Affordable vs. ultra expensive speakers - what's the difference?

i already said that here like you...

But people are consumers not experimenters in acoustic...

They bough, they dont learn how to listen anyway, and most call that a "taste" ...

There is long debate about branded names value right now here...

And useless debates about "tweaks"...

Just to say my room cost me nothings and beat all the gear i could have upgrade to....We must learn acoustic, we dont buy it.... Because the highly tech acoustic room will cost more than any audio very costly system anyway...

basic treatment and simple controls acoustic method are simple at the basis anyway...Complex to tune it asking for time listenings experiments but nothing is more fun and rewarding....Nothing...Certainly not upgrading the gear in an empty  non treated and non controlled acoustical room......

The future of the audiophile is investing in high performance rooms first, then place technically advanced speakers inside them with wide dynamics, wide dispersion and low distortion.

I can provide some actual listening impressions to address the OP's question. I have the previous-gen Monitor Audio Silver 300s and have been quite pleased with their resolution and refinement especially at their very reasonable price of $2200. When I was auditioning DACs a year ago, I had purchased a Chord Qutest that was used both at home and taken to dealers as a consistent point of reference to compare to otther DACs. I was listening to a system at a local dealer and didn't recognize the floor standing speakers that had a trapezoidal shape. The speakers sounded fine but no better or worse than my Silver 300 speakers. As it turns out, the speakers were the then-new $18.5K Wilson SabrinaX s. (or about 9x the price of my MA Silver 300 speakers) Honestly, even at the same price, I'm not sure if I would pick my MA speakers or the Wilson speakers if I were listening blindly. One caveat is that I tend to listen at fairly moderate  volumes & perhaps one advantage of the Wilson speakers (and perhaps some other higher priced speakers) as others have mentioned is the ability to play loudly without distortion. In any case, that's not an attribute that is important to me.

I have heard some more expensive speakers that do pique my interest. Before getting the Silver 300s, I heard a pair of used Monitor Audio Gold 200s with a pleated AMT tweeter at about the same price. Those clearly had a clearer and more resolving high frequency response as well as a level of sweetness to the sound that was clearly better than that of the Silver 300's sound.

Many years ago, I heard a pair of well set up Martin Logan CLS II speakers. I think they now retail for $35k. The speed and immediacy of those speakers was eye-opening & I still remember how they sound many years later. BUT, I don't' really want a pair of giant "screens" in my room.

Finally, as others have mentioned, without a decent sized room with acoustic issues sorted out, I don't think there's any point in getting ultra expensive speakers.  I see pictures of people with huge floorstanding speakers costing $10k, 20k, 30k or more in 200 square foot rooms such as you might find in a New York City apartment. That just seems like an outright waste of money to me. There just isn't enough distance in some of those rooms to propagate the low frequencies that some speakers can easily produce. It's much better in my opinion to get a small precise standmount and accept that as the best fit for that size of room.

The items have different specs, dimensions and prices and have a different sound signature.

Is the question you are asking is the difference significant?  And is it worth the cost difference?

If that's the question you have to answer that for yourself by listening and then determining which is the most effective use of your money.

@mahgister 

Yes I'm being a PTA but it's been bugging me so here goes.

What is your definition of acoustic?

If you are using it as a noun there's an "s" on the end.

ADJECTIVE

1. relating to sound or the sense of hearing.
   "dogs have a much greater acoustic range than humans"

2. (of popular music or musical instruments) not having electrical amplification.
   "a sad, gentle acoustic ballad" · 

NOUN

1. (acoustics)

   the properties or qualities of a room or building that determine how sound is transmitted in it.
   "Symphony Hall has perfect acoustics"

2. (acoustics)

   the branch of physics concerned with the properties of sound.
   "Tyndall lectured on acoustics"

3. a musical instrument without electrical amplification, typically a guitar.
   "these German-made acoustics are a pleasure to play"

or I'm just being an Ahole but I may not be truly understanding the philosophy your trying to convey with the term.

Acoustic: physical science...

And psycho-acoustic which is the science relating physical acoustic to perception evaluation and experiments... Correlation in listening experiments between objective factors in acoustic measures or with acoustic devices ( panels or any other devices) and the subjective experience...

--- I used passive material treatment: I experimented with balance between reflective and absorbing and diffusive characteristic of the room...

--- I used mechanical activated control of the room using Helmholtz method: H. resonators and H. diffusers... This is like a finely tunable grid set of bottles and tubes mechanically adjustable distributed at some key location in my dedicated room...

My philosophy is based on the scientific fact that we do not listen to the gear but to the system/room ...

My method of tuning the room consist in transforming the room accordingly to my speakers needs and to my own ears timbre perceptive ability and to other acoustical cues perceptive experience...( soundstage,imaging,dynamic,listener envelopment etc)

My motto is:

No upgrade could ever give the powerful transformation given by the controls over the three main dimensions related to any audio working system: mechanical, electrical and acoustical...

Dont upgrade anything BEFORE embedding it rightfully...

Is not clear?

or I’m just being an Ahole but I may not be truly understanding the philosophy your trying to convey with the term.