Many use diect radiating instead of Di-pole speakers, some even run these diect speakers out of phase (reverse wires on speakers) to create the Di-pole sound, Di-pole surround speakers are wired out of phase from factory). I own B&W on wall surrounds that with a flick of a switch you can flip them in and out of Di-pole...........I strongly prefer Di-pole sound as it makes them sound much more diffuse and harder to localize, and that makes for the best experience..