Quadratic Equation

The signal doesn't seem to like being plugged back into the [+~] element- no sound goes through to the [dac~]. How come? Everything else works fine. The second argument of [delay~] sets the inital delay time to about 11 ms, which should produce some kind of decayed, plucked sound.

physical-modelling-system-problem

So the signal path has to be delayed by one sample - yet the [delay~] object is already delaying it by 400? I don't understand...

a dsp chain (ie a serie of msp object connected one to the other) can't loop on itself.

using a combination of tapin~ tapout~ instead of delay~ solves this as well.

> So the signal path has to be delayed by one sample - yet the [delay~] object is already delaying

a dsp chain (ie a serie of msp object connected one to the other) can't loop on itself.
using a combination of tapin~ tapout~ instead of delay~ solves this as well.
//yac

>
> Perfect, thankyou.
>
> So the signal path has to be delayed by one sample - yet the [delay~] object is already delaying
> it by 400? I don't understand...
>


The trouble with tapin~ and tapout~ is that small delay times don't register. Plus, a [delay~] module is more elegant and fitting with the algorithmic descript of Karplus-Strong.

One limitation of this system seems to be that even the shortest delay time (1 sample) doesn't produce a particularly high pitch. Any suggestions? Here is an expanded model, just hit the preset to get going:

On 22-Aug-2006, at 14:19, r.julien wrote:

> The signal path has to be delayed by one sample (if I'm correct).

There has to be a break of one sample *vector*. That is typically a 

lot longer than one sample. This has been covered on the list dozens 

t=msg&goto=64824&rid=0&S=ddb91f73fbf711b63acae91df9099b42#msg_64824

t=msg&goto=63688&rid=0&S=ddb91f73fbf711b63acae91df9099b42#msg_63688

t=msg&goto=59586&rid=0&S=ddb91f73fbf711b63acae91df9099b42#msg_59586

t=msg&goto=58165&rid=0&S=ddb91f73fbf711b63acae91df9099b42#msg_58165

t=msg&goto=54963&rid=0&S=ddb91f73fbf711b63acae91df9099b42#msg_54963

BTW: you can set the sample vector size to a single sample with an 

msp;-message. Watch your CPU usage go up.

Peter Castine +--> Litter Power & Litter Bundle for Jitter

Interface Building for |home | chez nous|

Max/MSP Extremely cool |bei uns | i nostri|

On 22-Aug-2006, at 14:19, r.julien wrote:
> The signal path has to be delayed by one sample (if I'm correct).

There has to be a break of one sample *vector*. That is typically a  
lot longer than one sample. This has been covered on the list dozens  
of times, for instance:

https://cycling74.com/forums/index.php? 
t=msg&goto=64824&rid=0&S=ddb91f73fbf711b63acae91df9099b42#msg_64824

https://cycling74.com/forums/index.php? 
t=msg&goto=63688&rid=0&S=ddb91f73fbf711b63acae91df9099b42#msg_63688

https://cycling74.com/forums/index.php? 
t=msg&goto=59586&rid=0&S=ddb91f73fbf711b63acae91df9099b42#msg_59586

https://cycling74.com/forums/index.php? 
t=msg&goto=58165&rid=0&S=ddb91f73fbf711b63acae91df9099b42#msg_58165

https://cycling74.com/forums/index.php? 
t=msg&goto=54963&rid=0&S=ddb91f73fbf711b63acae91df9099b42#msg_54963

BTW: you can set the sample vector size to a single sample with an  
msp;-message. Watch your CPU usage go up.

--------------    http://www.bek.no/~pcastine/Litter/    -------------
Peter Castine             +--> Litter Power & Litter Bundle for Jitter
                                Universal Binaries on the way
iCE:  Sequencing,  Recording &
       Interface  Building  for                   |home    | chez nous|
       Max/MSP   Extremely cool                   |bei uns |  i nostri|
       http://www.dspaudio.com/                   http://www.castine.de

You could put the section of the DSP graph that has feedback into a 

separate patch, load it using poly~, and set the vector size of the 

poly~ to be small, rather than your whole graph.

The inputs of the sub-patch for poly~ will need to be in~ objects 

(and the outlet will be out~ objects). If you saved it as 

KarplusStrong.pat, and load it in poly~ like this:

Then that section of the dsp graph will process at a vector size of 

2. Actually I expect a vector size of 4 or 8 will give you plenty of 

headroom for high frequencies; Nyquist for a vector size of 8 at 

44.1kHz gives a theoretical max frequency of 2,756.25 Hz.

On Aug 22, 2006, at 8:57 AM, Peter Castine wrote:

> On 22-Aug-2006, at 14:19, r.julien wrote:

>> The signal path has to be delayed by one sample (if I'm correct).

