I was able to get this fixed. Thanks to DJRobX for your insight.
It was suggested that my computer was now passing the game sounds to my speaker setup's center channel.
Using a 7.1 setup, I have L, R, SL, SR, FL, FR, and Sub. But that is 6.1. There is the center channel which SSF does not use. SSF, i.e. mechanical sounds, worked just fine because it was passing these to the correct surround sound speakers.
But game sounds, no. Those were now, for some reason, being passed to the non-existent center speaker.
I tested this theory out by setting VPX, Windows, and my sound card all to 2 channels. Doing that, i was able to confirm that roms sounds were playing, as I could hear them from the L & R speakers.
So the question is, why did they all of a sudden start to get routed to the center speaker. I don't know. I never was able to figure that out.
The solution however, was to install Equalizer API. This API uses an internal channel routing solution regardless of how your computer otherwise wants to direct it. Just installing the software fixed the problem.
Other solutions offered, which probably will work for someone (but it didn't for me) was simply disabling the center channel in the windows speaker configuration. I can see how that could work, it just didn't for me.
DJRobX also said some people are able to solve the center channeling through "phantom channeling" in their DSP settings. This wasn't an option for me in my soundcard software. He also said that if I install Equalizer API, it may work just because of the install, but said some people actually need to configure EQAPI to send the C sounds to L and R. Either way, the result is the same.
So anyways, thank you to everyone. I don't know why this happened all of a sudden, but I'm appreciative there are very smart and helpful people who were willing to take time to help me through it.