Timeline for Signal Processing/FFT gives very high magnitudes for low frequencies
Current License: CC BY-SA 3.0
14 events
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| Apr 13, 2017 at 12:47 | history | edited | CommunityBot |
replaced http://dsp.stackexchange.com/ with https://dsp.stackexchange.com/
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| Mar 3, 2017 at 17:19 | comment | added | skyguy126 | this is it: gist.github.com/skyguy126/2ae918f7457b9f91335d7f51192f8f56 | |
| Mar 3, 2017 at 11:56 | comment | added | Dan Boschen | Where is the new code? | |
| Mar 3, 2017 at 5:43 | comment | added | skyguy126 | Here is the code I am using currently. Could you please take a look at it? The FFT implementation is near the very bottom. | |
| Mar 2, 2017 at 0:00 | comment | added | Dan Boschen | yes i see it now, but it doesn't look much different? | |
| Mar 1, 2017 at 1:41 | comment | added | Dan Boschen | Your updated plot isn't showing up. | |
| Mar 1, 2017 at 1:39 | comment | added | Dan Boschen | I didn't do anything on that path but if you look at the graph I posted above labeled "bank of filters" you can see how the power is conserved across all the bins. If you choose any frequency and took the values in each of the 4 bins and root sum squared them $out = \sqrt{x_0^2+x_1^2+x_2^2+x_3^2}$ you would see that the result would always be 4. In a larger FFT such as yours, most of the energy would be in the adjacent bins, so you could simply root sum square over those to recover most of the signal. | |
| Mar 1, 2017 at 1:30 | comment | added | skyguy126 | I updated the original post. As I said below this is the first time I'm working with signals in general so the results might not be as good. If you could post some example code for this segment "You can recover most of the signal by root sum-squaring the adjacent bins (or all the signal by rss'ing all the bins and displaying this at the max signal location)." it would be very helpful. | |
| Mar 1, 2017 at 0:10 | comment | added | Dan Boschen | (If you do the other methods I think you might need more details on what I did... if interested I can paste the code in my response) | |
| Mar 1, 2017 at 0:09 | comment | added | Dan Boschen | Can you gift us with an updated animation in your posting so we can see the before and after? | |
| Feb 28, 2017 at 23:42 | comment | added | skyguy126 | The window method worked very well and I will try to implement the other methods you mentioned as well. Thanks for the excellent explanation. | |
| Feb 28, 2017 at 14:58 | history | edited | Dan Boschen | CC BY-SA 3.0 |
Added more details on prefilter compensation appraoches
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| Feb 28, 2017 at 1:26 | vote | accept | skyguy126 | ||
| Feb 27, 2017 at 21:03 | history | answered | Dan Boschen | CC BY-SA 3.0 |