You have to question the need for ‘weatherized’ portable speakers if your keyboard isn’t equally weatherproofed. And battery powered..!

My experience with small systems like this, especially in outdoor settings, is that at anything higher than background music levels, they generally need to be paired with a powered sub, and there goes your battery powered weatherproof concept. Indoors, yes, they probably work as well as things like the QSC K8’s, but even there you only have a certain volume level before the ‘deep mode’ stuff starts to be non-linear.

You have to remember, outdoors you seldom get a bunch of walls, ceilings etc. to focus the sound, and drop off is much more pronounced than indoors. And the low end drops off sooner than the highs unless you place them flat on the ground, and that’s not good for getting the mids and highs to project. Damned if you do, damned if you don’t…

At $1500 or so a pair, it’s probably worth asking yourself how many gigs you do with zero access to mains power and a high probability of rain, and whether a power bank wouldn’t be a cheaper solution to power your existing gear.