Questions tagged [wave]

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How to calculate a 3D Fourier Transform?

I am currently employing a centered finite difference method to simulate the excitation of a circular membrane by a forcing term in Python, and the code is functioning as intended. To further enhance ...
Manuel Borra's user avatar
0 votes
1 answer
82 views

what am i not doing right while using squarewaves?

I have been applying square waves at 40hz and 10 volts via a function generator amplified by a power amplifier by 2 times(2A) on a 6mm steel specimen. My signals captured from the AE sensor are not ...
Wasil Riaz's user avatar
0 votes
1 answer
93 views

How to generate square wave from sin and cos?

I have a signal that looks almost like a perfect square wave. When looking at its FFT, I see that the real part has components at the fundamental and third harmonic of almost equal magnitudes. When ...
Yaz's user avatar
  • 23
3 votes
1 answer
65 views

What effect causes this Pattern?

I've conducted a measurement of underwater noise in a laboratory experiment. Therefore i am using a sweep signal. Sometimes -I guess when the signal is much more louder- I get this fascinating ...
hoaratius's user avatar
0 votes
0 answers
100 views

How to fit a rectangular wave to a signal?

I have some binary data that mostly comes under the form of a rectangular signal. In order to "idealize" my signal I would like to fit a rectangular wave that best represent my signal (Here ...
NokiYola's user avatar
  • 487
1 vote
1 answer
112 views

How to merge audio better?

I try to use a denoising algorithm to process an audio in streaming mode. What I've done is spliting the audio into 0.5s long segments and use denoising algorithm respectively.Then use np.cat or np....
Killuaisaack's user avatar
2 votes
2 answers
212 views

How to calculate the phase difference between two squarewaves of same frequency but different dutycycle?

I have two squarewaves of the same frequency but with different dutycycle. How can I calculate the phase difference between the two? I know that for sinewaves one can use the correlation coefficient, ...
eeqesri's user avatar
  • 123
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0 answers
18 views

sinusoidal waves for texture similarity

I created an algorithm that approximates the tiny image texture by a series of sinusoids. It is NOT Fourier or discrete cosine because the boundary is highly irregular. I have each wave's frequency, ...
Jakub Mitura's user avatar
0 votes
1 answer
440 views

Resampling to the same sample rate via Python

I'm working on machine learning model and tried to downsample WAV files with Python script, but it didn't work, so I made the simple version - script "resamples" WAV file from 44100Hz to the ...
Kamil's user avatar
  • 3
6 votes
3 answers
1k views

What additional inputs are required to convert dBFS to dB SPL?

It is probably very well known that dBFS cannot be directly converted to dB SPL without knowing other information such as the technical specifications of the microphone. The questions are: What is ...
Miles Fan's user avatar
6 votes
2 answers
423 views

What causes the mismatch between a calculated sine wave and a measured sine wave?

Note: this question has been edited to refer to a sample that does not use dithering. I recently asked my first question on here, about what I saw in an uncompressed audio file written out as integers....
Patrick O'Brien's user avatar
0 votes
2 answers
62 views

Reconstructing a wave which interferes together with a second known one

Is it possible to calculate one of two interfering waves, if the interference (the sum) $v$ and the other wave (summand) $v_1$ is known? The waves have same frequency but may differ in phase and ...
A.Lymphater's user avatar
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0 answers
35 views

Formulas associated with Daubechies Wavelets D2, D3, and D4

I want to knom if there exist any actual formulas for defining Daubechies Wavelets D2, D3 and ...
konmi's user avatar
  • 101
-1 votes
1 answer
189 views

Inverting (spectrogram vertical flip) a signal of WAV file

What I need is to invert a signal (on spectrogram it would look like a vertical flip) of a WAV file. Actually, of a bandpass of a signal - from 500 to 800 Hz, for example. This image will perfectly ...
Ivan G's user avatar
  • 1
0 votes
1 answer
254 views

Return list of wav files in folder that are clipped

Is there any method via python of any other means, to return a list of wav files in a folder that are clipped? I know that Adobe Audition can tell if a file is clipped, but I have to open up each file ...
Joe's user avatar
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1 vote
1 answer
78 views

Is the magnitude of the phase shift independent of the volume of the sound?

