Speaker size and soundstage

It has to do with spacial cues in the recording.  I can get a huge soundstage and imaging (placement) with 2 monitors and 2 subs with the right recording, with others not so much. Room treatment and DSP to control FR, phase and delay will help achieve it more than the size of the speakers. 

2 subs
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Subs can not produce high fidelity, Subs are for HT effects,  useage ONLY, Not for music.

According to some comments it seems that Harry Potter was selling cables to some members of this forum ... I will never cease to be surprised by the capabilities that some people assign to a couple of cables.

Soundstage, breadth, depth? engineers and years of studies to understand and build systems that offer specific characteristics to the sound like those mentioned above (and the interaction with the listening room) but it turns out that all this does not really matter ... you just have to change the cables! Yes baby!!

w123ale, you have to close your eyes when you listen to remove visual ques from the equation. Tektons have a terrible image. Stay away.
There are only two sizes of sound stage, point source and line source. Line source speakers of which there are very few which are truly full range produce a large up front sound stage. Point source speakers, of which there are many produce a smaller "miniature" sound stage. 
You can adjust the situation somewhat with speaker spacing and listening position distance but if you like sitting in the first 10 rows you need to search for a line source speaker or partial line source speaker like Magnapans or any number of ESLs. The only full range line source that I know of on the market right now is the Sound Labs 845 or 945. 
Point source speakers are a dime a dozen, you have to chose your own poison.

If you have the space to pull the speakers out from the wall at least 3 or 4 ft, you might want to take a look at open baffle speakers such as this from Spatial.