It is hard to find reviews of these and most seem like junk. Monoprice does a budget set for $83, but Sound and Vision just did a review set:
We really liked the Niles OS5.5, and we thought the Definitive Technology AW5500 and the Klipsch AW-525 were both pretty good. Review: Outdoor Speakers | Sound and Vision Magazine
So, for not very much, you can get a nice sounding set of outdoor speakers:
- Niles OS5.5 Black (Pr) 5 Inch 2-Way High Performance Indoor Outdoor Speakers.. These were the top rated ones at $220
- Definitive Technology AW 5500 Outdoor Speaker (Single, White). These a bit cheaper and wall mounted at $170 a pair.