The struggle continues: single versus dual speakers; dipoles versus monopoles. Lightsabers swirl all around, machines explode to the side, and lasers come from directly behind you. If you saw The Phantom Menace in a Dolby Digital Surround EX-equipped theater, you heard one of the more spatially realistic soundtracks recorded to date. Now, that same technology has entered the home market under the moniker THX Surround EX (non-THX-certified products might refer to a similar process as 6.1), and a familiar question returns to haunt us: Should you use dipole or monopole (also known as direct-radiating) loudspeakers for the back channel? This time around, the question comes with a new twist: Should you use one or two speakers for this channel? Willing to conquer any challenge and answer any question, we at Home Theater took it upon ourselves to test various speaker configurations. After describing the process itself and the advantages and disadvantages of dipole and monopole speakers, we'll let you know what our panel of judges thought of the various options.