Inline couplers for joining speaker leads back to back, currently the Neutrik NL4MMX, which links two speakON cable connectors into one longer run with all four poles passed straight through, so it works across single, bi-amp and bridged wiring without rearranging conductors. It accepts both 2-pole and 4-pole cable ends, carries 15 A continuous per contact and is rated for more than 5,000 mating cycles, with the latching design holding both sides so a joined run cannot be pulled apart by cable tension. Fitted using its second lock it stays semi-permanently on one lead, effectively making that cable male-ended.

A coupler is still a field fix rather than a design choice: keep joins off walkways and dress them flat to the floor or truss, and if a venue always needs the longer distance, make up the right length and return the coupler to the spares box.