Most “disappeared” speakers.

In that price range new and used you have a lot of choices in vanishing speakers. I was lucky enough to find a pristine pair of Maggie 3.7, sent them back to Magnepan for a total refresh and they emerged as the lastest model the 3.7i all for less than $4K.
Just be aware that the more transparent a speaker is the more it will reveal the shortfalls in your sources and supporting equipment. 

The omega super alnico without any crossover is a nice choice for a disappearing speaker. 

With a sub and low watt single ended amp it is sublime. 

I have a set of Dahlquist DQ10s with two Dahlquist Subs, that I have upgraded here and there along the way  These speakers were always noted for their sound staging and disappearing. 

These speakers can even do sounds that can move around the room . . . even passing, in its illusion, right through your head. I bought them used back in the 80's and still have them today.

@select-hifi 

‘hole’  ?? Huh? 

Horns
single driver 
concentric driver
wall mounted
sealed box
ported box
isobaric configured
line array 
omnidirectional 
line transmission 
AMT based


I’m sure I’ve left some out

shkong78 wrote:

You can try out Magnepan LRS with generous 60 days return policy.

Planar speakers are known for disappearing act.

Boy, did I learn that when I brought home a pair of Magneplanar 1.7s in Nov. 2013. 5-1/2 years later they are more stunning than ever. I recently put on Holly Cole’s “Temptation” LP and the resolution, dynamics, and imaging were all stunningly mesmerizing. I have some Acoustic Sounds remaster/reissues that put the artists (e.g., Nat Cole, Diana Krall Trio, Count Basie, Frank Sinatra with Basie or Nelson Riddle, etc.—take your pick) right in the room.

The Maggie 1.7s combine nearly massless dipole diaphragms with 924 sq. in.  (per pair) vibrating surfaces. These are vibrating surfaces that approximate the areas of piano soundboards and the spruce tops of celli and bass viols, all with radiating patterns that approach those of the instruments themselves.