Sound waves can cause vibration of the particles/objects that are scattering/reflecting/emitting the light. Since vibration is spatial displacement, it causes a phase shift by affecting the value of &...
Kevin's user avatar
  • 19
4 votes
1 answer
170 views

Estimation of the attenuation of two waves on a linear sensor array

Context and objective I am trying to estimate the attenuation coefficients ($\alpha_u$ and $\alpha_v$) of two waves ($\overrightarrow{u}$ and $\overrightarrow{v}$). These waves propagate on a linear ...
User327201's user avatar
1 vote
0 answers
54 views

Envelope of a series of pulsed signals [duplicate]

I need to record a series of pulse waves for an experiment. The recording is done via Software Defined Radio (GNU Radio). The pulse waves are modulated in such a way that the amplitudes of each single ...
thehnm's user avatar
  • 11
0 votes
1 answer
74 views

How to obtain the wave height "H" /wave period T from the spectral density S(f)

I have the equation of the power spectral density $S(f)$. I seek $(H,f)$ of each sinusoid which $H$ is the magnitude and $f$ is the frequency. How to calculate $H$ from $S(f)$? $S(f)$ is the spectral ...
Tarek Hadj Hassen's user avatar
-1 votes
1 answer
72 views

How to inject a 2D plane sine wave to the array of seismic sensors?

I've several sensors positioned at various points in the $X$,$Y$-Cartesian coordinate system, and I've experienced a problem to inject a planar Sine wave to the spatially positioned sensors, the ...
Alan22's user avatar
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1 vote
0 answers
20 views

What is meant by discrete time plot with Whatsapp voice notes? [closed]

You might have noticed ,as shown highlighted in attached snap, whatsapp voice notes are bearing a discrete time plot Is it exactly referring to sampled(discrete time)version of waveform of actual ...
DSP_CS's user avatar
  • 1,850
2 votes
4 answers
381 views

Finding the mode of propagation of a progressive wave and the velocity of that mode

Injecting a sinusoid say, $Z = A \sin(k_x X + k_y Y - \omega t)$, $K = 2 \pi f/c$, for example, assume $f = 10$ Hz or $50$ Hz, and $c = 50$ m/s, now if I draw the 2D K-space plot with the following ...
Alan22's user avatar
  • 21
4 votes
2 answers
381 views

How are sounds recorded and reproduced (played back)?

Someday I have suddenly got wondered how sounds are recorded and reproduced. I searched a little bit but the information I got was composed of difficult words and contents, so I couldn't understand ...
Doohyeon Won's user avatar
2 votes
1 answer
111 views

Why can't millimeter waves travel far [closed]

So I was digging around 5g technology, and apparently, many people say that high-band 5g can't penetrate buildings, trees, even rain. However, the atmospheric attenuation around 30 GHz does not seem ...
157 239n's user avatar
  • 123
0 votes
1 answer
3k views

How to extract the dominant frequency from the audio WAV file using numpy

So, I recorded this audio on my phone while I was running a tone generator on my PC at a frequency of 13Khz, now I want to extract this frequency which is dominant from the recorded ...
iwrestledthebeartwice's user avatar
0 votes
1 answer
273 views

Why does a wave composed of two waves have an FFT with only one peak?

I am trying to find a value from a given mathematical function whose input is supposed to be derived from FFT components. Essentially, I follow the procedure from [1] which assumes that a given sine ...
user244717's user avatar
0 votes
0 answers
79 views

Reflected wave in FFT?

I'm trying to determine the reflective coefficient of sine wave. This one paper suggests a method using Fourier analysis. Here, it suggests Incident Wave = a cos(kx + Constant1), Reflected Wave = a ...
user58500's user avatar
1 vote
1 answer
31 views

Resources for the Basics on Signals and Electromagnetic Waves in the radio frequencies [closed]

What are some good books and videos, to learn about radio waves? For someone (me) who has never studied Math, Physics, or anything people generally consider ‘technical’.
David's user avatar
  • 131
3 votes
1 answer
172 views

Wave Digital Filter Bridge-T Resonator implementation, gives expected cutoff frequency but incorrect gain and roll-off

Trying to implement the WDF in Fig 5(a) of this publication. The response of the ideal op-amp implementation is given by the black curve in Fig 7: Here is the plot I get when trying to implement the ...
Nick Nagy's user avatar
0 votes
0 answers
163 views

Efficient Method for Interpolating between bins in FFTW

I'm working on some oscillator classes right now and perform FFT around 100 times per second. The issue I'm running into is interpolating between the bins so there is not a noticeable change from each ...
Sean's user avatar
  • 1
0 votes
1 answer
57 views

Playing sounds with only one frequency at a time

We have a "speaker", that can make a single frequency at a time (0 - 130k Hz). So we can play a tune by making it play a tone for 1 sec and then the next tone for 0.5 sec etc. We can change ...
DrDress's user avatar
  • 103
4 votes
0 answers
246 views

Wave Digital Filter Diode Equation?

