Posted: Thu Apr 29, 2004 8:22 am
This is sort of a cross post from the device/module wishlist, but I just found out after a while of experimenting, that there is no way physmod is possible on Mod.
Just as a memory refresher, the Karplus-Strong string modeling method uses several delays in a feedback loop (represents the string), and sends it an impulse (pluck, etc.) to cause sound. The delay time controls how long the string is, and inturn controls pitch.
So this is basically what all the "plucked string" type physmod does. I decided to try to implement it using the mod delay module in ModIII and try to make me one.
Problems:
CW mod delay module has built in lowpass and so the signal altered during the delay. (thanx to j9k for informing me about this) For Karplus-Strong, you need delays that simply delay what you feed it, and throws it back 100% unaltered.
Delay time controls pitch, and theoretically, modulating the delay time of mod delay can control pitch. It works, to an extent, but there is no way to control pitch using the keyboard, as in, I can't convert MIDI note numbers to proper delay time format. Ideally, I would convert like this: notenumber->hertz->time it takes for 1 cycle in millisecs. In Mod, there are no objects that can do Note number->hertz conversion.
With the experiment I did, I got some sound... using a bunch of improper workarounds, (out went the concept of scientific accuracy) and ended up with a string that could be plucked by keystroke, pitch controled with a const val slider (range was only about 4 semitones). The plucked sound was okay, but the decay would morph into a sin wave at high pitches, and morph into a squarewave at low pitches. If anyone's interested, I'll post the patch.
Conclusion? The result I got sounds nothing like a plucked string. It's scientifically totally inaccurate, and the pitch can't be effectively controlled. BUT, the resulting sound is really strange and almost magical. I think I may even tweak it so that it's playable as an instrument of its own kind.
<font size=-1>[ This Message was edited by: kensuguro on 2004-04-29 09:23 ]</font>
Just as a memory refresher, the Karplus-Strong string modeling method uses several delays in a feedback loop (represents the string), and sends it an impulse (pluck, etc.) to cause sound. The delay time controls how long the string is, and inturn controls pitch.
So this is basically what all the "plucked string" type physmod does. I decided to try to implement it using the mod delay module in ModIII and try to make me one.
Problems:
CW mod delay module has built in lowpass and so the signal altered during the delay. (thanx to j9k for informing me about this) For Karplus-Strong, you need delays that simply delay what you feed it, and throws it back 100% unaltered.
Delay time controls pitch, and theoretically, modulating the delay time of mod delay can control pitch. It works, to an extent, but there is no way to control pitch using the keyboard, as in, I can't convert MIDI note numbers to proper delay time format. Ideally, I would convert like this: notenumber->hertz->time it takes for 1 cycle in millisecs. In Mod, there are no objects that can do Note number->hertz conversion.
With the experiment I did, I got some sound... using a bunch of improper workarounds, (out went the concept of scientific accuracy) and ended up with a string that could be plucked by keystroke, pitch controled with a const val slider (range was only about 4 semitones). The plucked sound was okay, but the decay would morph into a sin wave at high pitches, and morph into a squarewave at low pitches. If anyone's interested, I'll post the patch.
Conclusion? The result I got sounds nothing like a plucked string. It's scientifically totally inaccurate, and the pitch can't be effectively controlled. BUT, the resulting sound is really strange and almost magical. I think I may even tweak it so that it's playable as an instrument of its own kind.
<font size=-1>[ This Message was edited by: kensuguro on 2004-04-29 09:23 ]</font>
