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


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 :)

Your room is kinda big. I have not listened to this speaker, but a friend who is an equipment manufacturer and has great ears loves these:

I would go with the floorstanders with 10" or larger woofers due to room size, and look into a room correction device.

"But I'm not sure what ohm/db that would be? Ish??"

So far, the listing of speakers here have a wide variety of these parameters. IMHO, the sensitivity is the main issue and would choose a speaker above 90db for 8 ohms or 93db for 4 ohms. That sensitivity specification is measured with a 2.83v input, so for an 8 ohm speaker, it's 1 watt and for a 4 ohm speaker, it's 2 watts. To make a comparison between those speakers, a 3db adjustment must be made. 

You are welcome.

I'm sure the AZ Crescendo is a fine speaker, however with the 6 ohm impedance, the sensitivity at 1 watt would be 88.5db, 1.5db less than the listed 90db. Also, recommended minimum power is 50 watts. That tells me it is somewhat power hungry and would likely be better in your space with more power than the A-S2100.