Sample Rate Conversion

SRC is often used in DAC's. The reasons are explained here.
In PC audio it is needed when your soundcard supports 48 kHz only and you play a (ripped) CD (44.1 kHz).
The mathematics are complex. If you can read this ( Shannon's sampling theorem ):

You might try The Digital Audio Resampling Home Page'', by Julius O. Smith III.

 

Asynchronous SRC can provide very good jitter rejection but that it will add some distortion and noise to the signal.

ASRC can be made with extremely high dynamic range and SNR, but will then inevitably be of very high complexity.

The ups and downs of arbitrary sample rate conversion - Ivar Løkken, 12/4-05.

Test

Infinite Wave tested a lot of implementations.

SRC explained

SRC Comparisons

 

Some examples of a swept sine wave with -6 dbFS peak amplitude, spanning the frequency range from 0 to 48 kHz for 8 seconds

 

Secret Rabbit Code 0.1.2 (ZOH)

 

Logic8 (Tiger)

R8brain Free

Obvious SRC implementation has its impact on sound quality.

 

Benchmark Media provides an example of the impact of sample rate conversion in OSX 10.4.6

 

The distortion seen in this graph is solely caused by sample-rate converting from 48kHz to 44.1kHz. As seen in the graph, the signal-to-noise ratio went from 130dB to less then 80dB!