[sdiy] Filter slopes

[Tom Wiltshire]

Ok, I don’t know anything about “coupled resonators”. What would I look up to find out more (aside from that obvious term ), and how would I implement such a thing for analogue audio? Making “resonators” is easy enough. How do I “couple” them?

I’m looking for a practical implementation with details of how that was arrived at, rather than a highly abstract splurge of math that I won't understand and which could probably be explained in words of two syllables or less if anyone took the time to bother.

Thanks,
Tom

==================
       Electric Druid
Synth & Stompbox DIY
==================

> On 11 Jun 2018, at 20:50, ASSI <Stromeko at nexgo.de> wrote:
> 
> On Monday, June 11, 2018 7:43:22 AM CEST Elain Klopke wrote:
>> I was reading an article about the spectral content of various instruments
>> (woodwinds and strings) and while they didn't have any circuits, there were
>> some tables showing cutoff frequencies and high and low slopes. Several of
>> the pictures looked like bandpass filter responses with different slopes on
>> each side. How would I go about doing that? Is the slope determined by the
>> gain of the op amp in an active filter? If it's that easy, would it be a
>> highpass filter followed by a lowpass filter each with their own gain
>> settings?
> 
> Both woodwinds and string instruments (among others) can be modeled with 
> coupled resonators.  The characteristic timbre of each is related to the modes 
> of these resonators and the transfer of energy between them.  The slopes of 
> the bandpass skirts depend on both the quality factor of the resonator and the 
> coupling strength to other resonators or resonator modes.  Generally speaking, 
> losing energy (e.g. into another mode) is a reduction in Q and hence shows up 
> as a flattening of the slope.  If you just want to approximate the magnitude 
> response, a filter bank with a high enough number of filter bands is as good 
> as any other method and relatively easy to implement, it just uses many de-
> coupled resonators instead of few(er) coupled ones.
> 
> 
> Regards,
> Achim.
> -- 
> +<[Q+ Matrix-12 WAVE#46+305 Neuron microQkb Andromeda XTk Blofeld]>+
> 
> Wavetables for the Terratec KOMPLEXER:
> http://Synth.Stromeko.net/Downloads.html#KomplexerWaves
> 
> 
> 
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