Welcome to the Sound Lab family! Chiming in here as a Sound Lab owner and dealer, I have U-1s and echo what others have said. Playing music 24/7 (low level at night is OK) can speed the process, as can playing of dynamic, bass-rich music as Albert suggests. It will take time for full break-in, at least 300 to 400 hours with a bit more improvement after that, but you will notice increased efficiency and dynamics in the first couple hundred hours or so. If you have questions please feel free to contact me.
Brian
Brian