Thanks
@amirm . The H and V contour (polar) plots look good and my ears agree
KEF did a great job with the cabinet design and voicing. KEF has a nice design doc about these attached. My nearfield measures, with no gating, look similar too:
Confirm that they roll off pretty quickly at 100 Hz and down -10 dB by 40 Hz. This is in the same room where I can get down to -3 dB at 6 Hz with subs. A pair of (sub)woofers work well with these speakers, mind you 80 Hz XO point is pushing it as you may get a hole there as the LS50's struggle to make to 80 Hz. 100 Hz would make a better XO point (I have tried, 80, 90, 100 Hz), but need to keep the subs close to the LS50's. Rythmik L12's work really well with these, but I would love to hear a pair of Rythmik F8's paired with these and a much higher (woofer level) XO point, like 150Hz or even 200 Hz.
While the voicing is a little forward on axis, a wee bit of eq can straighten that out np. I personally love the voicing on these, but after I reviewed
Purifi's PTT6.5" woofer in an eval kit, the Purifi woofer smokes the LS50 woofer/midrange driver with real extended response to 32 Hz, go considerably louder, with a lot less distortion. It is not even close when compared side by side and I own the LS50's. I hope you get a chance to measure one of Purifi's eval kits...