It’s probably also worth mentioning that FxSound’s Ambience effect purposefully adds a form of echo known as reverb, a.k.a. reverberation, to your audio output, while the Surround Sound effect widens the stereo spread, which could further exacerbate echo issues.
So try keeping the Surround Sound effect slider set under 5, and the Ambience slider in particular as low as possible, in order to eliminate echoes.
