Your computer may have several installed devices like FAX modems and software synthesizers that
Windows recognizes as sound cards containing audio drivers. You do not want to use these devices for audio input or output. If they are listed as audio drivers in the Preferences
dialog box, you need to disable them.
Disabling a device in Edit > Preferences > Audio - Devices
usually prevents conflicts with other audio devices. Occasionally you may need to disable a device in the Windows Control Panel.
also allows you to choose the sound card whose clock should be used to control recording and playback timing (if you only have one sound card, SONAR automatically uses it). Every sound card’s clock crystal is slightly different, which causes minor differences in the actual playback rate on each card. These differences may lead to slight synchronization problems if you use one card for recording and a different one for playback. Generally, you should choose your highest quality sound card for both recording and playback timing. Note that while some multichannel sound cards have multiple drivers, most sound cards have only a single audio driver.
While you must choose a playback timing master, you can route audio output through any number of
devices at once. For example, suppose your computer has both a high-end audio card and a basic built-in sound card. You should choose the high-end sound card as the record and playback timing master. However, using the buses in the Console or Track views, you could create a headphone or monitor mix and route it through the built-in sound card.