Lots of good recommendations here. Just wanted to point out, however, that for among KEF speakers, you should be looking at the R3 and maybe LS50 Wireless (if active is a consideration), not the LS50. Of these two, I definitely prefer the R3. Subjectively, the LS50 Wireless has maybe a tiny edge in soundstage, but the R3 is definitely the more neutral-sounding of the two. I'd put them both within the 'neutral' ballpark though.
Here's the R3:
Here's the LS50 Wireless (note I'd only measured this up to 60 degrees off axis, as opposed to 75 for the R3):
I believe both are good measuring speakers, but I think the LS50W's notch at 1.7K is more noticeable than the two shallower bumps in the R3's midrange.
KEF aside, I've always heard good things about ascend acoustics. You'll also want to look into the Buchardt S400, another good-measuring favorite in the price range (which I'm currently enjoying a lot for review). With the KEFs, I do like that they maintain very similar vertical dispersion too.