Limited soundstage between speakers

Ultimately I think it is recording dependent. I've heard tracks extend beyond the speaker boundaries, so my system is capable of it. Most tracks are within the speaker boundaries, however.

In my experience, it is a combination of three things that have been mentioned. Recording,speaker placement,and acoustic treatment.  However, as important as these things are,for me,speaker placement was the most important factor.  

Each room has a geometry, a form and a size, and a topology : some openings like doors and windows, and each room has an acoustic content with various properties: a wood furniture dont work acoustically like a rug or a piles of books etc...

Speakers placement so important it is , is secondary to mechanical room control...

Because you can modify the room pressure zone distribution for example with Helmholtz resonators and diffusers and compensate for the geometry and topology of the room and for his acoustic content and even compensate for the speakers needs and the room itself, all of which problems can never be solved by repeating the common place fact about the importance of speakers placement...

Speaker placement is not enough, it is only the FIRST step, the second is passive treatment, and third and the most important for small room , mechanical control....

However, as important as these things are,for me,speaker placement was the most important factor.

Typically a major factor is the toe in of the speakers and distance between them. Certainly it is speaker dependent. Assuming a good stereo recording.

Are your speakers in an equilateral triable with you seat. How big is that triangle? If too big it can’t support a stable central image. Then start with you speakers pointed to cross 18” behind your head. Then slowly decrease the angle… at some point they should maintain a good central image and the sound field beyond speakers.

My speakers are known for their ability to disappear. But they did not at first. Toe in was to be behind my head. But turned out to work with no toe in.

Also speaker distance from wall (also effects image depth)

Too much reflection from behind speakers.

+1 sonic79