Unless you are Pink Floyd, or... going for the "PF we're gonna blow your mind" effect..... Mono works best. Especially in nursing homes and 99% of all other venues.

Back in the day we ran a system and mixer totally capable of handling stereo.

From the board to the amps and speakers, we had the capability. However.... We never ran anything in stereo. Main reason is, if you do, you risk having parts of your audience miss parts of the music due to their seating location. If they are sitting on one side or the other, and are directly in front of a speaker....and you're running a true stereo mix, they will miss the stuff from the other side.

Aside from Pink Floyd, most of the bands I've seen appeared to have mono mixes. At a Trisha Yearwood concert, we had seats up front and 3 rows back but directly in front of the stage speakers. I don't recall thinking that I couldn't hear the mix well. I heard everything nicely and for it's proximity to the speakers, at a very comfortable volume level.

You can find my music at:
www.herbhartley.com
Add nothing that adds nothing to the music.
You can make excuses or you can make progress but not both.

The magic you are looking for is in the work you are avoiding.