Core Audio

Core Audio is Apple's API for implementing audio features in applications for OS X, and is used by Media Center to access your audio device.

Core Audio is capable of providing bit-perfect output up to 32-bitdepth, at low latency, with no resampling at any sample rate. It also includes a lot of optional capabilities like sample rate conversion, audio processing units, and other effects, but JRiver does not use these features and implements its own high-quality DSP.