Defining Audio Connections
To be able to play back and record audio in WaveLab Pro, you must specify how the internal input and output channels in WaveLab Pro are connected to your sound card and which device you intend to use for audio playback and recording.
You can define the buffer settings for your device as well as set up connections to external gear, such as external effects units. You should select at least two channels for stereo playback and recording.
If you have no third-party audio card, you can select the Windows MME driver or Built-in Audio (Mac) options. You can also use MME with most third party audio cards, with the advantage that you can record and play at different sample rates. However, Windows MME drivers do not allow audio monitoring in the Recording dialog or multichannel operation, and other drivers generally offer better sound quality and performance.