alersito

Just this. I would like to know how to calculate the level of an AUDIO IN in dBA. I would like to see the values in third octave 125hz - 20khz and graphically.

how-to-calculate-the-level-of-an-audio-in-in-dba

to get A-weighting you need to filter the input using biquad with these arguments:

{biquad~ 0.49735 0. -0.49735 -1.041289 0.109858]

to get A-weighting you need to filter the input using biquad with these arguments:
{biquad~ 0.49735 0. -0.49735 -1.041289 0.109858]

Terry how do you know the arguments of the biquad object?

Is this the global value?? i would like to know the values in a multislider object like the screen of a sonometer.

I have searched a sonometer patch but i haven't find.

well I just derived them empirically-- you can test the coefficients yourself by plugging the values into filtergraph and see what sort of a curve you get. I did test the filter against a class-A spl meter to see how accurate it was and it seemed to be within less than 1 dB margin of error, which was adequate for my purposes at the time.

as for the other question, you could design a set of cascading fft modules using pfft~, each of which only samples bins 4 to 6 of a different window-size (ie 4096, 2048 ......128, 64), one for each octave

https://cycling74.com/forums/equal-loudness-curves-implementation

but i dont know what is "af Tf Lu" from the patch.

i have seen this post https://cycling74.com/forums/equal-loudness-curves-implementation

but i dont know what is "af Tf Lu" from the patch.


that code is about equal loudness, not A-weight which are completely different things, and it's also written in matlab, which I don't know...af probably refers to amplitude (a) at corresponding frequency (f), but that's just a guess

btw my previous post should read 'bins 3 to 5", not '4 to 6", if you want pseudo 1/3 octave analysis

But if you use 40 fones you are on A-weight, isnt it?

How to calculate the level of an "AUDIO IN" in dBA?