rs-met

LOSER · Post by **LOSER** » Sat Mar 22, 2008 10:18 am

Hey, just dropped in to say that your plug-ins are really great, expecially the Func Shaper and the 3-Way Crossover (wish I had the brains to do more complexe/higher order filters ... well one day). Anyway great stuff, take care, bye.

Music Engineer · Post by **Music Engineer** » Sat Mar 22, 2008 2:01 pm

much thanks. as for filter design: i'd recommend to start with thinking about filters in terms of poles and zeros and then ask yourself where to place them (in the s- or z-plane) in order to achieve a desired frequency response. maybe the easiest standard result for closed form equations for the pole/zero locations is the (analog, s-plane) butterworth filter:

http://ccrma.stanford.edu/~jos/filters/ ... Zeros.html

once you have grokked butterworth, the rest is straightforward (although it becomes quite involved when you turn to the elliptics). linkwitz/riley is just two identical butterworths in series.

LOSER · Post by **LOSER** » Sun Mar 23, 2008 7:30 pm

Robin from www.rs-met.com wrote:much thanks. as for filter design: i'd recommend to start with thinking about filters in terms of poles and zeros and then ask yourself where to place them (in the s- or z-plane) in order to achieve a desired frequency response. maybe the easiest standard result for closed form equations for the pole/zero locations is the (analog, s-plane) butterworth filter:

http://ccrma.stanford.edu/~jos/filters/ ... Zeros.html

once you have grokked butterworth, the rest is straightforward (although it becomes quite involved when you turn to the elliptics). linkwitz/riley is just two identical butterworths in series.

Yeah, I know well at least some parts anyway. I just seem to have no idea about the whole s-plane and transforms etc.. I know the complex plane, complex numbers, advanced math, what a filter is and what it does, and all that stuff, though it seems I'm lacking at bringing both together, but I must admit I haven't really tried very hard yet. So yeah .. one day

.

Music Engineer · Post by **Music Engineer** » Sun Mar 23, 2008 8:51 pm

LOSER wrote:Yeah, I know well at least some parts anyway. I just seem to have no idea about the whole s-plane and transforms etc..
I know the complex plane, complex numbers, advanced math, what a filter is and what it does, and all that stuff, though it seems I'm lacking at bringing both together, but I must admit I haven't really tried very hard yet. So yeah .. one day .

i wish you success. think of the laplace transform as a natural generalization of the complex fourier-transform by just replacing the exp(j*omega) term (a rotating phasor) with a general complex number 's' (a spiraling phasor). for further studies of filter design (probably not to begin with), i recommend orfanidis' work:

http://www.ece.rutgers.edu/~orfanidi/ece521/notes.pdf

...postpone reading of that, until you feel comfortable with the butterworth design procedure. and don't give up early when something seems too math-heavy - filter design is not trivial but not black magic either.

jupiter8 · Post by **jupiter8** » Sun Mar 23, 2008 8:53 pm

Robin from www.rs-met.com wrote:filter design is not trivial but not black magic either.

Yes it is.

Music Engineer · Post by **Music Engineer** » Sun Mar 23, 2008 9:01 pm

is what? black magic? trivial? non-trivial?

jupiter8 · Post by **jupiter8** » Sun Mar 23, 2008 9:04 pm

Robin from www.rs-met.com wrote:is what? black magic? trivial? non-trivial?

Black magic.

I know how all other stuff in a synth works and have several ideas and know how to implement them but when it comes to filters i'm just blank. I have no idea what to look for and how to achieve it.

Seriously a friend of mine is getting into DSP and knows about Z-Transforms and whathaveyous and we frequently discuss DSP stuff but when he asks about filters i just shrug my shoulders and reply: It's black magic man. (No joke i actually said that. That's why it's funny you said it's not).

Music Engineer · Post by **Music Engineer** » Sun Mar 23, 2008 9:27 pm

jupiter8 wrote: we frequently discuss DSP stuff but when he asks about filters i just shrug my shoulders and reply: It's black magic man. (No joke i actually said that. That's why it's funny you said it's not).

aha, hihi...yes...the *excellent* julius smith stuff (especially his (free) online ebook on filters) is a great read to de-mystify these things...if you really want to

jupiter8 · Post by **jupiter8** » Sun Mar 23, 2008 9:33 pm

I've read plenty filter theory and i DO grasp the theory behind them (kinda) however what i have a problem with is: What is a good filter ? What do you look for ? For an oscillator i have tons of ideas and know what to do but a good filter ?

For example i'm convinced i could do a decent emulation of an analog oscillator should i want to but a filter ? I would'nt even know where to start.

The only thing i've done filterwise is i read a paper by the EMU guy (Dave Rossum) about distorsion in the feedback path and that was easily done and very interesting but that's about it.

Music Engineer · Post by **Music Engineer** » Sun Mar 23, 2008 9:52 pm

when it comes to musical applications such as filters in synthesizers, a whole different box is opened. all that (linear) filter theory is well, good and helpful but actually not that relevant. you don't see chebyshev filters in a subtractive synth, for example. instead you see 'moog' filters. the design goals are completely different for synthesizer filters than for 'classical' dsp filters. what makes a filter sound good? mmhh, the answer probably cannot really given once for all because its so subjective. i would say, an important aspect is how the resonace behaves when one sweeps the cutoff frequency.

jupiter8 · Post by **jupiter8** » Sun Mar 23, 2008 9:57 pm

That's what i said. Black magic.
You really should'nt mess with the forces of evil.Could be dangerous.

tongsong · Post by **tongsong** » Sat Aug 08, 2009 6:38 pm

just want to say thanks, Your plugins r GREAT!, good looking good soundeasy Q is my go to EQ now!!!

Music Engineer · Post by **Music Engineer** » Sun Aug 09, 2009 11:19 pm

tongsong wrote:just want to say thanks, Your plugins r GREAT!, good looking good soundeasy Q is my go to EQ now!!!

you're welcome. glad to hear that EasyQ lives up to its designation as a go-to EQ

solomute · Post by **solomute** » Mon Oct 09, 2017 7:11 pm

These plugins are blocked by corp mechanisms in DP and also in jbridge at least jbridge does not help to load them into DP. You have to use metaplugin vst to load Robin's plugins. And all because of good maths apparatus inside the plugins. Robin is like Robin Good who wanted to give us true quality and education. I have noticed also that DP blocks airwindows plugins. Again solved by metaplugin but ... Robin, what do you think about airwindows plugins? Are they fake placebo and a fooling trick or another antiglobalistic project?

solomute · Post by **solomute** » Tue Oct 10, 2017 12:12 am

The only way to load them is via jbridge + ddmf metaplugin.

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