sono

I'm having troubles with tuning a stringresonator i made (karplus strong). I've tried many things, analyzed frequencies, looking at the vectorsize...

But i can't get it right, even can't even get a clear octave out of it.

tuning-stringresonator-karplus-strong

I've been on this case for a while. I asked Luke Dubois, who 

bassically, said that it was technically impossible but suggested 

adding a tiny bit of noise to the delay time and then everything 

the reason is A, that all frequencies dont fall easily into a 

specific number of samples and B, the vector thing.

I've been on this case for a while.  I asked Luke Dubois,  who  
bassically, said that it was technically impossible but suggested  
adding a tiny bit of noise to the delay time and then everything  
sounds in tune.

the reason is A, that all frequencies dont fall easily into a  
specific number of samples and B, the vector thing.

> I'm having troubles with tuning a stringresonator i made (karplus strong). I've tried many things, analyzed frequencies, looking at the vectorsize...

> But i can't get it right, even can't even get a clear octave out of it.

> Does anybody know how to this properly?

I had exactly the same problem. The reason is that the feedback is 

limited to a whole number of samples. This will give you a very limited 

resolution frequency wise. On thing is to round properly, that helps, 

but its still out of tune, the other is to upsample within a poly~ to 

get a better resolution. I tried to get a sort of interpolation by 

varying the feedback length every x loops by one sample...

But as I look at your patch ,you don't calculate the delay at all...

The delay will determine the pitch in the karplus strong...

poul wrote:
> Hi,
>
> I'm having troubles with tuning a stringresonator i made (karplus strong). I've tried many things, analyzed frequencies, looking at the vectorsize...
>
> But i can't get it right, even can't even get a clear octave out of it.
>
> Does anybody know how to this properly?

I had exactly the same problem. The reason is that the feedback is 
limited to a whole number of samples. This will give you a very limited 
resolution frequency wise. On thing is to round properly, that helps, 
but its still out of tune, the other is to upsample within a poly~ to 
get a better resolution. I tried to get a sort of interpolation by 
varying the feedback length every x loops by one sample...

But as I look at your patch ,you don't calculate the delay at all...
The delay will determine the pitch in the karplus strong...

-- 
Stefan Tiedje------------x-------
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Quote: Stefan Tiedje wrote on Fri, 27 October 2006 01:21

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> But as I look at your patch ,you don't calculate the delay at all...

> The delay will determine the pitch in the karplus strong...

uhm, of course i calculate the delay!, take another look :)

but i have the solution allready -> teeth~ (thanks roman!)

the only point with teeth is that the feedbackline is inside the object so you can't manipulate it, with a filter for instance

Quote: Stefan Tiedje wrote on Fri, 27 October 2006 01:21
----------------------------------------------------

> But as I look at your patch ,you don't calculate the delay at all...
> The delay will determine the pitch in the karplus strong...
>
> Stefan

> uhm, of course i calculate the delay!, take another look :)

but you can't get it shorter than the vector size... And you don't need 

to compensate, as if the delay is longer than the vector size, it will 

I looked at my solution and I stuck with tapin~/tapout~ for the same 

reson as you did (a filter in the feedback)

But I used a simple onepole~ and put all into a poly~ with vs 8. That 

way I got reasonable good tuning even in the high range. And didn't need 

to have the complete patch at that expensive vector size...

poul wrote:
> uhm, of course i calculate the delay!, take another look :)

yeah, got it...
but you can't get it shorter than the vector size... And you don't need 
to compensate, as if the delay is longer than the vector size, it will 
be correct...
I looked at my solution and I stuck with tapin~/tapout~ for the same 
reson as you did (a filter in the feedback)
But I used a simple onepole~ and put all into a poly~ with vs 8. That 
way I got reasonable good tuning even in the high range. And didn't need 
to have the complete patch at that expensive vector size...

Tuning Stringresonator (karplus strong)