Cycling 74 » Topic: How to calculate the level of an "AUDIO IN" in dBA? http://cycling74.com/forums/topic/how-to-calculate-the-level-of-an-audio-in-in-dba/feed Wed, 19 Jun 2013 15:31:57 +0000 http://bbpress.org/?v=2.2.4 http://cycling74.com/forums/topic/how-to-calculate-the-level-of-an-audio-in-in-dba/#post-58475 <![CDATA[How to calculate the level of an "AUDIO IN" in dBA?]]> http://cycling74.com/forums/topic/how-to-calculate-the-level-of-an-audio-in-in-dba/#post-58475 Sun, 14 Aug 2011 17:40:45 +0000 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.

Its possible??

thanxxxx!

]]> http://cycling74.com/forums/topic/how-to-calculate-the-level-of-an-audio-in-in-dba/#post-210127 <![CDATA[Re: How to calculate the level of an “AUDIO IN” in dBA?]]> http://cycling74.com/forums/topic/how-to-calculate-the-level-of-an-audio-in-in-dba/#post-210127 Mon, 15 Aug 2011 00:51:17 +0000 Floating Point 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]

then get the rms value over 125ms

]]> http://cycling74.com/forums/topic/how-to-calculate-the-level-of-an-audio-in-in-dba/#post-210128 <![CDATA[Re: How to calculate the level of an “AUDIO IN” in dBA?]]> http://cycling74.com/forums/topic/how-to-calculate-the-level-of-an-audio-in-in-dba/#post-210128 Mon, 15 Aug 2011 10:13:08 +0000 alersito 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.

My object is create a sonometer.

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

]]> http://cycling74.com/forums/topic/how-to-calculate-the-level-of-an-audio-in-in-dba/#post-210129 <![CDATA[Re: How to calculate the level of an “AUDIO IN” in dBA?]]> http://cycling74.com/forums/topic/how-to-calculate-the-level-of-an-audio-in-in-dba/#post-210129 Tue, 16 Aug 2011 10:22:13 +0000 alersito nobody?

]]> http://cycling74.com/forums/topic/how-to-calculate-the-level-of-an-audio-in-in-dba/#post-210130 <![CDATA[Re: How to calculate the level of an “AUDIO IN” in dBA?]]> http://cycling74.com/forums/topic/how-to-calculate-the-level-of-an-audio-in-in-dba/#post-210130 Tue, 16 Aug 2011 11:46:44 +0000 Floating Point 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

T

]]> http://cycling74.com/forums/topic/how-to-calculate-the-level-of-an-audio-in-in-dba/#post-210131 <![CDATA[Re: How to calculate the level of an “AUDIO IN” in dBA?]]> http://cycling74.com/forums/topic/how-to-calculate-the-level-of-an-audio-in-in-dba/#post-210131 Tue, 16 Aug 2011 12:52:25 +0000 alersito i think that i need to learn more. (^_^)

i have seen this post http://www.cycling74.com/forums/topic.php?id=13899

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

]]> http://cycling74.com/forums/topic/how-to-calculate-the-level-of-an-audio-in-in-dba/#post-210132 <![CDATA[Re: How to calculate the level of an “AUDIO IN” in dBA?]]> http://cycling74.com/forums/topic/how-to-calculate-the-level-of-an-audio-in-in-dba/#post-210132 Tue, 16 Aug 2011 13:44:34 +0000 Floating Point 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

]]> http://cycling74.com/forums/topic/how-to-calculate-the-level-of-an-audio-in-in-dba/#post-210133 <![CDATA[Re: How to calculate the level of an “AUDIO IN” in dBA?]]> http://cycling74.com/forums/topic/how-to-calculate-the-level-of-an-audio-in-in-dba/#post-210133 Tue, 16 Aug 2011 14:02:11 +0000 alersito But if you use 40 fones you are on A-weight, isnt it?

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