Audiophile Goal Perfect Center Image

Push the mono button on your preamp. How is the central image now?

I was under the impression line array speakers need to be a minimum of 15 feet or more apart or else phase issues come into play.  Many listening rooms don't have the space for the proper stereo spread.  In your typical large home listening room this one speaker could fill every inch, two would probably have been overkill or counterproductive??

Music is recorded/mixed in stereo and needs to be reproduced that way with two speakers.  That the one Wisdom speaker sounded good, while maybe surprising, is irrelevant — only real question is how much better it would’ve sounded with two line-array speakers and reproducing what the recording engineer truly intended.  BTW, I’m a huge fan of line-array speakers (Nola, Genelec, etc.) and understand why even one would sound pretty good.  

I agree that particular track is incredibly recorded, but I did listen to others and I could swear there were speakers all over the room turned on. I actually checked. No it was this ONE array/subwoofers filling the room 180 degrees! I think at lower volumes this affect wasn’t as dramatic, but at volumes say 85-90dB+ the sound was very live sounding and enveloping.

Yes, there is much more to an 'in the room' soundstage than the center image.

To fully understand your question we must read about the relation between a room soundfield translating a recorded "wall of sound" for example in our speakers/room for our ears...

This acoustic translation will be improved if we take advantage of our TWO ears and TWO speakers in a specific acoustic way...This is acoustic passive treatment and mechanical acoustic control of a room...

Timbre perception, imaging, dynamic, listener envelopment/sound source width ratio, soundstage are all acoustic cues which are captured in some specific way for each recording and which ask to be translated by our 2 speakers in a specific room acoustic content for our different two " ears "...

A live concert CANNOT be reproduced identically, the recording process is a trade-off set of choices already, and your own speakers/room/ears is another set of trade-off choices...

A live recorded concert can be TRANSLATED in your room /speakers/ ears acoustic language...No identical reproduction is possible because already BEFORE the recording microphones placement, each listener at this concert will perceive the same concert differently...

And by the way in a controlled room acoustically speaking the sound is not CONFINED to the plane between the speakers when played back from many recording translation choices by the recording engineer... In an uncontrolled room the soundfield is often  captive between most speakers all the time...

I know we have two ears but when I went to a live concert recently the sound was coming from that one musician, not from the left or right 10-15 feet apart like speakers are placed. Why do we need two speakers if the goal is to make them sound like they are coming from one source?

What I think you are hearing is a deliberate result of the choices made by the record producer, often called the "wall-of-sound." 

However it is not adopted by all genres and all recordings.

I concur with ghdprentice..

The center image is the very simplist of things which almost any speakers can achieve easily. That is the starting point for imaging.. well after correct tonal balance and a few other things. Then there is soundstage width (beyond the speakers) and depth from the speakers many feet behind… beyond the wall for good speakers. A good system can reproduce sounds behind you like qsound allows.