"I am 4ft from speaker L, 4ft from speaker R, so 4ft between speakers... 2 * 24" monitor =44" width.. so defining sweetspot does not preclude 2 monitors :)" No, it doesn't but it does add a big 44" reflective surface right in the middle where it mucks up your sound.
I'm also guessing that your speaker cones, are closer to 60", center to center, apart.
If you go too wide you loose the center focus... the important part... and you have to imagine it.
If you have a big panel of *reflector* in between the speakers... you are not just listening to your speakers... you're listening to comb filtered mush.
Heck there may not even be a sweet spot. ;-)
I've always thought that setting a room up to sound good is a good priority.
That's why I retired my second DAW monitor right after I tried working with one.
I have a couple multi monitor video and graphics set ups but I go single monitor for sound cause the sound is the most important part about sound.
I've mentioned this a few times here at the forum... but many people seem to have differing priorities.
best regards,
mike