Rear effects channels determine the envelopment you experience with all multichannel recordings. However, hearing the surround channel location rather than the surround effects undermines the spatial realism possible with today’s movie soundtracks and music recordings. Adopted by THX in 1990 as the de facto standard for surround playback, dipoles effectively reproduce all of the effects content in a diffuse and airy way. The IW SR30THX is based on the world’s first THX Ultra2 certified surround speaker, setting a new benchmark for high-performance dipoles with its innovative design. More than mounting flush to a wall or ceiling and virtually disappearing, it is a full range surround that easily exceeds the 80Hz THX standard. Much like an array of movie theater surround speakers, its figure 8 pattern, with a wide null directed at the listeners, ensures a very diffuse, non-localized sound field to a very large listening area. Its novel driver configuration gives enhanced dipole performance with optimum polar response. Two outward firing “Directed Power” tweeters make up the high frequency part of the dipole radiation. An edge-mounted midrange extends dipole performance down to 400Hz. As for bass, the IW SR30THX’s 6 1/ 2” woofer includes its own acoustic suspension enclosure, assuring the bass extension and output necessary to enjoy the demands of Dolby Digital (AC-3) and DTS recordings.