A-weighting filter to lookup table
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hello,
i'm working at an embedded SPL meter, it has to filter out the audio using A-weighting.
I've build a script to test A-weighting filters, but here comes the problem.
My idea is to build a lookup table, that contains the weight value for a specific frequency, then use this table to weighting the signal using fft.
I'm investigating three filters, one build upong the fdesign function, one two using filter coefficients based functions.
I've two question and one problem:
1) is my method correct?
2) what filter table i've to use? if i test it seems that the two coef based filters differs from an offset.
download sample code here: https://www.dropbox.com/s/62ueiv3rmc8l3tc/test.zip
thank you!
1 件のコメント
Daniel Shub
2014 年 1 月 8 日
It is not clear what you are doing, what you are getting, and what you expect. Without this information, it is hard to answer your question.
回答 (4 件)
Wayne King
2014 年 1 月 2 日
How about using
fdesign.audioweighting
if you have the DSP System Toolbox? That will give you A-weighting.
0 件のコメント
Al Hasan
2014 年 1 月 2 日
Hey Davide,
Was your method correct ?
I have attached an image is that A weighted filtering
![](https://www.mathworks.com/matlabcentral/answers/uploaded_files/174164/image.png)
By any chance do you know what they are doing to the above image to get the below image in my attachment, I have data to make the above image dunno how to make the below one from the above
Thanks, Hasan
0 件のコメント
Davide
2014 年 1 月 11 日
1 件のコメント
Daniel Shub
2014 年 1 月 16 日
Okay, and what happens when you run the code? What are you expecting to happen? What would you like to happen? Ideally you should strip the code down to be as minimal as possible. Right now it looks like it should plot 3 figures. If those figures are not related to the problem, don't post that part of the code. You right to an xls file, presumably this isn't the problem. The simpiler the code, the more easily we can help you.
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