Questions tagged [distortion]

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What measures are used to identify a faulty speaker?

I'm working on building a mobile app that would play a sound via speaker, record itself and process this recording to identify faults within speakers, what meastures or parameters should be considered ...
Priyank Joshi's user avatar
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1 answer
30 views

Can a bad quality sound be measured via THD?

I'm trying to create an app that measures the audio quality, this is ideally to filter out blown out or cracking speaker who has different types of distortions, what would be the best measurement ...
Priyank Joshi's user avatar
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1 answer
23 views

Constraints in Dynamic Time Warping for Speech

The Dynamic time warping is applied for time normalization. As shown in the diagram, two different signals with $Tx$ and $Ty$ time instants, are time-normalized to have $T$ time instants. $\phi$ is ...
Anantha Krishnan's user avatar
2 votes
2 answers
104 views

What exactly is transmitted in the channel in lossy compression?

Consider the problem of lossily compressing a memoryless binary source $X \sim \operatorname{Bernoulli}\left(\frac{1}{2}\right)$ at target Hamming distortion $D < \frac{1}{2}$. According to the ...
nalzok's user avatar
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4 votes
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Distortion-Rate function for standard Gaussian signals quantized with a uniform alphabet

Let's say $X \sim N(0, 1)$ is a standard Gaussian input signal and $Y \sim U\{y_1, y_2, \cdots, y_{16}\}$ follows a discrete uniform distribution (in fact, $\{y_1, y_2, \cdots, y_{16}\}$ is a ...
nalzok's user avatar
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0 answers
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Channel Estimate for OFDM shows distortion for first last order samples

The Channel Gain Estimation was obtained using Least Square method as follows: Hk= mean(Rx_LTS ./ Tx_LTS, 2); k= -26 to 26 Where Rx_LTS is the received long training sequence (52 samples after ...
Walkürie's user avatar
0 votes
1 answer
97 views

What kind of distortion effect is this?

Here is the image of a plugin distortion I have applied to a sine wave. The sound characteristic is heavily distorted and digital but still good sounding bass wave. Any ideas what kind of distortion ...
TiagoLr's user avatar
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1 answer
70 views

Stream gate - removing samples from timeline. Pitfalls?

I'm working with gnuradio. What I want achieve is extract signal from full stream by some kind of stream gate (based on tags) and after that write to file only timeline where signal exists. In my case ...
brz's user avatar
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1 vote
1 answer
82 views

Is this a noise or what? (Sinusoidal signal frozen for a short time)

I am studying a pair of AC signals for voltage and current. In a long run, I found a distortion happening as shown in the attached picture. I want to understand what could possibly have happened in ...
Woody Wu's user avatar
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3 votes
0 answers
103 views

Calculating THD vs. Frequency of an Acoustic System using the Exponential Swept Sine Method

I am working on analyzing the total harmonic distortion (THD) vs. frequency curve for an acoustic system. I am aware of the traditional method of exciting the system with a mono-frequency wave and ...
DSP novice's user avatar
1 vote
1 answer
253 views

DSP function used by musical distortion plugins

In short: what kind of mathematical function was applied to this sine WAVE? I am trying to implement my own distortion plugins. Amongst other things I have read several chapters of Will Pirkle's book (...
adrienbourgeois's user avatar
5 votes
2 answers
521 views

How to avoid harmonic distortions in a DAC?

I have a DAC which is assumed to be nonlinear, such that it produces unwanted harmonic distortions at integer multiples of the input frequencies. (EDIT: Any other nonlinear distortions, such as ...
Harry's user avatar
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3 votes
1 answer
228 views

Troubleshooting distortion in room impulse response measurements:

I am collecting data for a project, where I am measuring the room impulse response by playing a sine sweep from a speaker (QSC K8 1KW Active Loudspeaker) and measuring it from the other side of the ...
Mason Wang's user avatar
1 vote
0 answers
58 views

WAV file audio sync/distortion issue

I was using Scarlet 2i2 audio interface plugged into an Android phone. Monitor headphones on the interface sounded great! I recorded a WAV file of a kids' concert with the USB Audio Recorder Pro app, ...
Gregory Klopper's user avatar
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1 answer
39 views

Strange Look to Sampled Sinusoid [duplicate]

Ok so as part of a project for school I have been designing an FIR bandpass filter. The output should have been a signal which looks like a sampled sinusoid but there was a strange alteration on the ...
RickarySanchez's user avatar
1 vote
2 answers
84 views

Nyquist frequency Plotting Distortions

I'm trying to plot some sinusoidal signals in Matlab. But while frequency is getting higher (closing to fs/2), results are getting distorted. I guess it's lack of my knowledge but distortion is ...
BugraKezan's user avatar
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2 answers
52 views

