Can someone explain...

[chuckles]

As I was looking through one of Inventor's files, I noticed that he had this construction

[Kassen]

I'm not sure what you want to know exactly, but what you have there is a single impulse that gets processed by a set of independent filters. After that the whole thing is treated with reverb.

The idea is that BPF's will "ring" to a certain degree after getting "excited" by the impulse so basically you have a set of similar sound sources that all get activated at the same time by the same source to create a sort of "chord" .

Sending the same impulse to the dac multiple times, like in your example, will do the same as having the same signal on a mixer several times (let's disregard effects and eq on mixers here) so that will just result in more volume.

As for how useful doing almost the same thing several times in paralel as compared to the *exact same* thing several times is you can consider for example choirs. Get the nearest girl (asuming your a boy) and sing a simple song with her together or try to hit two pans at the same time using one large wooden spoon (that last example is exactly what we have here).

I could tell you more but I'm not sure exactly what you'd like to know, excuse me if this was trivial.

[chuckles]

Thanks Kassen; I knew I would get a quick and thorough answer here. Everything you explained seems to make sense. Maybe I'm making things too complicated. The confusion in my mind I guess would be if instead of the same impulse i1 being fed into the filters/reverbs/dacs, what would be the difference if instead of repetitions of i1 they were replaced with Impulse i2, Impulse i3, etc. That would confuse me if they did exactly the same thing. Using a single Impulse UG i1 would seem to be the more efficient way to go, if so.

A side question would be: is it legal to create an array of Impulse UGs like other UGs?

I hope I am explaining this coherently. And thanks in advance again!

[Kassen]

Well, in a precise and explicit programing language like ChucK when you have two "identical" things they will behave the same way, exactly.

This is different from some digital modulars like for example Clavia's Nord Modular series where using three identical oscillators will give you a fairly complex wave thanks to the engine randomising the phase at which they start. Clavia uses that as it's a realistic emulation of what happens in "real" synths, if you want that sort of behaviour in ChucK you will have to define exactly what sort of behaviour you want, ChucK is (or rather aims to be) very predictable and consistent.

So; using two impulse fired off at the same time and summed yields the *exact* same result as a single one with a gain of 2. Here Inventor used a single one (as well as a single reverb) in order to save the cpu. Obviously one is also easier to control then five.

About arrays; yes you can! To go even further you can have arrays of anything that's a primitive or a object. Maybe things like "dac" and "blackhole" are exceptions but you can, for example, have a array of Events or strings or Impulse Ugens. If you define your own class you can also have a array of instances of that. You can't, however, have a array of functions, those aren't objects.

So; to create a group of line&file soldiers;

[kkissinger]

For years I've known of the story where programmers modified a battle simulation program for use in Australia by reusing an infantryman class to create a kangaroo class.

And, by golly, snopes says it is a TRUE story.

http://www.snopes.com/humor/nonsense/kangaroo.asp

To make a long story short, they included all the infantryman methods in the kangaroo class -- with hilarious results!

[Kassen]

Funny!

Extending the soldier with a .hop() function would be easy enough but then we run into the issue that ChucK lacks a appropriate (ready made) structure to put kangaroos in, that would have to be more like a group , flock or set then like orderly rank&file.

Such a data structure would be quite good for grains as well, perhaps somebody should make one :¬).

I'm strongly opposed to outfitting ChucK with stinger missiles, at least until stability improves. (I wanted a explosion emoticon here but can't find one quickly')

[dewdrop_world]

Well, it's sort of an explosion. The kind of thing that's likely to happen if you spend too much time looking at code!

James

[kijjaz]

One thing we have to consider here..
is that rechucking (chucking a chucked pair of UGens)
like doing r1 => dac; then r1 => dac; later
.. would not do anything.

You can investigate into this patch and see how it performs.
It will show you that rechucking does nothing new.
But using a Gain, we can make a duplicate of a signal and use it as another source to chuck.

[Kassen]

[Inventor]

[kijjaz]

Kassen: Cheers ^_^

[Kassen]

Inventor; I'm not sure if you're aware of this already but what you are doing is basically "modal synthesis" and is a known way of emulating struck or plucked objects. What you have is roughly a physical model of a string.

What you can also do is emulate the exact pluck-position by tweaking the relative volume of the BPF's. For example, if you would pluck the string at a third of it's length that would exite the second harmonic (three times the fundamental) more then the others. One of the fun things of the way this way of synthesis works is that it's not at all prone to aliasing.

[Inventor]

Aha! So it's called modal synthesis, that is good to know. I had not thought of changing the harmonic content in that way either, I must give that a try.