Your project sounds wonderful. With all of those things going into your yard you should decide if the sound will be "on" at every location or if you will be switching to a location.....one or more at a time.
Here are some thoughts.
1. Select an amplifier sufficiently large enough to power ALL speakers at once, in case you might wish to do that. (Think party) The power required will depend upon the efficiency of your speakers and the cable (wire) loss to the speaker location. You may wish to use transformers to raise the impedance before it enters the cable (wire) to the speaker (to reduce the effects of copper loss), and then you will need one on the speaker end of the wire to reduce it back to the 4 to 16 ohm speaker impedance.
2. How large should the speaker wires be? That depends, 16 or 18 AWG works fine for most runs around the home, however you are going outside and we do not know how far, perhaps #12 or 14 AWG would be better (12 is larger and will cost more).
3. All locations should have their own volume control. This is difficult at high power, since most remote volume controls are built for a few watts. (see 4)
4. You may wish to use "amplified" speakers at these remote locations. These contain an audio amplifier with volume control in the speaker box and require 120VAC GFI outlet. Wire loss will not be as critical with amplified speakers and some amplified speakers are "wireless". They just require an outlet. You must decide if the audio quality of wireless speakers meets your needs.
5. You may wish artificial "rocks" for one location, underwater speakers for the pool and/or the spa and attractive boxes for another location.
6. A receiver/amplifier with a solid 100 watts RMS per channel is the minimum you would want (unless you have amplified speakers) and if you like loud music on the tennis court, I would suggest more power.......depending on the neighbors. More than two 100 watt audio channels might be helpful for driving a large number of speakers.
7. Several companies make a remote control for your electronics. Panasonic comes to mind. The wall mounted remote allows to select CD, radio or other source, change stations or music tracks, set volumes and turn speaker locations on/off. One of these "hard wired" remotes could be mounted at each location in a weather proof box.
When you run speaker and/or remote wires in your yard, be sure to include two sets of cat 5 (4 or 5 pair) telephone wire for computer networking and phone lines. Consider also "good double shielded" coax like RG-6 for a TV near the spa or other areas. think "Game Time", soaps, MTV, movies while in the spa, etc. I would bury these low voltage lines in PVC conduit to protect them. I know that you could buy direct burial cable, but an accidental shovel or pinhole leak will allow moisture to contaminate the wires and shorten or end their life.
7. This seems like a job for a professional. You are spending so much money making your yard a paradise, why not invest a little more to do your sound system correctly.
I am building all but the tennis court at my home. We have equestrian property, so it's a riding arena rather than a tennis court. I have chosen to "hard wire" my speaker locations. My phone system is six line with a KSU, so we use flat 4 conductor ribbon (wire) from each location (extension) back to the KSU. I still will be running the Cat 5 to my outside locations for "future" use. My phone system has a "paging" and "door bell answer", so we will be able to enjoy those functions poolside.
Good luck with your project, let us know what you decided.
Terry
