So it's funny after several months to come back to this thread that I started and see all of these great ideas.
What I ended up doing I am really happy with. I got 4 rock speakers from Amazon ($100 total) and wired them up (buried wire) through our laundry room into a Denon 4100w receiver. The receiver is way overkill I think, but I got it at a Goodwill auction for $420.
This setup really jams loud. It's awesome.
For future onlookers, I really struggled with which wireless option was best for the iPhone. After wrestling with Bluetooth, I ultimately decided that AirPlay was the best. This is built in to many receivers right now. Only thing is that I had to get a $20 repeater to get my signal out to my pool stronger for streaming. When I start playing music, it turns the receiver on automatically. When my friends come over, I just give them the wifi password and they can play their Spotify playlists.
Thanks for all the ideas.
- - - Updated - - -
Forgot to mention that the reason rock speakers worked really well for my project waste that I had a rock wall already in the landscape and you can't even see them.
Next step is to get a projector screen and projector.
