The PKEY_AudioEndpoint_Disable_SysFx property specifies whether system effects are enabled in the shared-mode stream that flows to or from the audio endpoint device.

System effects are implemented as audio processing objects (APOs) that can be inserted into an audio stream. APOs are software modules that perform audio processing functions such as volume control and format conversion. Disabling the system effects for an endpoint device enables the associated stream to pass through the APOs unmodified.

For more information about system effects in Windows Vista, see the white papers titled "Custom Audio Effects in Windows Vista" and "Reusing Windows Vista Audio System Effects" at the Audio Device Technologies for Windows website.

This property applies only to the local-effects and global-effects APOs that were installed by the .inf file that installed the audio adapter to which the endpoint device is connected. In addition, this property affects only the target endpoint device—it has no effect on the system effects for any other endpoint devices, even if they connect to the same adapter.

The vt member of the PROPVARIANT structure is set to VT_UI4.

The ulVal member of the PROPVARIANT structure is set to ENDPOINT_SYSFX_ENABLED if system effects are enabled or to ENDPOINT_SYSFX_DISABLED if they are disabled.


Minimum supported client

Windows Vista [desktop apps only]

Minimum supported server

Windows Server 2008 [desktop apps only]



See also

Audio Endpoint Properties
Core Audio Properties