Command Line Options
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Command Line Options
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Command Line Options
ctune history
Version 1.50 benchmarking
Version 1.50 benchmarking
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Accuracy of filter coefficient calculations
Accuracy of filter coefficient calculations
PwrLPF fix
Vectorization using AVX-512, AVX-2 and AVX
New version coming early 2025
The programming problem with sine calculation
Strobe Tuner for Windows
Effect of stage count on bandpass filter response shape
Effect of stage count on bandpass filter response shape
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How to create periodic PCM test tones with high inter-sample peaks
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How good is your PCM sine wave test tone?
How good is your PCM sine wave test tone?
But is it real-time?
SpectrumViewer can read input from a wave file instead of from the Windows audio system. One way to use a wave file is to run spectrumViewer in command line mode. Use the wave= option. You can also just give a filename without the wave= prefix if the filename ends in .wav. To see some examples, try running the batch files in the demo directory. It is possible to use wave file input without using the command line. Find the wave file in Windows explorer and use the right-click option. Then choose SendTo,...
One fix ready for the next release is proper pause mode restoring of the spectrumViewer window after it has been covered by another window. Checking the pause box is essential for doing measurements and making good screenshots. But if you flip to another window to paste a screenshot or to record a measurement, the window doesn't properly repaint itself. This is fixed. Another bug fix is when Ctrl is pressed to activate the crosshair cursor. If the crosshair is moved quickly between the upper and...
The Toro PowerJet F700 corded electric leafblower is an amazing machine in every way except for its speed control. The speeds seem too close together. Today I measured them by recording each speed for a few seconds. Viewing the spectrum shows the fundamental for each step, along with some harmonics: By pressing Ctrl to activate the crosshair cursor, the 1X, 2X, 3X,... pattern of the harmonics confirms than the bottom one really is the fundamental. Next, zoom in to the fundamental to allow a more...
Here are two dithering cases where the spectrum changes drastically: Hover the mouse cursor over each image to see the undithered version. Dithering special cases Here are the sox commands used to make the wave files: sox -D -r16000 -b 16 -e signed-integer -n sox-5to1_nd.wav synth 10 sine 3200 sox -r16000 -b 16 -e signed-integer -n sox-5to1.wav synth 10 sine 3200 sox -D -r16000 -b 16 -e signed-integer -n sox-4to1_nd.wav synth 10 sine 4000 sox -r16000 -b 16 -e signed-integer -n sox-4to1.wav synth...
Electric motor speed measurement from the audio spectrum is easy. While many harmonics are present, only the lowest can correspond to a full revolution of the motor. To demonstrate, I connected a tiny scrap motor from a toy helicopter to a 0-13V power supply. I started recording, then blipped the throttle a couple of times to confirm the motor was working properly. Next, I hit it with 13 volts. The motor is rated for 48,000 RPM (800 Hz) at 3V. The motor actually hit 144,000 RPM before failing. The...
Electric motor speed measurement from the audio spectrum is easy. While many harmonics are present, only the lowest can correspond to a full revolution of the motor. To demonstrate, I connected a tiny scrap motor from a toy helicopter to a 0-13V power supply. I started recording, then blipped the throttle a couple of times to confirm the motor was working properly. Next, I hit it with 13 volts. The motor is rated for 48,000 RPM (800 Hz) at 3V. The motor actually hit 144,000 RPM before failing. The...
SpectrumViewer can read input from a wave file instead of from the Windows audio system. One way to use a wave file is to run spectrumViewer in command line mode. Use the wave= option. You can also just give a filename without the wave= prefix if the filename ends in .wav. To see some examples, try running the batch files in the demo directory. It is possible to use wave file input without using the command line. Find the wave file in Windows explorer and use the right-click option. Then choose SendTo,...
Yes, the numbered scales are needed. But the project went over-budget and didn't make the 1.0 cutoff. For now, press Ctrl to activate the crosshair cursor. As for control labels, I wanted to save screen real estate. Hover the mouse cursor over the control to see its tooltip help.
In the upper left corner, SpectrumViewer shows a FPS (frames per second) number. That number needs to be at least 60 for smooth operation. If the number is less than 60, the CPU is probably struggling with the work load. In certain configurations, the GPU can be the limiting factor. CPU usage is shown in a box within the Status group in the left pane. If the FPS number is less than 60, try these workarounds: Resize the SpectrumViewer app to a smaller size by dragging the lower right corner with the...
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Strobe Tuner for Windows
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Strobe Tuner for Windows
Strobe Tuner for Windows
Strobe Tuner for Windows
Strobe Tuner for Windows
Strobe Tuner for Windows
Strobe Tuner for Windows
Strobe Tuner for Windows
Strobe Tuner for Windows
Strobe Tuner for Windows
Strobe Tuner for Windows
Strobe Tuner for Windows
Strobe Tuner for Windows
Strobe Tuner for Windows
Strobe Tuner for Windows
Strobe Tuner for Windows
Strobe Tuner for Windows