> There has to be a break of one sample *vector*. That is typically a 

> lot longer than one sample. This has been covered on the list 

> t=msg&goto=64824&rid=0&S=ddb91f73fbf711b63acae91df9099b42#msg_64824

> t=msg&goto=63688&rid=0&S=ddb91f73fbf711b63acae91df9099b42#msg_63688

> t=msg&goto=59586&rid=0&S=ddb91f73fbf711b63acae91df9099b42#msg_59586

> t=msg&goto=58165&rid=0&S=ddb91f73fbf711b63acae91df9099b42#msg_58165

> t=msg&goto=54963&rid=0&S=ddb91f73fbf711b63acae91df9099b42#msg_54963

> BTW: you can set the sample vector size to a single sample with an 

> msp;-message. Watch your CPU usage go up.

> Peter Castine +--> Litter Power & Litter Bundle for Jitter

> Interface Building for |home | chez nous|

> Max/MSP Extremely cool |bei uns | i nostri|

You could put the section of the DSP graph that has feedback into a  
separate patch, load it using poly~, and set the vector size of the  
poly~ to be small, rather than your whole graph.

The inputs of the sub-patch for poly~ will need to be in~ objects  
(and the outlet will be out~ objects).  If you saved it as  
KarplusStrong.pat, and load it in poly~ like this:

Then that section of the dsp graph will process at a vector size of  
2.  Actually I expect a vector size of 4 or 8 will give you plenty of  
headroom for high frequencies; Nyquist for a vector size of 8 at  
44.1kHz gives a theoretical max frequency of 2,756.25 Hz.

> On 22-Aug-2006, at 14:19, r.julien wrote:
>> The signal path has to be delayed by one sample (if I'm correct).
>
> Almost.
>
> There has to be a break of one sample *vector*. That is typically a  
> lot longer than one sample. This has been covered on the list  
> dozens of times, for instance:
>
> https://cycling74.com/forums/index.php? 
> t=msg&goto=64824&rid=0&S=ddb91f73fbf711b63acae91df9099b42#msg_64824
>
> https://cycling74.com/forums/index.php? 
> t=msg&goto=63688&rid=0&S=ddb91f73fbf711b63acae91df9099b42#msg_63688
>
> https://cycling74.com/forums/index.php? 
> t=msg&goto=59586&rid=0&S=ddb91f73fbf711b63acae91df9099b42#msg_59586
>
> https://cycling74.com/forums/index.php? 
> t=msg&goto=58165&rid=0&S=ddb91f73fbf711b63acae91df9099b42#msg_58165
>
> https://cycling74.com/forums/index.php? 
> t=msg&goto=54963&rid=0&S=ddb91f73fbf711b63acae91df9099b42#msg_54963
>
> BTW: you can set the sample vector size to a single sample with an  
> msp;-message. Watch your CPU usage go up.
>
>
>
> --------------    http://www.bek.no/~pcastine/Litter/    -------------
> Peter Castine             +--> Litter Power & Litter Bundle for Jitter
>                                Universal Binaries on the way
> iCE:  Sequencing,  Recording &
>       Interface  Building  for                   |home    | chez nous|
>       Max/MSP   Extremely cool                   |bei uns |  i nostri|
>       http://www.dspaudio.com/                   http://www.castine.de
>
>


> Then that section of the dsp graph will process at a vector size of 2. 

> Actually I expect a vector size of 4 or 8 will give you plenty of 

> headroom for high frequencies; Nyquist for a vector size of 8 at 

> 44.1kHz gives a theoretical max frequency of 2,756.25 Hz.

The problem isn't the highest available pitch, its the resolution of the

pitches. You won't get them tuned (even if you relate your key to the

sample rate...). But inside a poly you can also use a higher sample rate

lists@grahamwakefield.net wrote:
> Then that section of the dsp graph will process at a vector size of  2.  
> Actually I expect a vector size of 4 or 8 will give you plenty of  
> headroom for high frequencies; Nyquist for a vector size of 8 at  
> 44.1kHz gives a theoretical max frequency of 2,756.25 Hz.

The problem isn't the highest available pitch, its the resolution of the
pitches. You won't get them tuned (even if you relate your key to the
sample rate...). But inside a poly you can also use a higher sample rate
which helps, but needs even more CPU...

-- 
Stefan Tiedje------------x-------
--_____-----------|--------------
--(_|_ ----|-----|-----()-------
-- _|_)----|-----()--------------
----------()--------www.ccmix.com

> > Then that section of the dsp graph will process at a vector size of 2.

> > Actually I expect a vector size of 4 or 8 will give you plenty of 

> > headroom for high frequencies; Nyquist for a vector size of 8 at 

> > 44.1kHz gives a theoretical max frequency of 2,756.25 Hz.

well the nyquist at 44.1khz samplingrate is always the same, 

the vector size will not help much here. :)

it seems you mixed up downsampling with vector size, because

2.7 khz nyquist is what you get at [poly~ foo down 8]

> > Then that section of the dsp graph will process at a vector size of  2.
> > Actually I expect a vector size of 4 or 8 will give you plenty of  
> > headroom for high frequencies; Nyquist for a vector size of 8 at  
> > 44.1kHz gives a theoretical max frequency of 2,756.25 Hz.

well the nyquist at 44.1khz samplingrate is always the same, 
the vector size will not help much here. :)

it seems you mixed up downsampling with vector size, because
2.7 khz nyquist is what you get at [poly~ foo down 8]

Physical Modelling system problem