The Inward Triangle Speaker Rule
Never place a speaker against the house wall pointing out toward the bottom of the garden; the sound waves travel straight into neighbouring bedroom windows. Instead, place two paired portable speakers near the outer corners of your blanket zone, angled inward toward the house brick wall, raised 60 cm on wooden crates. Keep average volume around 65–72 dBA at the centre of the rug, and roll off extreme sub-bass below 60 Hz after 20:00.