Limited soundstage between speakers

For experimental sake just move your listening chair forward until you get the soundstage you are looking for. From that position optimize your speakers forward and back from the front wall. As the speaker move forward the stage should improve but at the expense of bass. Now move back and do the same thing again except move the speakers wider. You’ll finally get to a point that you start to lose the sound stage by just optimizing the placement in your room.

After you’ve reached the best it can be in your room you can start with acoustic enhancements. Simple things like throwing a blanket over your flat screen makes a difference after you’ve optimized the room. There are lots of articles on the interweb about how to determine room interaction but for me without optimization it's hard to determine what acoustic enhancements are actually doing. 

Both my ¢s so take it for what it’s worth

+1 sonic79

99.9% of music should appear between or at the speaker.  That's just physics.  There could be room reflections causing the appearance of sounds outside the speakers but that would be unfortunate.  As mentioned, using out of phase recordings can cause a sound to appear outside the speaker span. 

Roger Waters amused to death has a few such recordings.  Try listening to that ans you should hear some sounds outside the span of the speakers. 

Jerry

99.9% of music should appear between or at the speaker.  That's just physics.  There could be room reflections causing the appearance of sounds outside the speakers but that would be unfortunate.  As mentioned, using out of phase recordings can cause a sound to appear outside the speaker span. 

Amazing that physics is not the same in 2 rooms....or perhaps physical acoustic is one thing and psycho-acoustic is another field you must consider to exist....

The timing of reflections is one of the acoustic factors with which the Ears/Brain translated sound impressions INTO standing objects located in space in the room...The distribution of the different pressure zones is another one...

The correlation between the direct TWO distinct wavefronts coming from each speaker for EACH TWO ears with a time delay and the back and lateral reflections frontwaves timing is what i used to create in my room the intimate headphone effect of a sound out of my head but incorporating me in the soundscape...(i use Helmhotz diffusers and resonators,ionizers,Schuman generators grid, and a double screen panels with many acoustic devices on it to reflect , absorb or diffuse sound in some balance....

Perhaps you must add psycho-acoustic to physical acoustic in your scientific reading agenda...

Sound waves are not ONLY "rays" coming apart from one another on or from the walls , they are also different zone pressures competing with each others.... The dynamic geography of these pressuures zones and the tiiming of reflections in this geography, determined what i listen to and interpret to be a musical instrument standing at my left or right, OUTSIDE of the speakers vertical plane location...In my room at least.... 😁😊

It is not a mere distortion, a trick coming from out of phase speakers that explain the soundscape appareance, which is NOT an illusion by the way , but a phenomenon emerging from the way the ears/brain read and interpret the speakers/room relation through the recorded information transformed in the waves of sound and ALSO the way the ears/brain read and interpret the recorded acoustic relation of the musical event play back through the room /speakers relation ....it is a double interactive acoustic event: the acoustic of the recorded album with the acoustic of your room .....

The best way for your room to disapear and let the musical playback be optimal is after being put UNDER acoustic control...If not, the recorded event will not be acoustically optimal and will stay a 2-D not differentiated object between the speakers and not a multiplicity of 3-D standing objects or musical instruments around you outside the speakers in most well recorded modern album....

The depth of the sound is not only described as imaging and soundstage in acoustic but also in the " listener envelopment " factor....

99.9% of music should appear between or at the speaker. That’s just physics.

rrm, I've been giving some thought to things that you might do to 'improve' your soundstage, but  nothing I've come up with can create the outside of your speakers soundstage which you initially indicated that you wanted to obtain. Others have discussed set up of speakers and listening position. I believe someone mentioned the Cardas system which is a good place to start, if you haven't already got a good placement of speakers and listening position determined. 

For consideration is an add on devise that has been around for a few years and has gotten good reviews. It is a Fusion FOZ. It is tubed unit which allows you to control the out of out of phase information in your recording. In older recordings (and some new ones as well) which seem to have a too centered image, albeit still stereo, by increasing the strength of the out of phase signal in mix in the recording you can get a much expanded soundstage. Wider/higher/fuller. BUT it will not create sound outside of your speakers on the plane of the speakers, but can easily fill the wall behind you speakers. The good news - it is not expensive and it sort of acts as a tubed buffer (if you want one). The bad news is it is not exceptionally transparent and works best, I think, in a tape loop. Further, by increasing the out of phase signal you do reduce some of the in phase specificity. It has a bass control as well if you need it. The unit is a bit bass rich and you might. Underwoodwally sells them if your interested. They are relatively cheap. Something to think about....or not. :-)