## SMooth cutoff control

Dec 27, 2007 at 4:04pm

# SMooth cutoff control

Hi all trying to create a knob to change my cutoff frequency on my Biquad filter graph. I want to then control it by midi but im having problems getting the knob to smoothly rotate this is because the range of the knob is 127 for midi.

Ive tried dividing the output by 127.0 and then multiplying by 22000.0 and putting the output into the cutoff input, but this isn’t any good as there are big steps in frequency when turning from low frequencies, it is fine as i reach the high frequencies and this is because of the maths technique i used, but i can’t figure out another method.

I am very new to MSP so any help would be well appreciated. Thanks.

#35136
Dec 27, 2007 at 6:23pm

Have a look at [scale], perhaps in conjunction with [line] or [line~].

On Dec 27, 2007, at 11:04 AM, Stuart Spencer wrote:

>
> Hi all trying to create a knob to change my cutoff frequency on my
> Biquad filter graph. I want to then control it by midi but im
> having problems getting the knob to smoothly rotate this is because
> the range of the knob is 127 for midi.
>
> Ive tried dividing the output by 127.0 and then multiplying by
> 22000.0 and putting the output into the cutoff input, but this
> isn’t any good as there are big steps in frequency when turning
> from low frequencies, it is fine as i reach the high frequencies
> and this is because of the maths technique i used, but i can’t
> figure out another method.
>
> I am very new to MSP so any help would be well appreciated. Thanks.

—-
Steven M. Miller
Professor, Contemporary Music Program
College of Santa Fe

#119373
Dec 27, 2007 at 6:44pm

>Hi all trying to create a knob to change my cutoff frequency on my
>Biquad filter graph. I want to then control it by midi but im having
>problems getting the knob to smoothly rotate this is because the
>range of the knob is 127 for midi.
>

what i do is this
you probabbly can adapt so i makes what you need

best

kasper

#P window setfont “Sans Serif” 9.;
#P window linecount 1;
#P comment 291 212 40 196617 freq;
#P flonum 301 194 82 9 0 0 0 3 0 0 0 221 221 221 222 222 222 0 0 0;
#P user hslider 462 70 18 128 128 1 0 0;
#P newex 404 104 99 196617 scale 0 127 0 1001;
#P newex 392 343 102 196617 filtercoeff~ lowpass;
#P flonum 393 250 35 9 0 0 0 3 0 0 0 221 221 221 222 222 222 0 0 0;
#P message 392 298 43 196617 \$1 222;
#P newex 392 319 32 196617 line~;
#P newex 392 274 31 196617 mtof;
#P newex 393 230 111 196617 scale 0 1000 15. 130.;
#P user dial 383 180 29 29 1001 1 0 0 202 270 2 1. 17 17 17 91 91 91
120 120 120 225 225 225 247 247 247 0 0 0;
#P comment 612 75 100 196617 incoming midi;
#P comment 414 191 100 196617 interface;
#P connect 10 0 9 0;
#P connect 9 0 2 0;
#P connect 4 0 11 0;
#P connect 4 0 6 0;
#P connect 7 0 4 0;
#P connect 2 0 3 0;
#P connect 3 0 7 0;
#P connect 6 0 5 0;
#P connect 5 0 8 0;
#P window clipboard copycount 13;

Kasper T. Toeplitz
noise, composition, bass, computer

http://www.sleazeArt.com

http://www.myspace.com/sleazeart

#119374
Dec 28, 2007 at 4:08pm

what do i do with code to get it go into msp, cant work it out.

thanks stu??

#119375
Dec 28, 2007 at 4:13pm

worked it out duuuuh! had msp on lock couldn’t paste god damn noobs .

#119376
Dec 28, 2007 at 4:27pm

MASSIVE thanks Kasper, learning hell of alot off you thanks.

#119377

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