Probably should chop down some of those trees to reduce reflected sound, don't you think? 
Strangely enough, not too many people have ventured into the "outside listening thing" for obvious reasons.
But I used to set up a really simple system out on my lawn/patio with a pair of DQ10 Dahlquist speakers and Citation electronics, and work all afternoon in the sun while listening to a "roomless" system.
The sonics were remarkable (no reflections)

The clarity and pureness were a "sound to behold". I did have to sit rather nearfield, but I do that anyhow.
I did keep the electronics and turntable inside the house and ran the speaker cable outside.
Symphonic works were like going to the Hollywood Bowl (which I would years later)
Man, those were the days.
