Steinberg NUENDO 8 I/O 96k Handbuch Seite 36

Thanks to BIT SPLIT and COMBINE the Nuendo 8 I/O 96k preserves full 24 bit resolution
even when working with 16 bit devices. It may happen that the actual recording situ-
ation does not allow a usage of BIT SPLIT/COMBINE. If you use Double Speed (88.2 and
96 kHz), then BIT SPLIT/COMBINE is not available. If you transfer to a 16-bit medium,
the word length is reduced by discarding the lower bits. This truncation causes distor-
tion at the low-level components of the signal.
To combat this 'quantisation distortion', noise at a level corresponding to the least-
significant bit - or below - is added to the signal before truncation, randomly modulat-
ing the signal. This process is called 'dithering'.
If you look at it closely, you will find that Dithering is generally not necessary . When
this issue is discussed, the fact is often not mentioned, that external dithering is un-
necessary if the sum of noise from the source as well as from the A/D converter is
above a certain threshold. And when using DC-free A/D-converters truncating signals
outside the 16-bit range does not cause them to disappear altogether, but only
changes their levels slightly.
Dither is used when reducing the word length from 24 to 20 or 16 bit. Activating the
function PROCESS DITHER is helpful when recording the high resolution signal of the
Nuendo 8 I/O 96k onto any 16 bit destination , preventing distortion at very low levels
caused by truncation. Apart from the above notes, there are other good reasons why
you can safely do without dither in the Nuendo 8 I/O 96k:
• Transferring to 20-bit (such as ADAT XT or O2R) does not require dither, as the maximum dy-
namic range of the Nuendo 8 I/O 96k is 'only' 18.8 bit (or 113 dB), thus fitting into a 20-bit (120
dB) system.
• Transfering data to a computer can be done in 20 or 24-bit word length. Dither then is added at
the very end of the chain, i.e. after all editing and mixing has been done.
Please note that Dithering is most helpful at the end of the recording chain, when
mastering down to 2 tracks and 16 bit.
NUENDO 8 I/O 96k
36 16 bit Operation and Dither