wbpy46jctn65 Your dxdiag shows five sound devices: the built-in speakers on your monitor, your headphones, FXSound, an Altavoces system, and a Realtek audio driver for that system. I know you disabled FXSound for testing purposes, but when testing, did you have the speakers and headphones connected? If so, please unplug both and test the game through the monitor's speakers, still with FXSound disabled. I just want to make sure that these devices or their drivers aren't interfering with each other.
The drivers for these devices are older, other than the one for your monitor's speakers (which use the Nvidia sound driver, which in turn gets updated alongside the graphics driver). So it's possible that updating one or more of them would help. But the first step is to test without their devices connected.
If you do need to update these drivers, click Windows key-X, select the Device Manager, expand the Audio category, and click on each device in turn and click Update in the menu. Repeat for the Sound category. Some devices may not have updates, which is fine; the point is to force Windows to check. Restart your computer afterwards.