Speaker used to reproduce surround channel information primarily to create ambience and sonic realism. Surround channel speakers are usually hung on a wall or ceiling to the sides of the listener or behind the listener. he most popular types of surround speakers are dipolar and bipolar speakers. These types of speakers provide a diffuse sound that tends to fill a room without creating a specific point source (the sounds seem to be coming from all around instead of from a specific pair of speakers). Dipolar and bipolar speakers feature drivers on two sides of their cabinets opposite each other. Bipolar speakers feature drivers operating in phase while dipolar speakers feature drivers operating out of phase. Dipolar speakers provide the most diffuse sound field and are certified by THX for surround channel use. Bipolar speakers fall somewhere in between the highly diffuse or spread out sound of dipolar and the localized sound of direct radiating speakers (traditional speakers that create sound from a driver on one side facing the listener). When direct radiating speakers are used as surround speakers, they provide very precise surround sound imaging. However, they tend to make themselves noticed as the listener’s ears easily detect where the sound is coming from instead of sensing an overall sonic environment. n almost all cases, surround channel speakers are fairly small in size similar to that of bookshelf speakers. Surround speakers should be full range similar to a bookshelf speaker (extending from at least 80 or 90 Hz up to 20 kHz). Most surround speakers are not called upon to recreate large amounts of bass information, but those with substantial low frequency extension tend to possess more impact and weight to their sound. urround speakers should be sonically similar to the other speakers in a surround sound system in order to present a uniform and cohesive sonic environment. The sound of a jet should not change dramatically as it moves from the front speakers overhead to the surround speakers. Surround channel speakers are an important part of recreating the movie theater experience in the home. They provide the “you are there” feel and impact not available without them.