1. Now we're going to have to check if this is even your problem, you're going to want to right click the game in your steam library and hit "properties", then as the window pops up hit "local files" and choose "browse local files". Once you're in file explorer right click the games application hover over "run with graphics processor" and choose your high end GPU. If this works move to step 2.

2. Now that we know this works we just have to set it to aways use your hgh end GPU. Your going to right click on the games application back in file explorer and hover over "run with graphics processor" now instead of hitting your high end GPU your going to hit "change deault graphics processor". From there just add the game to the GPUs control panel and set it as the default.

I run an Nvidia 960 with Windows 10, if you run AMD I can't help you to much. I had a similar problem with Nitroplus Blasterz about a half a year ago, not a frame rate issue but it just wouldn't launch, someone told me about this method and thought I'd try it with this game after seeing the problems the frame rate and sound.
P.S. Will update with photos, spelling corrections, and new information just thought id get the what i know out there

This is applicable for integrated nvidia gpus found in laptops. happens with practically every blazblue game including cross tag battle.