I mean from a frequency response perspective. Aren't all PAs FRFR as are monitor speakers? What's the difference between them?
That's what I figured when I was looking to go powered or unpowered. Glad I went powered. Much more versatile.Most cabs these days are full range. If a cab is full range the main difference between a monitor and a main can be in the desired throw (distance). I suspect Mr. Hammer can provide a more scientific reply.
The vast majority of cabinets I see these days can be used either as mains or monitors.
In fact, I haven't used a passive crossover based three or four way system in several years. It's all line array or basic full range active bins these days.