Bi-wiring is the use of two runs of speaker cable per channel between the amplifier and speaker. Tri-wiring is similarly the use of three runs of speaker cable per channel, but you will require a three way loudspeaker and three rear pairs of terminals per speaker to achieve this. Some people advocate that separating the signal paths aids the retrieval of fine detail. However, the evidence is far from conclusive. If you intend to bi-wire your two way speakers, or tri-wire your three way speakers ensure the metal links on the back-panel have been removed. If you wish to bi-wire our three way speakers, so the tweeters and mids are served by one set of cables and the woofers by a separate set of cables, remove the bottom link, but retain the top one.