I would look at updating your audio card drivers, firmware and run windows update several times (also check optional updates) first as a matter of routine. You then might want to rename AUD.INI and set up Sonar audio preferences again (google for details).
Is it possible to put your specs in your signature? (check mine).
 
Thanks...

Any non-default Visual Effects or other settings in System Properties > Advanced > Performance?

Everything is up to date.
 
I uninstalled X3 clearing the registry and reinstalled X3a then X3e which seems to fix this issue, though some other issues remain.
 
Proof that an install can go bad.