The backyard has two zones. One of them is here from previous owner, which are those old Bose green cylinder speakers that can handle 50w continuous each. The second zone are the Klipsch outdoor rock speakers https://www.amazon.com/gp/product/B001DZJPMA/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
See the thread where I post about that setup. Using GPIO1 to Turn On Amps & Power Supplies, Turn Off When No Music