Weatherproof speaker drivers

For backyard music I bought cheap car speakers. I power them with a cheap 4 x 50 watt car stereo. Last year I added a dual 12" car sub. Neighbour says it can get a little loud sometimes. I have replaced some of the speakers over the last 22 years due to squirrels etc.
 
Rain and splash? Boat shops.

THIS is where the locals buy their lobster winches and trap-exits, but I'm sure boat-sound speakers are about the same any place you can have a boat.

"Good"? Depends what you are drinking, doesn't it?
 
PA drivers which withstand outdoor conditions can be found easily.

Or take a look at 'marine' item supplier. To amplify your next party on the deck of your yacht, there is dedicated 'water/weatherproof' line of loudspeakers/drivers.