Oh interest challenge of the definition of resonance. The typical textbook diagram shows a little local bump at some frequency in a bode diagram, but if you consider dc the resonant frequency, then the only way to show a bump is by being higher than all the other frequencies (i.e. monotonically decreasing).
Hmm, I wonder. One common definition of resonance bandwidth is also the "3dB" point. But I guess resonating at dc is probably not a common use case. Stefan On Sun, Jul 22, 2018, 18:11 robert bristow-johnson <[email protected]> wrote: > > I've been wondering about the connection that resonance and filter orders > at least 2. That's 2 delays (and feedback). > > But if you're limiting the resonant frequencies to DC and Nyquist, then > with a one-sample delay digital filter, you can have something like > "resonance". > > Even if the single delay is two samples long (but no tap in the middle), > that allows only DC, Nyquist, or half-Nyquist as tunable frequencies. > > So just sayin, in another sense of the word, that "resonance" can be had > with a single *long* delay and one feedback path or with two arbitrarily > short delays and two feedback paths. > > > > -- > r b-j [email protected] > > "Imagination is more important than knowledge." > > > > > > -------- Original message -------- > From: Stefan Sullivan <[email protected]> > Date: 7/22/2018 2:20 PM (GMT-08:00) > To: A discussion list for music-related DSP <[email protected]> > > Subject: Re: [music-dsp] What is resonance? > > Yes. The term helmholz resonator should be a hint ;) Basically when a > sounds gets added to itself after a delay you end up adding energy to the > frequency that corresponds to that delay amount. For very long echos we > don't hear it as a resonance, but for shorter delays it will boost higher > and higher frequencies into the audible range. > > Stefan > > On Sun, Jul 22, 2018, 08:10 <[email protected]> wrote: > >> Hello all >> >> Is "feedback with delay" really resonance? I recognize many people >> describe the effects of "room resonanes this way", but to my understanding >> these are no resonances in the basic meaning but reflections. A resonance >> is a self standing oscillating system like a guitar string or an air mass >> in a Helmholtz resonator. >> >> Rolf >> >> *Gesendet:* Samstag, 21. Juli 2018 um 04:33 Uhr >> *Von:* "Andrew Simper" <[email protected]> >> *An:* "A discussion list for music-related DSP" < >> [email protected]> >> *Cc:* [email protected], [email protected], >> [email protected] >> *Betreff:* Re: [music-dsp] What is resonance? >> Resonance is just delay with feedback. Resonance occurs when you delay a >> signal and then feed it back with some gain to the input of the delay "in >> phase" >> >> _______________________________________________ >> dupswapdrop: music-dsp mailing list >> [email protected] >> https://lists.columbia.edu/mailman/listinfo/music-dsp > > _______________________________________________ > dupswapdrop: music-dsp mailing list > [email protected] > https://lists.columbia.edu/mailman/listinfo/music-dsp
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