The reason for this is because a lot of the newer music games take exclusive control of your audio on your PC. Hence why you had to switch to your monitor speaker audio. I had the same problem too.
So I've been playing the game for a bit now. If I close the game and go back to it with the same car. My tuned up car and story progress remains? I didn't even know that a file was being saved.
As soon as I deleted that sv folder. The game started to run for me. However, you need to re-delete it each time when you close and wanna start back the game again. It's kinda annoying
It looks very similar to Mario Kart, where they just use a lan switch to pair the two together. I tried it with my desktop and laptop and had no luck with that.
I downloaded Samurai Shodown VI from this website to load up on NullDC-Naomi and when it runs. I get some weird graphical glitches with the character sprites where they are hidden behind the stage. It's weird. This was one of the only stages where the characters appeared as they should:
So I have extracted the game and placed the DDR12-16 files onto the root of the contents folder and once I run the gamestart-16.bat file and I get this message from CMD and the game never boots up.