Wanna take it to the next level? Buy MORE speakers!

I believe the first picture is from Clockwork Orange.

I have over 20 years in modding the weak point in most loudspeakers ,many mfg use average parts at best , I almost alway upgrade my own the same values inside 

just far bette quality , go to humble homemade hifi capacitor test , 

Jantzen foil wax paper inductors path audio resistors , or Mundorf ultra resistors .

connectors many use cheap gold over brass,WBT Copper far better conductor is preferred ,

the Xover it’s the brain 🧠 or ♥️ of your speaker just look up the above Tony Gee is the man and has helped me ,. I just felt it needed to be said . And can give you over a 10% improvement  
 

Driver quality is far and away the biggest contributor to speaker performance, followed by cabinet construction. Crossover component quality is third at most, presuming the crossover circuit is otherwise competently designed. 
 

I get why some enjoy experimenting with crossover components but they are not the weak link in the majority of speakers. Most often the drivers are what are mediocre. 
 

Driver quality is far and away the biggest contributor to speaker performance, followed by cabinet construction. Crossover component quality is third at most, presuming the crossover circuit is otherwise competently designed. 

I get why some enjoy experimenting with crossover components but they are not the weak link in the majority of speakers. Most often the drivers are what are mediocre. 

+1 @helomech 

I have experimented with a stash of crossover components from GR research. 400 to 600 dollars at most (or say under a 1000 dollars)  in crossover component upgrades gets the fidelity close to max (ime) and diminishing returns hit like a wall thereafter, as you go up in price. But, a crappy driver from a manufacturer is a crappy driver and there's no fixing that...

Manufacturers have cheaped out on crossover components so badly that the illusion of crossover component quality being the main culprit exists.

If I want SPLs I have four matching Vandersteen 2 in my living room. These are driven by a single McIntosh 2200 amplifier. The rear pair are wired in reverse polarity to the front pair.

If I want laser-precise imaging and detail I have a pair of Sourcepoint 8 hooked up to the same amplifier via a switchbox.

Honestly, most of the sit down listening is done with the Sourcepoint 8. They are slightly harder and hotter sounding w/o EQ but you do get that holographic imaging with them as a 2-way dual concentric.

I also have two matching 10" Klipsch subs for that earthquake-under-my-seat effect.

…it's something.......different…

+1 @mikelavigne -  2 channel and surround are different

in my main 2channel, I barely manage to finance my Vimberg Mino D.  If I had to pay for more speakers, then sonic quality is reduced.  My Vimberg Mino D might be my end game main speakers.

in my flea watt 2 channel, I’m using the Volti Rival 100dB to explore tube magic starting with SET amps.  How can this translate to a surround system?

Both speaker manufacturers don’t offer “surround” components.

There is an alternative that I “subjectively” would be satisfied with, but it’s beyond my budget - Magico S Series.

How about additional amplifiers expenses….

Maybe someday I’ll build a quality surround system, but not at the expense of 2 channel sonics.