Please excuse my noviceness....

What exactly does the amplitude (p4) value stand for?  What does it
represent?  What is the total amount of amplitude that can be given without
distortion?

Thanks,
Christian Guirreri and Musc428 at Radford University

Any p value beyound p3 stands for whatever YOU decide it stands for. If you
want p4 to be the amplitude of a given note, YOU have to write the
instrument in such a way that it is.

There is no easy answer to the total amplitude that can be given without
distortion. The maximum value without distortion for all of your
instruments added together at their peak is either 32767 or -32768, but how
your instruments will add together and how their amplitudes should be set
is an EXTREMELY situation dependent problem. You either need to experiment
or use one of the Csound versions that lets you generate floating point
samples and then scales them to a max of 32767. Hope this helps.

At 7:46 PM -0400 9/10/98, Christian Guirreri wrote:
>Please excuse my noviceness....
>
>What exactly does the amplitude (p4) value stand for?  What does it
>represent?  What is the total amount of amplitude that can be given without
>distortion?
>
>Thanks,
>Christian Guirreri and Musc428 at Radford University
>cguirrer@runet.edu


-------------------------------------------------------------------------------
Erik Spjut (pronounce ju as long u or yew) - Associate Professor of Engineering
and  Associate Director for Engineering Computing,  Center for Design Education
Harvey Mudd College, Claremont, CA 91711-5990  USA
Erik_Spjut@hmc.edu      Ph & Voice mail (909) 607-3890      Fax (909) 621-8967

Csound usually uses 16 bit amplitude resolution, the same as CD quality
audio.  This means that there are 2^16 = 65536 possible amplitude values
for a sample, ranging from -32768 to +32767 (with one value reserved for
zero.)  The dynamic range is therefore about 48dB (I think.)

The value you input for amplitude, in most cases p4, is the
maximum amplitude that any sample reaches. If you have a bunch of waves
happening at the same time, they add together and you have to be careful
you don't max out.  The total amplitude of all the waves at a given time
can't exceed 32767.  If a sample's amplitude spikes above 32767, csound
will set it at 32767 and you will have some distortion and a message about
samples out of range.  Hope that helps.

			Kevin Gallagher, kgallagh@astro.temple.edu 
			Web Address - http://astro.temple.edu/~kgallagh

On Thu, 10 Sep 1998, Christian Guirreri wrote:

> Please excuse my noviceness....
> 
> What exactly does the amplitude (p4) value stand for?  What does it
> represent?  What is the total amount of amplitude that can be given without
> distortion?
> 
> Thanks,
> Christian Guirreri and Musc428 at Radford University
> cguirrer@runet.edu
>