Fixing distortion in photographic reproductions

I am currently building a photographic setup which I intend to use to make reproductions of a large amount of transparencies(positive and negative film strips). As I will be using a fairly small (1&...
MTTI's user avatar
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3 votes
1 answer
227 views

Advice on seperation of impulse responses for harmonic distortion orders

I am working based on Angelo Farinas paper: Simultaneous measurement of impulse response and distortion with a swept-sine technique. The purpose of the work is part of a loudspeaker measurement and ...
Jammus's user avatar
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5 votes
2 answers
416 views

Group delay compensation for non coincident drivers

Suppose I have a two-way speakers system which can be modeled as a two-way Linkwitz-Riley crossovers network with impulse responses $h_{lp}(n)$ and $h_{hp}(n)$. I would like to equalize the group ...
Spark123's user avatar
2 votes
1 answer
189 views

What happens when filter ringing is far longer than the signal itself?

I'm digging into some (quite popular in my field) analytical practice that I find suspicious. The problem is to remove the trend from some very short (eg. 18-40 data points representing 200 - 800 ms) ...
Bartek Kroczek's user avatar
0 votes
1 answer
98 views

Signs of waveshaping polynomial coefficients

I'm playing with some basic functions for distortion purposes. Odd order polynomials generate odd harmonics, even order polynomials generate even harmonics. When I combine them, both types occur at ...
someoneunimportant's user avatar
1 vote
0 answers
47 views

Deconvolution of signal with harmonic distortion

I came across these measurements done using a stepped sine sweep covering only some frequencies (~800 frequency points). I would like to get an impulse response from these measurements to convolve ...
justDSP's user avatar
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0 answers
137 views

Emulating tape distortion of low-level audio signals

I'm working on a tape echo emulation in Reaktor, and I've based the frequency response, tape speed warble, high-amplitude saturation and tape hiss on a paper I found about the Roland Space Echo. ...
Reaktor4's user avatar
-1 votes
1 answer
68 views

Error correcting code? - using RGB space with a lookup table

This problem could be thought about as how to transmit a signal with 3x8bit RGB in a way that is robust to the distortion of antialiasing blends colors. The context: I need to rewrite a short utility ...
exrhizo's user avatar
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1 answer
69 views

High FIR order in time critical classification task

I have a question regarding filtering (bandpass in my case) as a preprocessing step before a classification task. The frequency band I am interested in lies between 0.5 - 22 Hz which results in a ...
handsitter's user avatar
1 vote
2 answers
253 views

Can harmonics be created or simulated a la carte

I am trying to learn about adding harmonics (audio) with a goal to make a plugin that can allow adjustment of the amplitude of each harmonic being added. I would not have the ability to write this but ...
Tzodmusic's user avatar
1 vote
1 answer
102 views

Fixing integer overflow in wave file

I have this recording from my DAW that showed a strange form of distortion: the signal clipped at many places, but instead of simply being clipped (loss of information), somehow the integer value of ...
sleblanc's user avatar
  • 113
5 votes
1 answer
131 views

Finding the Transfer Function of a Multiplicative Distortion in MATLAB

I have the frequency response of two signals shown above. One is uncontaminated, and the other is the same signal contaminated by a multiplicative distortion with two poles and two zeros. I need to ...
jmcd's user avatar
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3 votes
0 answers
1k views

How does image rotation affect the intrinsic camera parameters?

I am considering the problem of how to (manually) change camera model parameter to make it "valid" on a rotated image. This question tackles resizing, but does not consider lens distortion. ...
oarfish's user avatar
  • 81
2 votes
2 answers
387 views

Exponential Swept Sine Distortion

I was able to get passable results on fundamental measurements using and exponential swept sine. Now I am trying to get distortion information from the same measurement but am puzzled by the results. ...
NatanBackwards's user avatar
1 vote
1 answer
58 views

Signal distortion under non-linear channel

The channel is given to have these characteristics, and its required to study the affect on Frequency Modulated signal and its demodulation. Since there are no sharp corners (like during clipping) ...
Tanya Choudhary's user avatar
-1 votes
1 answer
1k views

What function to apply a Metamorphopsia (grid warp) translation?

How would I go about finding or creating a function to warp images dependent on grid lines surrounding an origin (I don't wish for a grid on my actual images): It should work in practically the same ...
bemzoo's user avatar
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0 votes
1 answer
163 views

Understanding legacy code: Algorithm to remove radial lens distortion

The method below to remove lens distortion from a camera was written more than ten years ago and I am trying to understand how the approximation works. ...
tenminutemail's user avatar
0 votes
1 answer
197 views

Total Harmonic Distortion THD for the rectifier

I have a circuit with rectifier and this cause the non-linearity and consequently harmonic. I show it on the oscilloscope and then collect the signal from the oscilloscope to the computer by using the ...
SnowMan's user avatar
5 votes
1 answer
458 views

Group Delay for Hilbert Transformer and Resulting Dispersion

An ideal Hilbert Transformer shifts the phase for all positive frequencies by $-\pi/2$ and all negative frequencies by $+\pi/2$ while maintaining constant magnitude everywhere. Group Delay is the ...
Dan Boschen's user avatar
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0 votes
1 answer
218 views

How to quantify phase distortion of a filter specific to a signal?

