It surprises me that people don't understand that there is a reason why every other manufacturer uses a separate woofer and tweeter. The tweeter is mounted on the woofer, which changes position with signal. There is really no way an LS 50 can sound very good. Think about it, and then listen.
There are pros and cons to a coaxial driver and every system needs to be considered as an overall system, not just 1 component. The LS50 do have small drivers and the excursion needs to be low to sound their best since the cone acts as a waveguide for the tweeter. This is why they really need to be crossed over to a sub to sound their best, if you only have a 2nd order high pass I would cross between 100-120Hz.