Two solutions:

1) You compute the whole track, read the max amp value given at the end,
compute the multiplication factor so that it gets around 32500 (16bit
resolution/2) and modifiy the orchestra so that the left and right
channel gets scaled before output.

2) (Ready Rick ? ;-) You can use the dam opcode to work as a limiter and
avoid you sound volume gets ever over a given threshold. I don't have
the description handy but if you want, I can drop you a sample tonight.
If you also could drop me the orc/sco, I would be interested.

Hope this helps,

Marc.

David Schuyeteneer wrote:
> 
> How can I let Csound calculate to overall volume of it's 
> SCORE in order to avoid unwanted distortion ?