{"id":1279,"date":"2026-10-31T11:09:01","date_gmt":"2026-10-31T11:09:01","guid":{"rendered":"http:\/\/lbscable.com\/en\/2026\/10\/31\/speaker-wire-polarity-which-conductor-is-positive\/"},"modified":"2026-10-31T11:09:01","modified_gmt":"2026-10-31T11:09:01","slug":"speaker-wire-polarity-which-conductor-is-positive","status":"publish","type":"post","link":"https:\/\/lbscable.com\/jp\/2026\/10\/31\/speaker-wire-polarity-which-conductor-is-positive\/","title":{"rendered":"Speaker Wire Polarity: Which Conductor Is Positive?"},"content":{"rendered":"

You have a two-core speaker cable in your hand, both conductors look the same, and the specification sheet lists colours but never says which one is +<\/strong>. Or you are on a site where the jacket print has worn off and nobody labelled the far end. This page answers the polarity question from published LBS data: how a two-core speaker cable marks its pair, what to do when the marking is gone, and what has to be agreed with the factory when a project drawing needs a specific colour or legend.<\/p>\n

It is written for installers terminating speaker runs and for distributors answering the same question from their own customers. Every specification quoted below is taken from the published LBS catalogue and the product datasheets; where a value is not published, the page says so instead of filling the gap.<\/p>\n

Short answer<\/h2>\n\n\n\n\n\n\n\n
Question<\/th>\nAnswer<\/th>\n<\/tr>\n
Which conductor is the “positive” one?<\/td>\nNeither, until you assign it. A loudspeaker signal is alternating current, so the +<\/strong> mark is the reference you keep identical at both ends of the run — not a permanent electrical polarity inside the cable.<\/td>\n<\/tr>\n
Which one goes to the red terminal?<\/td>\nThe conductor you have designated +<\/strong>. In the trade convention the red conductor is +<\/strong> and black is −<\/strong>, and amplifier and loudspeaker terminals normally follow the same colour code.<\/td>\n<\/tr>\n
Why does it matter which way round?<\/td>\nIf the pair is swapped at one end of one cabinet, that cabinet’s drivers move opposite to the others. In the shared listening area the two outputs partly cancel, and the loss is heard first in the low frequencies.<\/td>\n<\/tr>\n
How do I check a cable that is already installed?<\/td>\nContinuity test with a multimeter, or a battery “pop” test, then label both ends and record the colour pair on the drawing.<\/td>\n<\/tr>\n
What does LBS publish about core identification?<\/td>\nThe unjacketed twisted-pair range is published as standard colour combinations (with custom colour coding on request); the double-colour parallel range is published as a polarity-identified zip-cord design. For jacketed ranges, core identification is agreed on the enquiry.<\/td>\n<\/tr>\n<\/table>\n

What “positive” means on a speaker cable<\/h2>\n

The audio signal leaving an amplifier is alternating current: it swings positive and negative around zero many times a second. A cable therefore has no fixed internal polarity — nothing inside the copper is permanently “the positive wire”. What the +<\/strong> terminal describes is the reference end<\/em> of the pair: the amplifier’s +<\/strong> output is bonded to a driver’s +<\/strong> input, and the two −<\/strong> ends are bonded together.<\/p>\n

When the two loudspeakers of a stereo pair both follow that rule, both cones move outward together on a positive-going signal. When one speaker is wired the other way round, its cone moves inward while the other moves outward. This is what “out of phase” or “reverse polarity” means in practice, and it is the reason polarity is checked at every termination point on a job, not only at the amplifier rack.<\/p>\n

Two practical consequences follow. First, the colour of a conductor only tells you something if it is consistent end to end: a cable with red and black insulation is useful because red can be assigned +<\/strong> at both terminations. Second, a cable with two identical cores is still perfectly usable — it simply has to be identified by other means, which is what the rest of this page is about.<\/p>\n

How a two-core speaker cable marks its pair<\/h2>\n

There are three marking systems in common use, and most professional cable uses one of them:<\/p>\n