
Acoustic modular sounds
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- AndreasKrebs
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Thanks! The tracks were not intended to be demos, but I'm happy if they are useful as such.en. wrote:thank you andreas for your very detailed and nice old school demos!
somewhere, in the first track mostly, it seems you are playing objects more than acoustic instruments, that is interesting anyhow
I like it to be able to use the synth as some kind of "percussive instrument" as well as a tonal one (and everything in between). The BBDs are quite helpful for this.
Andreas
The original work was:dougcl wrote:Holy cow I had no idea the finite element method (and finite differences) were being applied to sound synthesis.
"On the oscillations of musical instruments", McIntyre, Schumacher and Woodhouse, J. Acoust. Soc. Am 74(5), 1983.
This was the basis for the Yamaha VL1 Virtual Acoustic Tone Generator and other physical modeling synths. (Physical modeling originally refered to machines running physics models of instruments, not the current meaning of emulating synth circuits.) Julius Smith (Stanford CCRMA) probably still has a lot of his work up at his site.

Ian
Still deciding between 256 and 512?
After researching all this stuff, I'm still not sure which to get between the 256 and 512. It seems like most of the demos of the 256 sound a little more like Karplus Strong to me and the 512 sounds a little more like a delay. Any opinions on this? I was set on the 512 but now I'm not so sure....
- selfoscillate
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- AndreasKrebs
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When you go lower in pitch, you will sooner hear the 256's internal clock oscillator than the 512's (i.e. you will sooner need to apply a steep lowpass filter like the A-108 to its output).dykesh wrote:Does that mean the 256 cannot go as low as the 512 or is the limitation just on the higher octaves? Thanks...
Andreas
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the highest and lowest possible pitches are directly coupleddykesh wrote:Does that mean the 256 cannot go as low as the 512 or is the limitation just on the higher octaves? Thanks...
to the number of stages in a bbd. a bbd has a maximum and
a minimum delay time, limiting the frequency range on both
ends. bbd's with different size play in different octaves, to say so.
my personal impression is that the shorter bbd's give better results
than longer bbd's, when used in a karplus strong patch. the smaller
bbd's sound cleaner and less distorted. or in other words,
less "delay" and more "oscillator".
- AndreasKrebs
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I think just for KP applications, the 256 stage version of 188-1 is the best compromise in terms of usable range and simplicity. With that one the clock noise isn't normally an issue when you are trying to produce pitches above 250 Hz or so.
Just to muddy the waters though, you don't always have to lower the clock rate to the point where it is audible to get lower frequency pitches. Putting a filter in the feedback loop can change the pitch and timbre of the output quite dramatically. I had a weird kind of baritone sax thing going on the other day doing just this at a clock rate that, unfiltered, produced tones an octave higher.
It was a bastard to get it to track properly though. So ideal for microtonal free jazz.
Just to muddy the waters though, you don't always have to lower the clock rate to the point where it is audible to get lower frequency pitches. Putting a filter in the feedback loop can change the pitch and timbre of the output quite dramatically. I had a weird kind of baritone sax thing going on the other day doing just this at a clock rate that, unfiltered, produced tones an octave higher.
It was a bastard to get it to track properly though. So ideal for microtonal free jazz.
- selfoscillate
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the a188/2 uses a 3328 stages bbd, it only has an output tap for 396 stages,dykesh wrote:It looks like the 188-2 goes down to only 396? Am I looking at this correctly? I'm reading the manuals but I'm not sure what I would lose with a 188-2? Reading the description makes me think the clock noise may be a little too much??? Oh, and Andreas, I loved those songs you put up!!!
which is not the same as if it would have 396 stages in total.
the a188/2 is much noisier than f.e. the a188/1 with 256 stages, not
only regarding the clock noise, but in general.
i like the a188/2 too, but not for karplus strong stuff.
- AndreasKrebs
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The A-188-1X (128 stages only) can reach quite low regions. Here's a short sound demo:
http://www.andreaskrebs.de/assets/media/A-188-1X.mp3
Patch: A-155 Sequencer triggers an A-142 VC Decay envelope which controls an A-132-3 VCA (short decay time). VCA input is some noise from an A-117. VCA out goes into an A-188-1X BBD. The BBD frequency is controlled by the A-155 and an A-185-2 (to switch octaves - something like octaves: 1 oct down every 30 seconds).
