Attached patch illustrates how [iemlib/hp1~] is calculated. This gives a perfect hipass, [hip~] could (or should) be done the same way I guess.
Katja On Fri, Jan 30, 2015 at 6:21 AM, Alexandre Torres Porres <[email protected]> wrote: >> This message of mine was intended to be a bug report > > I see, but my point is that it's not much of a "bug", so if you want to see > how these filters work more deeply, you may check my stuff. > > You can see how I made versions of the filters as [fexpr~] or [biquad~] and > the raw filters. I made [vcf~] out of [cpole~], for example. And you can > check the plot of magnitude/phase. > >> I know (and enjoy very much) yours >> Computer Music With Examples In Pd. > > Thanks. That got old though... I translated from portuguese what I had for a > workshop at the last pd convention in 2011, but it's mostly FFT. My current > portuguese version is way bigger, up to 250 examples in the next release I'm > planning for next month. These patches I'm sharing is from my newest > releases. > >> Probably it would be better then to warn users >> about this limit of ~12 kHz in the help-files then. > > Yeah, it'd be good to point out a bit of its characteristics. I learned a > lot by checking on my own. > > I could realize how [bp~] is quite similar to the resonant lowpass from > [lores~] for example. Its just a matter of setting up the gain. If you set > [bp~]'s Q to 1, you'll also see how it behaves much like a lowpass filter > like [lop~]. The [vcf~] filter has similar characteristics. > > cheers > > 2015-01-30 0:19 GMT-02:00 Gilberto Agostinho > <[email protected]>: > >> Hi Alexandre, thanks for your reply. >> >> On 30/01/15 02:39, Alexandre Torres Porres wrote: >> >> it's how the filters were designed, they're not perfect throughout the >> spectrum >> >> >> Probably it would be better then to warn users about this limit of ~12 kHz >> in the help-files then. >> >> you'll need to use/build other filters for that purpose of working with >> that higher portion of the spectrum (in which I can hardly still hear, by >> the way)/ >> >> >> Hmm, I can clearly hear the difference between feeding a high frequency to >> [vcf~] and to [bp~] using a large enough Q (~100 for instance). With that Q, >> try sweeping from 12kHz until 14kHz in both filters, and you'll hear that >> [vcf~] behaves as expected, while [bp~] does not change the frequency but >> only affects the amplitude of the output for some reason. >> >> a few of patches of mine that describe the behaviour of vanilla and some >> extended filters >> >> >> Thanks a lot for the patches, but I am actually aware of [vcf~] and >> [biquad~]. This message of mine was intended to be a bug report rather than >> a cry for help as I have no particular problem with filters needing a >> solution right now. But in any case I will check your patches, as I know >> (and enjoy very much) yours Computer Music With Examples In Pd. >> >> Take care, >> Gilberto Agostinho > > > > _______________________________________________ > [email protected] mailing list > UNSUBSCRIBE and account-management -> > http://lists.puredata.info/listinfo/pd-list >
#N canvas 15 132 643 583 10; #X obj 128 67 osc~ 440; #X floatatom 128 41 5 0 0 0 - - -; #X msg 100 12 100; #X msg 128 12 1000; #X msg 166 12 10000; #X msg 211 12 15000; #X obj 61 505 env~ 8192; #X floatatom 61 535 5 0 0 0 - - -; #X msg 530 211 \; pd dsp 1; #X msg 530 250 \; pd dsp 0; #X obj 480 101 hip~; #X obj 481 499 env~ 8192; #X floatatom 481 532 5 0 0 0 - - -; #X obj 49 97 cnv 15 320 400 empty empty empty 20 12 0 14 -233017 -66577 0; #X obj 61 148 rzero~ 1; #X floatatom 231 446 8 0 0 0 - - -; #X floatatom 128 445 8 0 0 0 - - -; #X text 125 459 normalisation; #X obj 128 302 cos; #X obj 128 274 t f f; #X obj 155 302 sin; #X obj 128 331 /; #X obj 231 392 - 1; #X obj 258 392 + 1; #X obj 231 365 t f f; #X obj 231 423 /; #X obj 155 393 + 1; #X obj 128 365 t f f; #X obj 128 417 /; #X floatatom 317 348 5 0 0 0 - - -; #X obj 128 200 atan; #X msg 128 173 1; #X obj 128 250 /; #X obj 128 148 t b f; #X obj 128 224 * 4; #X obj 61 434 *~ 0; #X floatatom 175 241 5 0 0 0 - - -; #X text 211 238 pi; #X text 157 220 normalized frequency / 2 (radians); #X obj 60 465 rpole~; #X text 196 148 adapted from [iemlib/hp1~]; #X text 228 462 feedback coefficient; #N canvas 334 409 336 219 freqtosamps 0; #X obj 24 27 inlet; #X obj 24 172 outlet; #X obj 24 90 samplerate~; #X obj 24 122 /; #X obj 24 59 t b f; #X floatatom 64 139 5 0 0 0 - - -; #X connect 0 0 4 0; #X connect 2 0 3 0; #X connect 3 0 1 0; #X connect 3 0 5 0; #X connect 4 0 2 0; #X connect 4 1 3 1; #X restore 128 114 pd freqtosamps; #X text 452 65 Katja Vetter Jan. 2015; #X text 267 12 This patch compares [hip~] with the hipass filter recipe in [iemlib/hp1~]. The iemlib recipe gives -3 dB consistently at cutoff frequency \, whereas [hip~] in Pd vanilla/extended does not \, at the moment.; #X connect 0 0 10 0; #X connect 0 0 14 0; #X connect 1 0 0 0; #X connect 1 0 10 1; #X connect 1 0 42 0; #X connect 2 0 1 0; #X connect 3 0 1 0; #X connect 4 0 1 0; #X connect 5 0 1 0; #X connect 6 0 7 0; #X connect 10 0 11 0; #X connect 11 0 12 0; #X connect 14 0 35 0; #X connect 18 0 21 0; #X connect 19 0 18 0; #X connect 19 1 20 0; #X connect 20 0 21 1; #X connect 21 0 24 0; #X connect 21 0 27 0; #X connect 21 0 29 0; #X connect 22 0 25 0; #X connect 23 0 25 1; #X connect 24 0 22 0; #X connect 24 1 23 0; #X connect 25 0 15 0; #X connect 25 0 39 1; #X connect 26 0 28 1; #X connect 27 0 28 0; #X connect 27 1 26 0; #X connect 28 0 16 0; #X connect 28 0 35 1; #X connect 30 0 34 0; #X connect 31 0 30 0; #X connect 32 0 19 0; #X connect 33 0 31 0; #X connect 33 1 32 1; #X connect 34 0 32 0; #X connect 34 0 36 0; #X connect 35 0 39 0; #X connect 39 0 6 0; #X connect 42 0 33 0;
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