Hi,
Gigabyte GA-H61M-D2-B3
Motherboard supports 2/4/5.1/7.1-channel HD audio, whereas Cambridge Soundworks SW320 is 2.1 (only). Hence, the PC should be configured to provide 2.1 Channel output. The audio of your system may be configured to 2.1. So, please check the Realtec Audio sound manager/ configuration from the control panel or from tray (near clock) and set it to 2.1 (2 Channel Stereo Output).
Moreover, audio on your PC may be running on default HD Audio Drivers. So, you may also download/ install the latest drivers for
Gigabyte GA-H61M-D2-B3 Motherboard.
(Refer to download section at the bottom of the page). After installing audio drivers, you would be able to configure the audio.
Hope it helps! Good Luck! Thanks for using Fixya!
CreativeTECH