End game speakers for Yamaha as2100 under 5k new or used

Hi

Cycled through a few now.  

I love the amp and never want to sell.  Its a tank (50lbs) but only rated at 90w.

I only stream now.  Tidal mqa through a lumin d1.   Sometimes CD.    No other hi res.  So redbook or mqa will be it for me.

I like some detail, but like a more relaxed sound that I know.   1\2 of the time its playing in the room in the background, other 1\2 I sit and listen.  Needs to have ultra wide sweet spot and dig deep into 30hz range or below.

My 'room' is a 1650 sq ft loft with really no walls and 22ft ceilings. Its not just a box, but mostly open.  Room treatments will be an ongoing thing, but I don't want the speaker to sound bad in the interm.   Surprisingly, its actually OK and does not echo, I think due to the material used in the roof.

Anyway.  I want a speaker that first and foremost makes maximum use of these watts.  I don't want to ever think that they may sound way better with 2x or 3x the watts.   But I also don't want them to be so efficient that they will sound the same with 1 watt.  Something just right to use this amp as designed.   This may seem odd, but its required that I find the spec sweet spot here first, to manage my future upgradeitis.  In that sweet spot, I will audition as many as possible.  But I'm not sure what ohm/db that would be? Ish?? 


Used I was thinking acoustic zen creshendo, focal, legacy, tekton(??) or tannoy prestige.   Since I have so much air to move I may be leaning more to larger drivers?

I am not sure I want k horns with this amp....

Any suggestions welcome :)