I'm trying to understand how diode circuits are implemented in wave digital filters, particularly for clippers. The research papers and other sources I've looked at use the equation $$I(V) = 2I_s \...
Nick Nagy's user avatar
2 votes
2 answers
3k views

DFT of pure sinusoidal wave

I'm writing a program in which you can synthesize waves by adding to a sound's Fourier transform, and then inverse the transform to get the modified sound. In order to do this, I need to know what to ...
Verpous's user avatar
  • 121
1 vote
2 answers
1k views

How to merge 2 WAV files together? Can I take the average of the 2 audio file float values? [duplicate]

I'm trying to do one simple thing on Google's C++ Oboe library: pick 2 recordings and merge both. That is, make as if the 2 were playing at the same time. Oboe works with Float numbers from -1.0 to +1....
Guerlando OCs's user avatar
4 votes
4 answers
1k views

Reconstructing a sine wave from an interval shorter than half its wavelength

I know that the function that I search is a sine wave of the form $$A \cdot \sin(x) $$ where my $A$ is unknown. I have samples of the sine wave at discrete points within an interval that's shorter ...
Bulbasaur's user avatar
  • 207
1 vote
0 answers
147 views

Hello World Example of a Digital Waveguide in JavaScript

I am just learning about sound so might be jumping the gun a bit. But it helps me stay motivated and get into an interesting problem to solve to ask these more complicated questions. I am looking at ...
Lance's user avatar
  • 111
0 votes
2 answers
109 views

What do troughs represent in a sound wave?

What's the notion of negative amplitude? I hope the title and the question don't mean different things.
Devashish Jaiswal's user avatar
0 votes
1 answer
485 views

What is the actual format of this audio file?

I am collecting some data from jotform .wav widget. All the audio files are in .wav format. But when I tried to open the file using python ...
Aaditya Ura's user avatar
1 vote
3 answers
75 views

How does voice affect a sound wave or its corresponding waveform?

Someone in the physics stack exchange told me to come here for this question. My question is how does a person's voice affect how a soundwave looks? For example, if I say the letter "a" it ...
M S's user avatar
  • 11
2 votes
1 answer
516 views

Does Radio Communication Have to Account for the Doppler Effect?

I know that radio communications take place in specific frequency bands, and that the doppler effect can cause shifts in frequency when there is relative motion between the source and destination ...
Matthew Inbox's user avatar
0 votes
1 answer
88 views

harmonic waves as integer multiple in spectrum

i have a motor that is rotating with a certain frequency. If i check the frequency spectrum it contains a peak on 150 hz. Also i have peaks at 300,450,600 ... i guess that those peaks are harmonics. ...
Khan's user avatar
  • 141
0 votes
1 answer
847 views

Harmonics in Matlab

...
Oğuzhan Kırlar's user avatar
1 vote
2 answers
845 views

Types of interpolation used for reconstruction in DSP?

What are the different types of interpolation used in DSP for reconstruction of analog signal from discrete/digital signal I am able to somehow learn two types of interpolation 1st is "zero order ...
DSP_CS's user avatar
  • 1,850
0 votes
1 answer
209 views

How to Save FFT output for fast read-in?

For a project, I'm reading in hundreds of short (4 sec) wavefiles and giving them to scipy fft for the frequency information for further processing/experimenting in various ways. Problem is, I want to ...
biathlonc's user avatar
1 vote
0 answers
19 views

Digital signal processing how audio wave and function chage with respect to each other

If an audio signal is f(t) and if i play same audio with 2× speed then what will function of 2× speed signal f(2t) or f(t/2) and why?
Parag Jain's user avatar
-1 votes
1 answer
128 views

Mix N sinusoidal waveforms without clipping but at a costant amplitude with no clipping and maximum amplitude

I need to mix "n" sinusoidal waveforms which can be all active or some or all can be silent. The math seemed simple (working with float32 samples) because I just added all waveforms and then divide ...
Zibri's user avatar
  • 99
0 votes
0 answers
127 views

Clip wav by PSD

I have the following two things. sequence_1: Sound file in the wave format. PSD_1: Some PSD (Power Spectral Density). I want that the PSD(sequence_1) < PSD_1 for all indices. How I think about ...
Reto Weber's user avatar
1 vote
1 answer
127 views

Where should triangle, sawtooth and square waves start?

I am reading a text on DSP, which shows generation of sin, cos, triangle, sawtooth and square waves. Generated cos waves start at 1 and sin waves start at 0, which makes sense (cos(0)=1, sin(0)=0). ...
Lars Ericson's user avatar
0 votes
0 answers
60 views

Need help with detecting onset of audio in wav file

I'm new to DSP and I'm learning as I go. I have an audio file with a chirp signal(2kHz). I played and recorded this chirp signal and the recording has a lot of environmental sounds. Here is my code:
PhoenixProject's user avatar
3 votes
2 answers
302 views

Why do waveforms that are symmetrical above and below their horizontal centerlines contain no even-numbered harmonics?

All About Circuits site states that waveforms that are symmetrical above and below their horizontal centerlines contain no even-numbered harmonics. Can somebody explain this mathematically, or point ...
robert's user avatar
  • 133