[PD] limiter questions

[Derek Holzer]

Hi Mirko,

1) Is there any reason not to use [limiter~] (i.e. to stay Vanilla)?

2) To avoid clicks, look at:

[num\
|
[pack 0 50]
|
[line~]

where 50 can be replaced with the interpolation time you choose to avoid 
discontinuities. Output of [line~] can go to right inlet of [*~]. Using 
discreet messages to manipulate an audio signal (as you have done at the 
final [*~] in your patch) will certainly give clicks.

Details on using [line~] here:

http://en.flossmanuals.net/PureData/Amplifier

3) [env~] gives "RMS amplitude which (for a sinusoid) is about 3 dB 
below peak-to-peak amplitude" (from the [env~] help patch).  For a 
limiter you are definitely interested in the peaks and not the average!!!!

4) For something like a limiter, you might want something which does 
everything in the audio domain rather than switching between audio and 
messages through signal analysis (for the reason I wrote 
above...discrete messages give clicks). Again, [limiter~] would be the 
best choice here.

best!
D.

Mirko Maier wrote:
> hi list,
> 
> here's a limiter patch but it doesn't work.
> 
> i can calculate a limitation for decibels, but how can i adjust it to the original signal? and is it possible to avoid any click? 
> 
> thanx for hints. 
> mirko
> 
> #N canvas 603 162 1007 794 12;
> #X floatatom 426 284 5 0 0 0 - - -;
> #X obj 174 585 *~;
> #X floatatom 375 230 5 0 0 0 - - -;
> #X obj 375 196 env~ 64;
> #X obj 174 140 *~;
> #X obj 173 38 osc~ 440;
> #X obj 237 96 pipe 10;
> #X msg 244 58 4;
> #X msg 278 58 0.5;
> #X obj 276 21 bng 15 250 50 0 empty empty empty 0 -6 0 8 -262144 -1
> -1;
> #X floatatom 402 87 5 0 0 0 - - -;
> #X floatatom 426 345 5 0 0 0 - - -;
> #X floatatom 321 404 5 0 0 0 - - -;
> #X obj 298 374 *;
> #X floatatom 349 457 5 0 0 0 - - -;
> #X obj 301 638 env~ 64;
> #X obj 175 261 z~ 64;
> #X obj 375 255 moses 90;
> #X obj 426 312 expr 90/$f1;
> #X text 395 387 1st question:;
> #X text 299 21 <- 2nd question: is it possible to really get no click?
> ;
> #X text 390 414 it's no problem to limit the number stream (limit is
> 90db);
> #X text 420 453 but it should be the same here! how convert?;
> #X text 66 38 test signal;
> #X text 454 86 any amplification \, e.g. 2;
> #X obj 173 732 dac~;
> #X connect 0 0 18 0;
> #X connect 1 0 15 0;
> #X connect 1 0 25 0;
> #X connect 1 0 25 1;
> #X connect 2 0 13 0;
> #X connect 2 0 17 0;
> #X connect 3 0 2 0;
> #X connect 4 0 3 0;
> #X connect 4 0 16 0;
> #X connect 5 0 4 0;
> #X connect 6 0 4 1;
> #X connect 7 0 4 1;
> #X connect 8 0 6 0;
> #X connect 9 0 7 0;
> #X connect 9 0 8 0;
> #X connect 10 0 4 1;
> #X connect 11 0 13 1;
> #X connect 11 0 1 1;
> #X connect 13 0 12 0;
> #X connect 15 0 14 0;
> #X connect 16 0 1 0;
> #X connect 17 1 0 0;
> #X connect 18 0 11 0;
> 

-- 
::: derek holzer ::: http://blog.myspace.com/macumbista ::: 
http://www.vimeo.com/macumbista :::
---Oblique Strategy # 117:
"Make it more sensual"