Try looking at
http://www.psxdatacenter.com/
DUNE 2000 NTSC-U info including settings
Wargames Defcon 1 NTSC-U info including settings
Some of the emulation notes are a bit old so some will use ePSXe 1.7.0 for example but you should be ok with ePSXe 1.9.0 that uses the same core with only minor updates/fixes, but if all else fails start off using exactly what is recommended there, with your own tweaking added
P.S. if BGM does not work still after the settings have been changed to what is in the links then give me some info on the files you have for the disc image
Just list the files that make up the disc image of Wargames Defcon 1