Sample-Rate Conversion And Prism Sound Ssrc - Prism Sound ADA-8 Operation Manual

Prism Sound ADA-8 Multi-channel A/D D/A Converter Operation Manual - Revision 1.00
This is useful in certain situations. For example, it may be desirable for a digital recording to
be made 'louder' than would be possible if its loudest transients had to be accurately
represented on the digital medium. Or where the dynamic range of the recording medium is
limited, and perhaps levels are not easily controlled, such as when recording a live
performance onto DAT.
In these situations, the Prism Sound Overkiller acts in a uniquely progressive manner, which
gives it unrivalled capacity to soak up large transient overloads without any noticeable
distortion, whilst protecting the A/D converter from overmodulation.
There is no need for the Overkillers' thresholds to be manually adjusted; the ADA-8's software
automatically adjusts the thresholds according to the selected analogue line-up level and trim.

7.6 Sample-rate conversion and Prism Sound SSRC

Sample-rate converters have a bad name amongst audio engineers. They are regarded as
sounding so bad that it is often preferred to rate-convert through analogue using good quality
D/A and A/D converters.
The Prism Sound Synchronous Sample Rate Converter (SSRC) brings new quality to the rate
conversion process. The plot below shows a 997Hz tone at –1dBFS being converted from
96kHz sample rate to 44.1kHz sample rate by Prism Sound SSRC:
As can be seen from the plot, the largest spurious component is at –157.63dBFS, which
represents a huge improvement over competitive asynchronous rate converters, whose
imprecise conversions produce large and obtrusive aharmonic distortion components which
have given sample rate converters their characteristic 'sound' in the past.
The Prism Sound SSRC is included with the DSP Processing Suite, which requires fitment of
a DSP Expansion Module in the ADA-8.
© Prism Media Products Limited, 2002 Page 1.34