Cable Entry
Headphone cable entry describes whether a cable connects to one side of the headphone or separately to both earpieces.
A single-sided cable carries both audio channels through one headphone connection. A dual-sided cable divides into left and right branches, with a connection to each earcup or earpiece.
Cable Entry — Headphone Cable
The arrangement determines how the cable must fit the headphone. A single-sided design needs the correct multichannel connection at one earcup; a dual-sided design needs both left and right terminations. The amplifier-end plug does not determine how many connections are present at the headphone end.
Compare the entry arrangement together with connector dimensions, pin wiring and the intended headphone compatibility. A 3.5 mm or mini-XLR plug name alone does not tell you whether there is one plug or a pair. Single-sided and dual-sided also do not establish balanced operation. An extension without headphone-end terminations has no cable-entry arrangement of its own.