While using the system you may find that the audio appears to be coming from the projector as opposed to the speakers connected to the system. This usually comes about as a result of the audio driver for the computer reverting to its default setting i.e. utilising the HDMI connection to transmit audio as opposed to the 3.5mm audio cable that is connected to the speaker amplifier within the system.
This Guide will outline how you can go about correcting this should this issue arise.
To Start with Press the Windows Key on the keyboard to bring up the taskbar at the bottom of the projection. Move the mouse down to the bottom right-hand corner of the projection, next to the Time & Date, and Right-click on the Volume Icon. From there select Open Sound Settings.
On the next window, you will find parameters that can be adjusted for the currently selected Output device, if as we suspect the sound is being directed to the projector you will likely see Optoma XGA (Nvidia High Definition Audio) selected. In order for us to change this and ensure this does not happen again, we will need to set the speakers as the default device and disable the HDMI audio connection. To do this scroll further down this window and under Related Settings, select Sound Control Panel.
Once open you will likely find the Sound Control Panel in a state as seen below:
The green tick seen here indicates which device is set as the default connection. If this is on the Optoma XGA device or any other device besides the Speakers/Headphones then this needs to be changed. Simply Right Click on Speakers/Headphones and Select: Set as Default Device.
Once this is done you should see the green tick on the Speaker Connection. To ensure the PC does not revert back to the HDMI connection we can now disable that device. To do so Right Click on Optoma XGA, select Properties. On the next window that pops open, you will likely be on the General Tab at first. If not click over onto General. Under Controller Information click on the Properties button. This will pop open another window likely on the General Tab again. Click onto the Driver tab, from here you will see a list of options simply select Disable Device. You will then be prompted with a confirmation warning stating disabling the device will cause the device to stop functioning, and whether you want to continue, select Yes and then OK on the preceding windows.
Once this is done you should be back to the Playback Devices within the Sound Control Panel with just the Speakers/Headphones device selected as the Default Device and all other devices disabled. Lastly to make sure this device is functioning as expected you can then Right Click on this device and select Test this will cause the PC to play a test tone across the 2 speakers connected to the system. If these play as expected then the issue has been resolved.