Originally Posted by pase22
1) Just leave it at 8ohms, it'll be fine.
2) My crossover sweet spot is 90hz. You should experiment between 90-110hz and pick what you like best.
3) LS50's do benefit from a good power amp, but will run and sound good with your X2400H. You'd need pre-outs so you have to upgrade to an X3400/3500 if you want an external amp. You do however get audyssey XT32 and dual sub eq with the X3400/3500.
I also have the crossover at 90hz, on my 2-channel NAD M10 running Dirac Live with my LS50's. Seamless integration with my KEF Kube 10b sub.
KEF R500, R200C, R100, R50, SVS SB2000 sub, NAD T758v3 AVR, LG UP875 4K BlueRay, Samsung UN55JU6500F 4K LED TV, KEF M500 headphones, Sony CDP-CE500 CD changer. Office: NAD M10, KEF LS50, KEF Kube 10b, Pro-Ject RPM1 TT w/ Ortofon 2M Red. Guest room: Hafler 300 L-R, KEF Reference Model 100 center, KEF iQ10 surrounds, modded M&K V-90 sub, Bluesound Vault 2.