Super Street Fighter IV: Arcade Edition Setup:

Luckily Capcom® fixed the keyboard problem found in Street Fighter IV in Super Street Fighter IV: Arcade Edition™ (make sure you have the latest game patch). 

  • Be sure to have your X-Arcade plugged in before starting the game
  • Go to Options>Controller Setup and you will see at the top it says 'Keyboard 1'. If you press your keyboard's Right-Arrow key it should now say 'Keyboard 2'. If not, then you need to restart the game with the X-Arcade already attached, 
  • See X-Arcade Layout. Set up the player 1 side of the X-Arcade controller as Keyboard 1, and player side as Keyboard 2. Simply hit enter on your keyboard on the action you want to assign, and then press the button on the X-Arcade  that you wish to perform that action.

Street Fighter IV Setup:
Unfortunately Capcom® did not give much thought to the control options in Street Fighter IV for PC. For example, you cannot play with 2 players on one keyboard or a keyboard encoder like have been used in many brands of game controllers for many years. Also you can't use your custom keys on the Character Select screen. 

To work around these limitations you can simply make the X-Arcade work as a gamepad instead.