Auto Feedback?

May 23, 2007 at 2:20pm

Auto Feedback?

Hi, does anyone know how I would go about making an auto-feedback system similar to the ‘feedback network’ Pluggo.

It would need to turn down a gain control slightly once a threshold level was reached, wait a set time, then gradually increase the gain again.

I imagine one could use the avg~ object to keep an eye on the level but I’m not quite sure about the rest.

Helpful thoughts much appreciated.

Thanks
Will

#32047
May 23, 2007 at 2:44pm

Hi Will,

Check out the thresh~ object, for starters.


Owen

Will Young wrote:
> Hi, does anyone know how I would go about making an auto-feedback
> system similar to the ‘feedback network’ Pluggo.
>
> It would need to turn down a gain control slightly once a threshold
> level was reached, wait a set time, then gradually increase the gain
> again.
>
> I imagine one could use the avg~ object to keep an eye on the level
> but I’m not quite sure about the rest.
>
> Helpful thoughts much appreciated.
>
> Thanks Will _______________________________________________ maxmsp
>

#104837
May 23, 2007 at 6:16pm

Sounds like a compressor with a negative knee. Lots of ways to build
this; here’s a simple one. I’ve found that omx.comp~ is also effective
for matrix style feedbacks.

Peter McCulloch

max v2;
#N vpatcher 10 59 718 759;
#P window setfont “Sans Serif” 12.;
#P flonum 341 98 35 12 0 0 0 3 0 0 0 221 221 221 222 222 222 0 0 0;
#P flonum 288 98 35 12 0 0 0 3 0 0 0 221 221 221 222 222 222 0 0 0;
#P user scope~ 188 403 318 533 256 3 128 -60. 0. 0 0. 0 0. 102 255 51
135 135 135 0;
#P user ezdac~ 43 634 87 667 0;
#P user gain~ 57 488 24 100 158 0 1.071519 7.94321 10.;
#P comment 389 160 153 196620 turn down gain (dB);
#P comment 249 311 129 196620 base amplitude (dB);
#P flonum 348 159 35 12 0 0 0 3 0 0 0 221 221 221 222 222 222 0 0 0;
#P window linecount 3;
#P comment 303 253 322 196620 < --- you could use change~ and clip~ 0.
1. if you only wanted it when it went high , rather than continuing on
while the signal is above the threshold;
#P window linecount 1;
#P newex 119 215 116 196620 thresh~ -20. -10.;
#P newex 57 90 27 196620 +~;
#P newex 57 52 27 196620 IO;
#P newex 119 392 52 196620 dbtoa~;
#P newex 119 355 166 196620 rampsmooth~ 800 11025;
#P newex 190 306 51 196620 sig~ 0.;
#P newex 119 305 46 196620 *~ -6.;
#P newex 57 451 27 196620 *~;
#P newex 119 177 52 196620 atodb~;
#P newex 119 133 130 196620 average~ 2000 rms;
#P comment 299 360 262 196620 fast attack of negative gain , slow
release;
#P connect 15 0 16 0;
#P connect 8 0 9 0;
#P connect 9 0 3 0;
#P connect 3 0 15 0;
#P connect 8 1 9 1;
#P connect 7 0 3 1;
#P connect 15 0 16 1;
#P connect 9 0 1 0;
#P connect 1 0 2 0;
#P connect 2 0 10 0;
#P connect 10 0 4 0;
#P connect 4 0 6 0;
#P connect 5 0 6 0;
#P connect 6 0 7 0;
#P connect 12 0 4 1;
#P connect 18 0 10 1;
#P connect 6 0 17 0;
#P connect 19 0 10 2;
#P pop;

On May 23, 2007, at 10:20 AM, Will Young wrote:

>
> Hi, does anyone know how I would go about making an auto-feedback
> system similar to the ‘feedback network’ Pluggo.
>
> It would need to turn down a gain control slightly once a threshold
> level was reached, wait a set time, then gradually increase the gain
> again.
>
> I imagine one could use the avg~ object to keep an eye on the level
> but I’m not quite sure about the rest.
>
> Helpful thoughts much appreciated.
>
> Thanks
> Will
>
>
http://www.petermcculloch.com

#104838
May 24, 2007 at 1:00am

a simple feedback loop would be this:

make a tapping delay with feedback, put the feedback
value on 0.999998, then put a limiter in the feedback path.

#104839

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