Crossover for different speakers and Sub (Kef)

I have a Denon 2807 and KEF KHT 3005 speakers

I have set my speakers to a crossover of 100 & 90 on my Denon reciever
through advanced set up. It asks me to set the crossover for the
LFE...im assuming this to be approx the same setting as the speakers?
It asks me the crossovers for the diff speakers
e.g Centre - 100; Front L - 90 Front R - 90
Surround L - 100; Surround R - 100; LFE - ???

LFE refers to low frequency effects, namely the low-rumbling sound effects manufactured for movies. Typical crossover for subs is at 80hz, but feel free to try out different settings at the best crossover point will be sensitive to your specific speakers, sub, and room acoustics.