a bad case at that.
It's easy enough to fix though. Let's call your samples $x[n]$ and your max amplitude $x_{max}$, so your signal is currently ...
- 48.2k
3
votes
Accepted
How to avoid harmonic distortions in a DAC?
Frequency Planning in Radio Design
The OP has clarified in comments that his question is focused on what would I believe would be commonly referred to as frequency planning in the process of radio ...
- 55k
3
votes
What kind of distortion effect is this?
If a sine wave was going in, because of the asymmetric waveshape coming out, it can't be a straight memoryless waveshaper. The half wave coming out looks the impulse response of an overdamped or ...
- 21.4k
2
votes
Accepted
How to analyze image quality?
You are apparently in the context of no-reference, reference-free or blind image quality assessment. The topic is quite active, and I am not sure people have already a completely accepted framework ...
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2
votes
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Can IR emitter signal be distorted by curved glass housing around receiver?
Short answer: No.
Long answer: you can of course create shadowing that way, and that would disturb operation. And of course, a glass wall will refract infrared just as it refracts any other light. ...
- 32.5k
2
votes
Accepted
Redistributing Color in a RGB Image According to a Gaussian Distribution
After you equalize the histogram you can think of your data as a stream of variables $ {X}_{i} $ where $ X \sim U \left[ 0, 1 \right] $.
Now all you need is to transform samples of Uniform Random ...
- 20.5k
2
votes
Accepted
Norm MPEG-1 Layer III (Mp3) Filter banks distortion
I have tested your code.
There are problems with the decimation and upsample stages. When you run the analysis and synthesis filters at the undecimated rate, then you get the perfect reconstruction (...
- 28.4k
2
votes
Accepted
Linear vs Non linear distortion
The Wikipedia article on "distortion" is actually pretty good. https://en.wikipedia.org/wiki/Distortion
Partially it's about semantics and how you exactly define the term. By most definition "linear ...
- 48.2k
2
votes
How to prevent distortion after down-sampling?
Read up on the sampling theorem, e.g. https://en.wikipedia.org/wiki/Nyquist%E2%80%93Shannon_sampling_theorem
If your feature vectors are still in the time domain and linearly derived from the ...
- 48.2k
2
votes
Can harmonics be created or simulated a la carte
The answer is "sorta". Lot's of assumptions, though. This is related to that other question where you've been.
This is about waveshaping of a single sinusoid (without harmonics) by ...
- 21.4k
2
votes
Can harmonics be created or simulated a la carte
Without re-hashing all of the maths from RBJs response, I made a crummy little plug in that did more/less what you are proposing. It had a stupid simple GUI with one slide for nominal amplitude and ...
- 1,038
2
votes
Fixing distortion in photographic reproductions
I answered a related question in SO some time ago. Briefly, you can work your setup through a standard camera calibration procedure, and you have the option of "freezing" the focal length to ...
2
votes
Accepted
Nyquist frequency Plotting Distortions
One way to avoid low time resolution is to upsample signals before whatever processing.
To answer this question I have modified the Mathworks example that downsamples DAB (audio) signals to match DVD (...
2
votes
Troubleshooting distortion in room impulse response measurements:
TL;DR
The so called (not the actual term used in bibliography though) "ghost sweeps" are absolutely normal!!!
Information
The method is termed Exponential Sine Sweep (ESS) and was pioneered ...
- 1,484
2
votes
Accepted
Is this a noise or what? (Sinusoidal signal frozen for a short time)
Mathematically, we have this relationship:
$$\cos(2\pi f_1 t) + 2\sin^2(\pi f_1 t) = 1$$
I don't suspect the OP is actually observing additive noise (although any deviation from the expected signal ...
- 55k
2
votes
What exactly is transmitted in the channel in lossy compression?
The rate distortion theory simply doesn't answer the questions you ask if how you do it.
It does answer questions like "is this rate sufficient to get things across with at most distortion D"...
- 163
2
votes
Accepted
Correct geometrical distortions from camera
Simply, you need to undistort your images first to correct the fish-eye distortion. Then, align your image plane to be coplanar with the table.
Both of the mentioned operations are geometrical ...
- 1,417
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