The Audio output is managed in the Hardware tab, audio section.
On PC, it is recommended to use an Asio driver to decrease latency.
A VSTe can be plugged on the audio output.
With non-Asio driver, latency must be tuned at minimum, keeping a good sound quality.

With the choice "auto" in the audio driver, you select the default value, defined during the initialization wizard (menu Help / Initialization ).

Audio output contains between 1 to 7 channels. Each audio-out port can be set on one channel. For example, a simple 5.1 sound card and 3 SF2 enables 5 fully independant channels.

It's possible to record audio output on the disk ( with Asio driver only).
File will be in PCM format, 16 bits 44.1Khz, with wav extension.
File name is defined in the Hardware tab, Audio section.
Recording is active when menu "tool/record" is checked.
The file is flushed when Expresseur exits, or audio is exported.