Forums > MaxMSP

audio sensor box

September 21, 2006 | 10:51 am

hi there : ) i’m trying to use fiddle~ in order to obtain the audio signal
coming from an audio sensor box in http://www.antfood.com can anyone give me a hint
about a patch to do this? thank you


September 21, 2006 | 12:29 pm


September 21, 2006 | 1:29 pm

I think the URL is here:

http://www.antfood.com/ads/audiosensing.htm

The box sends out an audio signal ranging from 10khz to 20 khz, so Fiddle would be an appropriate object to use.


September 21, 2006 | 1:56 pm

On 21 Sep 2006, at 14:29, David Whitely wrote:

>
> I think the URL is here:
>
> http://www.antfood.com/ads/audiosensing.htm
>
> The box sends out an audio signal ranging from 10khz to 20 khz, so
> Fiddle would be an appropriate object to use.

Except that he is using fixed frequency oscillators, which are
amplitude modulated by the data. fiddle~ is for frwequency tracking,
which is not relelvant here. He suggests using fft; you might also
try narrow band filters tuned to each of the frequencies.

Best

L

Lawrence Casserley – lawrence@lcasserley.co.uk
Lawrence Electronic Operations – http://www.lcasserley.co.uk
Colourscape Music Festivals – http://www.colourscape.org.uk


September 21, 2006 | 2:03 pm

Maybe you can write to the creator of the antbox for an example max patch?

dw


September 21, 2006 | 2:27 pm

thanks :) i wrote him but i got no answer…i’ll keep on trying…

2006/9/21, David Whitely :
>
>
> Maybe you can write to the creator of the antbox for an example max patch?
>
> dw
>


September 21, 2006 | 5:11 pm


September 22, 2006 | 4:39 pm


September 22, 2006 | 4:59 pm


September 22, 2006 | 6:37 pm

Hello,
Here is a patch that theoretically does something like what you will
need to do. The rect~ objects are merely there as a model of the square
waves that you will be receiving from your audio interface. The FFT
portion passes only a specific frequency bin of amplitude data. From
this, you can use abs~ and rampsmooth~ to follow the amplitude of the
signal. Remember that you will most likely need to tune your
oscillators so that they fit nicely into different frequency bins.
Looking at the schematic, it appears that the left and right channel use
the same oscillators.

Seems like a pretty cool circuit. I may try building it myself just to
see if it works as advertised.

Cheers,
Andrew B.

#P window setfont "Sans Serif" 9.;
#P window linecount 1;
#P newex 41 231 27 196617 *~;
#P newex 58 207 27 196617 ==~;
#P newex 10 232 27 196617 *~;
#P newex 10 252 61 196617 ifft~ 32 32;
#P newex 10 186 58 196617 fft~ 32 32;
#P flonum 183 127 35 9 0 0 0 3 0 0 0 221 221 221 222 222 222 0 0 0;
#P newex 155 126 27 196617 *~;
#P flonum 112 127 35 9 0 0 0 3 0 0 0 221 221 221 222 222 222 0 0 0;
#P newex 84 126 27 196617 *~;
#P newex 145 308 113 196617 rampsmooth~ 20 1000;
#P flonum 41 127 35 9 0 0 0 3 0 0 0 221 221 221 222 222 222 0 0 0;
#P newex 10 127 27 196617 *~;
#P message 107 185 20 196617 12;
#P user scope~ 146 329 276 459 64 3 64 -1. 1. 0 0. 0 0. 102 255 51 135
135 135 0;
#P newex 145 288 31 196617 abs~;
#P message 129 185 20 196617 14;
#P message 75 185 20 196617 10;
#P user ezdac~ 279 329 323 362 0;
#P user scope~ 10 330 140 460 32 3 64 -1. 1. 0 0. 0 0. 102 255 51 135
135 135 0;
#P newex 155 99 68 196617 rect~ 19000;
#P newex 83 99 68 196617 rect~ 16500;
#P newex 10 99 71 196617 rect~ 14000.;
#P connect 19 0 18 0;
#P connect 18 0 3 0;
#P fasten 18 0 7 0 15 277 150 277;
#P connect 2 0 15 0;
#P connect 1 0 13 0;
#P connect 0 0 10 0;
#P connect 20 0 19 1;
#P connect 20 0 21 1;
#P connect 21 0 18 1;
#P connect 17 1 21 0;
#P connect 6 0 20 1;
#P connect 9 0 20 1;
#P connect 5 0 20 1;
#P connect 17 2 20 0;
#P connect 17 0 19 0;
#P fasten 15 0 17 0 160 171 15 171;
#P fasten 13 0 17 0 89 162 15 162;
#P connect 10 0 17 0;
#P connect 16 0 15 1;
#P connect 14 0 13 1;
#P connect 7 0 12 0;
#P connect 12 0 8 0;
#P connect 11 0 10 1;
#P window clipboard copycount 22;


September 23, 2006 | 11:12 am


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