Originally Posted by echoesian
Seems like a lot of peoples here are using direct monopoles instead of bipoles/dipoles....
Many a religious war has been waged on this topic. Search and ye shall find.
As in most things, it comes down to a matter of taste...or what review/article/thread you read when first discovering this addiction. ;-) Food for thought, movie/music soundtracks are mixed in studios with 5/7 identical monopole monitors equidistant from and aimed directly at the sweet spot.
Bipoles and dipoles are very different creatures, not similar/interchangeable as your "/" would suggest. Bipoles radiate sound as two monopoles placed back to back. Dipoles are wired to radiate their sound 180° out of phase between the front and back driver to cancel any direct sound from reaching a listener sitting on the axis between the driver faces.
My personal opinion as someone who's been in this hobby for 20ish years:
Dipoles were born of THX's efforts to bring the home theater sound home, especially the spaciouness of a big theater's acoustics and their multiple surround speaker arrays. This was back in the day of Dolby ProLogic when there were really only 2 discrete audio tracks and the surround signal was a derived mono source. This derived channel was also bandwidth limited. Dipoles, along with THX decorrelation, helped diffuse that mono signal to reduce/elminate the "in your head" sound of dual mono surround speakers. I think Dolby may have even bought into this recommendation at some point as Dolby and THX worked together quite a bit to advance the movie reproduction experience. Most speaker makers introduced dipole surrounds during this period, whether they offered THX packages or not.
Fast forward to the era of 5 discrete full range channels made possible by the Dolby Digital or DTS codecs. Suddenly, a mixer wasn't limited to putting environmental sounds in the rear...wind, rain, traffic, that sort of thing. Now, you could reproduce 5 part harmony with a different voice in each channel if you wanted with no bleeding of the signal from one channel to the next. That jet could come in over your left shoulder going toward the right corner of the room, bank across the front stage, and then zoom back out over your right shoulder. Dipoles, by design, don't produce the pinpoint imaging needed for some of these acoustic tricks that we love so much. If you look at their websites, both Dolby and DTS currently show monopoles in the side and rear surround positions while THX still shows dipoles in the side position.
As an aside, I don't recall bipoles ever getting major consideration for surround locations. DefTech and Mirage were probably the biggest proponents (that I can remember), but their speakers were bipole before the surround movement ever started. M&K had a tripole at one point...it was a three faced speaker with a switch for mono/bi/di pole operation. Seems one or two other brands may have tried the switchable idea for either mono/di or bi/di operation...just goes to show you how much agreement there is over which is better.