I've been happy with limiter_1176_R4_mono, but I'll now compare it to limiter_basic_mono, by offering both with a checkbox to choose, and listen for the difference (see attached test program). My limiter needs are merely to turn hard-clipping into soft-clipping for voice and tonal instruments.
I believe the "limiter slope" is the compression ratio to use above threshold (4 in the case of limiter_1176_R4_mono). On Sat, May 23, 2020 at 3:57 AM Dario Sanfilippo <[email protected]> wrote: > > Hi, Julius. I understand. > > See this: > https://github.com/grame-cncm/faustlibraries/pull/37/commits/8f1bd1ba78ff4919637a9bfd9ec635225cfb4ba5 > . > > That's a basic lookahead limiter based on this post: > http://iem.at/~zmoelnig/publications/limiter/. > > This algorithm is even simpler: it just calculates the amplitude profile > using a peak-holder and it smooths out attack and release using, > respectively, a one-pole lowpass and a peak envelope. Those filters are > based on the e^(-2pi) time constant (Chamberlin's design for 1pole > filters). This time constant works in this case as the input delay is set > by the attack of the system, so the amplitude profile to calculate the > scaling factor roughly reaches its maximum after the attack time. The > release time might be changed with some other constant, if more appropriate. > > Personally, I'm satisfied with it but I also designed it for my specific > case, that is, stability in self-oscillating systems. I needed a cheap > solution with low distortion; I'm not sure if this works well for most > applications. People are invited to test and comment. > > I had a look at Zölzer's limiter, pp 231 and 232, but I don't quite > understand what "the slope of the limiter" is. What do you think? He also > doesn't mention a specific delay for the input path but I'd assume that it > is the same as the attack time. > > Dario > > > On Sat, 23 May 2020 at 01:38, Julius Smith <[email protected]> wrote: > >> Hi Dario, >> >> Yes the current limiter is simply a compressor, using the usual (causal) >> amplitude follower, that applies a ratio of 4 starting halfway up (-6 dB). >> Please feel free to make us a new one that is nicer! >> >> Julius >> >> On Fri, May 22, 2020 at 11:19 AM Dario Sanfilippo < >> [email protected]> wrote: >> >>> Hello, list. >>> >>> Am I missing something with co.limiter_1176_R4_mono? I see that there >>> is no lookahead mechanism inside and, if I test it with a song at +60dB, >>> the output of the limiter is rather consistently at about 25 dB. >>> >>> Best, >>> Dario >>> _______________________________________________ >>> Faudiostream-users mailing list >>> [email protected] >>> https://lists.sourceforge.net/lists/listinfo/faudiostream-users >>> >> -- >> "Anybody who knows all about nothing knows everything" -- Leonard Susskind >> > -- "Anybody who knows all about nothing knows everything" -- Leonard Susskind
limit.dsp
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limiter_basic_mono.dsp
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