Last month I upgraded the speakers on my USA spec 2022 R1250RT to a pair from Focal and though it is quite an easy job - wanted to share my experience and maybe save someone the learning curve. The model I chose was the Focal IC BMW 100, which is a plug-n-play unit with the stock speaker. Note: there is a model quite similar in name but with an L at the end (100L) which have a cushion that would cause fitment problems on the RT, so just get the plain 100. These are available from retailers in the States for typically $400. I bought mine from a reputable eastern European vendor on eBay for $208 including shipping. Note: these speakers are not labeled as waterproof but their construction is as good or better than the stock units - meaning the polyglass woofer is unlikely to be affected by moisture and the aluminum/magnesium tweeter should also be water resistant. Also note that the BMW cover has a membrane that will keep most water out of the speaker housing.
Here are the installation steps.
1) Remove the speaker grill by removing two torx screws at the bottom of the cover (red arrows in first photo). Once removed, pull the grill from the bottom out and lift up - you need to pop out three press fit latches (green arrows in second photo).
2) Remove the stock speaker by removing the three torx screws that hold it in (yellow arrows in third photo). Once the screws are removed, carefully unplug the two connectors with the speaker wires. One of these pairs (the red/purple on my bike) is the wiring for the stock woofer and the second pair (orange/black on my bike) is for the stock tweeter. Since the Focal has a combined woofer/tweeter, leave the orange/black connector tucked back in the speaker housing. Now is a good time to check the captive nuts for the grill to be sure they are still aligned properly (red arrows in third photo). Note: you can remove the speaker box by loosening three rubber-expansion torx screws and unplugging the wiring connector at the lower inner side of the box, but it is not necessary. I removed one to figure out how best to eliminate the stock tweeter, which is glued into the speaker box - so I just left it unplugged.
3) Plug the speaker wiring connector in to either of the connectors on the Focal speaker. Install the speaker with the three torx head screws.
4) Reattach the speaker grill by placing the pressure fit plugs into their respective sockets and press them in gently but firmly - when positioned correctly you feel a solid "click" when they are seated. Secure the cover with the two torx screws.
As for the performance of these speakers - I have taken a few trips with them and find they produce reasonable sound in the cockpit at lower volume levels, meaning you are less likely to bother anyone else on the road if that's a priority. There is also less distortion than the stock. Some have said this is a 20% improvement over the stock speakers - I would go further and say a big improvement in sound quality and matches the higher output of the amp in the 21/22 model.