For example, a EKG input signal is filtered with a known transfer function that does not have linear phase. How do you quantify the phase distortion of the output signal given you have the input? I ...
pproctor's user avatar
1 vote
1 answer
1k views

How to prevent distortion after down-sampling?

I am new to audio signal processing, but in one of my machine learning projects that I am working on, I need to down-sample my audio somewhere in the middle of my neural network. Therefore, I need a ...
Raven Cheuk's user avatar
0 votes
0 answers
1k views

How to measure SINAD of an audio signal?

I tried to measure the SINAD and SNR of a recorded audio signal using MATLAB. The following is the process I did to measure the 2 parameters: Firstly, I generated an FM modulated signal(1 kHz audio ...
Ram's user avatar
  • 1
2 votes
1 answer
260 views

Distort voice to hide talker identity as much as possible

I need to develop an app which makes speech recognition. Because I need to be able to constantly improve the recognition capability, I would like to train the engine with real recordings and match the ...
Ivano85's user avatar
  • 21
0 votes
1 answer
258 views

Recommendations for SINAD equipment

I am interested in buying a device that measures the SINAD of the audio signal(FM signal) that I receive from PC. Here is the setup: Signal generator (generating 1kHz FM signal ) $\rightarrow$ ...
Ram's user avatar
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0 votes
0 answers
21 views

Any recommendations for buying SINAD measuring equipment? [duplicate]

I am interested in buying a device that measures the SINAD of the audio signal(FM signal) that I receive from PC. Here is the setup : Signal generator -> attenuator ->HackRF connected to PC with SDR# ...
Ram's user avatar
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1 vote
1 answer
801 views

Linear vs Non linear distortion

I'm learning about distortion and I got stuck at "What is the difference between linear and non-linear distortion?" (Also in frequency spectrum i.e. Amplitude and phase spectrum)
Avinash Baldi's user avatar
5 votes
3 answers
1k views

Precise 5th and 7th harmonics of a sampled sine wave

Does anyone know in decibels (to 1/100th of a dB) what the theoretical 3rd, 5th and 7th harmonic of a 0dB fs 24-bit (i.e. full-level; 0dB = -8,388,607 to 8,388,607) sampled sine wave without dither ...
Richard's user avatar
  • 101
1 vote
1 answer
642 views

Can I use SINAD for THD+N measurements? Are they inverse of each other?

I'm looking for a clarification, which I haven't really been able to find. It's probably obvious but I'd like to be absolutely sure of what I'm calculating. I noticed that the formula that calculates ...
Aditya TB's user avatar
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0 votes
2 answers
60 views

Audio sounds oddly distorted [closed]

https://clips.twitch.tv/TangentialObliqueLobsterSaltBae https://clips.twitch.tv/CharmingBashfulAlfalfaRickroll https://clips.twitch.tv/NaiveKindGorillaGivePLZ (Disclaimer: These were not recorded on ...
Lord Nazo's user avatar
-1 votes
1 answer
298 views

Finding the memory polynomial model coefficients

I want to build a memory polynomial model given that I know the corresponding output signals for known input signals. What is the easiest way to find the coefficients of it? And how do we take the ...
sudheer naidu's user avatar
0 votes
1 answer
512 views

Dithering adds harmonic distortion after filtering and upsampling

I have an issue which I wasn't able to solve for a few days. I have implemented a polyphase FIR interpolation filter within an FPGA which does interpolate by a factor of 8 or 16 times. I do accept an ...
xc3s50an's user avatar
0 votes
2 answers
166 views

Why is distorted / quantized white noise still white noise?

White noise can be created by setting every sample in the time domain to a random number with a gaussian distribution. Every sample is random, so the frequency response is obviously random. Easy ...
usernumber's user avatar
3 votes
1 answer
692 views

Identify the Type of Image Distortion (On Lena Image)

I want to understand the distortions in each of the lena images shown in the image below. I see that the first one is a blur. How can undo the blur. The second one is colored salt and pepper noise. ...
Pete's user avatar
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0 votes
1 answer
80 views

THD requirement for generated sine

I need to generate a sine signal using a DAC with a certain THD specification, say 0.1% @ 1KHz. As a first approach I’m considering it to be an ideal DAC along with an ideal LPF for aliasing removal ...
PDuarte's user avatar
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