I have two hung side-by-side. they are 3w diodes, i think epistars. One's 240w and the other 270w, i have them in about a 2.5"x 5" closet, like a pink supernova in there. If I were doing a 4x4", i'd either go 2 apollo 8's in parallel, or get 4 independent COB LED's you can hang separately to...