Also, here’s a list of simple general settings to check first:
Make sure you have the latest version of FxSound installed (v184.108.40.206) from fxsound.com ;
Visit the manufacturer’s website and download software specifically made for your headphones and/or speakers;
Try running FxSound as Administrator;
In Windows Sound Settings, make sure all your devices match at the setting “24 bit 48000 Hz” (max);
In Windows Sound Settings, make sure the FxSound device is set as the Default Device;
In Windows Sound Settings, disable Exclusive Mode for all devices (Playback ànd Recording);
In Windows Sound Settings, disable all Enhancements including Loudness Equalization for all devices (except for FxSound which doesn’t have this tab);
In Windows Sound Settings, disable Hardware Acceleration;
In Windows Sound Settings, disable all devices you don’t use, including the hidden ones.
Please run through these steps first, and report back with your results.
In all honesty, I must say, there have been a few other users who had the same problem, and no definitive solution has yet been found.