How is sympathetic resonance made ?

[Mr_-G-]

Just found the following article about "Kontakt PMI Pianos" and sympathetic resonance : http://www.postpiano.com/products/K2.htm
Simply :
1- have an algorithm to decide what sample to trigger, according to what is played.
2- process and trigger them !

Wouldn't that reduce polyphony a bit? Maybe it does but we do not notice it?

[Frantz]

As polyphony is a decision that depends on available processing power ... you see the picture, more power, same polyphony for played notes, some available for other resonance things. That applies to modeled pianos too.

[maxpiano]

Just found the following article about "Kontakt PMI Pianos" and sympathetic resonance : http://www.postpiano.com/products/K2.htm
Simply :
1- have an algorithm to decide what sample to trigger, according to what is played.
2- process and trigger them !

That could be : "trigger some E 330 Hz when A 440 Hz is played, because they share an overtone of 1320 Hz (3rd harmonic of A and 4th harmonic of E)".
Just guessing
Frantz.

that's in line with my statement, I also own the Galaxy Vintage D VSTi piano and I am pretty sure that also in that case the above technique is applied.

Of course the quality of samples and of the algorithm (point 1 above) can make quite a difference and Nord has done a great job in compressing the sample data while still providing a good final result (thanks to their algorithms).

About polyphony, if the DSP is programmed in a way that the result of sympathetic resonance calculation for a given key is added to the same key "base waveform" and has enough processing power to do it without increasing latency, then it can still use 1 voice per key (including its associated sympathetic resonances)

PS: an in depth analysis of Nord Piano was made on Pianoforum DPBSD project Link to the thread page with NP test