[PD] making puredata headphone-safe

Jonathan Wilkes jancsika at yahoo.com
Tue Aug 30 03:10:21 CEST 2011


----- Original Message -----
> From: Mathieu Bouchard <matju at artengine.ca>
> To: Ed Kelly <morph_2016 at yahoo.co.uk>
> Cc: PD List <pd-list at iem.at>
> Sent: Monday, August 29, 2011 8:04 PM
> Subject: Re: [PD] making puredata headphone-safe
> 
> On Mon, 29 Aug 2011, Ed Kelly wrote:
> 
>>  The problem is that some objects can generate unstable errors that are 
> orders of magnitude greater than normal audio signals. Then there is a signal 
> that maybe goes between +/- 100000 rather than +/- 1, and the volume control 
> makes little difference.
> 
> It's much, much worse than that. If you have anything that multiplies the 
> amplitude of the signal by 1.0001 at every sample, the amplitude gets 82 times 
> louder every 44100 samples, and it will go beyond 8e+37 and rounded to infinity, 
> where no multiplication by a fraction can possibly fix it.

So why not always have [clip~ -1 1] before and/or after your pd master volume control? 
Could the distortion resulting from clipping out of range values possibly result in a 
signal anywhere near as loud as what you're describing?  Or would adjusting the 

master volume to an acceptable level for the loudest possible clipped sound result in too 

small a dynamic range?


-Jonathan


> 
> that's quite a few billion billion billion.
> 
> It's easy to get there. Put the wrong number in [*~] in a delay-loop, or put 
> the wrong number in [rpole~], ...
> 
> _______________________________________________________________________
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