This is the Audiopile NL8-2NL4C breakout cable. This adapter cable can be used to split an 8 conductor speaker cable into 2 separate 4 conductor speaker cables. The standard configuration splitter cable is built using a Neutrik NL8FC Speakon connector on one end tied to two, 5 foot, 4 conductor cable whips each terminated with a Neutrik NL4FX Speakon cord end. The whips are made using EWI NNT-1410B cable which is a 4 conductor 13 gauge speaker cable. These breakout cables are assembled to specification here at Audiopile in Farmington Washington.
The standard pin-out configuration of this cable is as follows: