Hi, I am trying to install a Custom sAPO for providing custom audio effects to the speakers. For this, I am using sysfx.inf file obtained from location <WinDDK>\7600.16385.1\src\audio\sysfx\Inf\. I am stuck with a few issues in this approach : - I am not able to install it for a USB audio device connected to the system. Is there any modification required to be done to the sysfx.inf file for this? - After successful installation of Custom sAPO for a HD Audio Device, if a new audio device is plugged in, then how can I address it (to install my custom sAPO for it as well)? - Also, in some cases audio devices in windows system comes with drivers like Realtek Sound Manager. Is it possible to apply my sAPO effects to these as well ? Note that I'm not developing my our own audio driver for high definition (HD) or USB speaker. My approach here is to just update the existing audio driver using sysfx.inf file to apply audio effects. Regards, Vinayak S