I attach the screen shot below. My assumption is what I mark with that green line indicating the height of tone frequency.
- freq.jpg (32.81 KiB) Viewed 170 times
Actual tone frequency
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This forum is for Audacity on Windows.Please state which version of Windows you are using,
and the exact three-section version number of Audacity from "Help menu > About Audacity".
Audacity 1.2.x and 1.3.x are obsolete and no longer supported. If you still have those versions, please upgrade at https://www.audacityteam.org/download/.
The old forums for those versions are now closed, but you can still read the archives of the 1.2.x and 1.3.x forums.
Actual tone frequency
I'm generating a 250 hz tone with audacity 2.1.0 for windows, but when I view on spectogram it seems that the tone's frequency is less than 200 hz. Anyone can explain this?
I attach the screen shot below. My assumption is what I mark with that green line indicating the height of tone frequency.
I attach the screen shot below. My assumption is what I mark with that green line indicating the height of tone frequency.
Re: Actual tone frequency
I don't know, but I trust the tone generation algorithm because it's mathematically simple... There's almost no way the frequency can be off.*
A spectrogram requires FFT and is about 100 times as complicated. And, there are compromises, trade-offs, and and choices (as you can see from the Spectrogram preference options in the menu).
* When you actually play the file, the frequency depends on the accuracy of your soundcard's clock (oscillator). No real-world clock is perfect, but your soundcard won't be off by 25% unless it's badly-badly defective. And the spectrogram analysis is not going through your soundcard.
The tone generation in the digital domain is essentially perfect and as close as you an get with integers. (And the sample rate is just an integer number, so it's value is "perfect" in the digital-data domain.)
A spectrogram requires FFT and is about 100 times as complicated. And, there are compromises, trade-offs, and and choices (as you can see from the Spectrogram preference options in the menu).
* When you actually play the file, the frequency depends on the accuracy of your soundcard's clock (oscillator). No real-world clock is perfect, but your soundcard won't be off by 25% unless it's badly-badly defective. And the spectrogram analysis is not going through your soundcard.
The tone generation in the digital domain is essentially perfect and as close as you an get with integers. (And the sample rate is just an integer number, so it's value is "perfect" in the digital-data domain.)
Re: Actual tone frequency
The frequency is the "brightest" part of the spectrum. With your current settings it only shows that frequency is "somewhere around" 200 to 700 Hz.pohon wrote:My assumption is what I mark with that green line indicating the height of tone frequency.
Increase the "Window size" ("Edit > Preferences > Spectrograms") to about 2048.
- firsttrack000.png (12.61 KiB) Viewed 163 times
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Re: Actual tone frequency
Ah, got it! Thanks Stevesteve wrote:Increase the "Window size" ("Edit > Preferences > Spectrograms") to about 2048.
