Each of the jacks may be used as an input or a through connection. Speakon® connectors are recognized as the standard for professional installations, assuring a secure, permanent connection that won't corrode, vibrate loose or be easily tampered with. The 1/4" jacks are convenient. However, the Speakon® jacks are recommended when using power amplifiers over 150 watts, for permanent installations, or for the first enclosure among a number of daisy chained enclosures. Speakon® to 1/4" Wiring Dia