of, noting, or pertaining to the recording and reproduction of sound over four separate transmission or direct reproduction channels instead of the customary two of the stereo system: a quadraphonic recording.
quad·ra·phon·ic also quad·ri·phon·ic (kwŏd'rə-fŏn'ĭk) adj. Of or for a four-channel sound system in which speakers are positioned at all four corners of the listening space, reproducing signals that are independent of each other. qua·draph'o·ny (kwŏ-drāf'ə-nē) n.