In the feedback loop, an A-108 is inserted with bandpass out, no emphasis and manually changed filter frequency. BBD output is sent into another A-108 (filter frequency is controlled by BBD frequency CV out), the 48dB out is then sent into DAW.
Andreas
http://www.andreaskrebs.de/assets/media/A-188-1X.mp3
Patch: A-155 Sequencer triggers an A-142 VC Decay envelope which controls an A-132-3 VCA (short decay time). VCA input is some noise from an A-117. VCA out goes into an A-188-1X BBD. The BBD frequency is controlled by the A-155 and an A-185-2 (to switch octaves - something like octaves: 1 oct down every 30 seconds).
In the feedback loop, an A-108 is inserted with bandpass out, no emphasis and manually changed filter frequency. BBD output is sent into another A-108 (filter frequency is controlled by BBD frequency CV out), the 48dB out is then sent into DAW.
Andreas
Last edited by AndreasKrebs on Sat Sep 25, 2010 5:26 am, edited 1 time in total.
- AndreasKrebs
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Same patch as above, but this time with an A-188-2 (396 stages tap used):
http://www.andreaskrebs.de/assets/media/A-188-2.mp3
Around 3:00 you can hear that there's a little bit more noise / crosstalk involved with the tapped BBD. (Nothing a Stratocaster player would even care...)
Andreas
http://www.andreaskrebs.de/assets/media/A-188-2.mp3
Around 3:00 you can hear that there's a little bit more noise / crosstalk involved with the tapped BBD. (Nothing a Stratocaster player would even care...)
Andreas
Last edited by AndreasKrebs on Sat Sep 25, 2010 5:27 am, edited 1 time in total.
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-EDIT-
Lovely thread!
Re: Acoustic modular sounds
Hey, Ian, you still around??frijitz wrote: ↑Sat Sep 18, 2010 11:22 amNot sure exactly what you are looking for, but I did a lot of stuff like this at one time:Monobass wrote:I like those modular sounds that tread that edge between sounding electronic and sounding somehow acoustic in nature.
http://home.comcast.net/~ijfritz/sf_sc1.mp3
http://home.comcast.net/~ijfritz/sf_sc1.mp3
Ian
Re: Acoustic modular sounds
There are basically two classes of instruments: instantaneously excited (plucked or struck) and continuously excited (bowed or wind instruments). Hard to think of another category right now. The Macintyre-Woodhouse paper cited above seems to focus on the continuously excited instruments with the feedback loop. But here you need the right kind of controller because you don't just hit something and let it go. The performer has to be actually in feedback with the instrument -- all 'expression' comes from this. Other than having the performer actually use a bow or wind controller, I'm not sure how you would model this aspect.
But for the instantaneously excited instruments, I think the most important ingredient is simply a fast envelope, so you get that surface fidelity and crispness. The problem is everything today is marketed as fast, despite almost nothing being actually so. Even the Minimoog and SEM envelopes are too slow, the acoustic element only comes out when you record a sound and speed it up 2x or 4x. Minimoog also has a deliberately 'blunt' attack, with a nonzero constant region. 2600 or Serge DSG (when used as an AD generator, with feedback for exponential shape) perhaps are fast enough. But this kind of 'crisp' attack is otherwise very hard to find. When it's there and you have a complex timbre or even with a simple pulse wave, the result can really fool you sometimes.
But for the instantaneously excited instruments, I think the most important ingredient is simply a fast envelope, so you get that surface fidelity and crispness. The problem is everything today is marketed as fast, despite almost nothing being actually so. Even the Minimoog and SEM envelopes are too slow, the acoustic element only comes out when you record a sound and speed it up 2x or 4x. Minimoog also has a deliberately 'blunt' attack, with a nonzero constant region. 2600 or Serge DSG (when used as an AD generator, with feedback for exponential shape) perhaps are fast enough. But this kind of 'crisp' attack is otherwise very hard to find. When it's there and you have a complex timbre or even with a simple pulse wave, the result can really fool you sometimes.
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