In article , Arny
Krueger
wrote:
"Jim Lesurf" wrote in message


If you don't employ oversampling or resampling then you don't risk
problems with some intersample peaks being above 0dBFS. Oversampling
and resampling systems need to allow for values as much as 3 or 4 dB
above any individal values in the source stream to avoid overflows.
Using a non-oversampling DAC followed by analogue filters with enough
headroom means the digital system doesn't need this extra 'bit' or so
above 0dBFS.

Intersample peaks above 0 dBFS can easily happen whether or not
oversampling or resampling is used. It is a natural consequence of the
reconstructed data passing through certain data points.

Indeed. However if the DAC does not generate intersample values it doesn't
have to cope with them. That is left for the following analogue stages.

The good news is that they are rare in natural data. Another good reason
not to normalize to 0 dB FS.

Indeed. Alas it does happen. Indeed, reading a computer mag some months ago
I was alarmed to see an 'expert' blandly explaining how to use sotfware to
compress sound levels up to 0dBFS. No sign he had a clue about the problems
this could cause.

Slainte,

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html