@turnbowm
good to know that ls50 is an exception to the usual rule for how to set standmounts at the right height for best performance...
interesting that this speaker poses this interesting tradeoff for a user -- proper imaging height and presentation vs sufficient bass reinforcement... a tough one it seems (i have not heard ls50’s in my own system... don’t own them)
if kef recommends this set up i would defer to that, and disregard my earlier, generic advice
this being said, using a good sub for real bass reinforcement is a solution that has made many a good standmount into world beaters! i suspect that is the way to have the cake and eat it too