speaker cable polarity standard

[Pbassred]

There must be a standard way of marking cables. For instance:-
red & white - red is +ve
Black and white -er........
both black with a white stripe?
both white with a black stripe?

and if my amp has an XLR out, is +ve ........ pin 2 or 3?

Yes I know its an AC anway but for the purpose of phasing............

[Samuel Jayaraj]

In an XLR 1 is gnd. 2 is + and 3 -. When you use an XLR as a two wire connector, usually you will find 1 and 3 shorted. But in your case, it is quite possible that 2 and 3 are + and - respectively and 1 is shield that is connected to body/chassis at one end (usually Source end) and left floating at the Load end.

[Pbassred]

Same as signal cable then.
and the colours?

[Centauri]

In an XLR 1 is gnd. 2 is + and 3 -. When you use an XLR as a two wire connector, usually you will find 1 and 3 shorted.

Beware !!! For speaker outputs, pin 3 hot is commonly used. Bose usually use pin 2. Best suggestion is DO NOT short any pins of XLR plug together. Pin 1 will always be gnd - as far as + goes, check inside the amp.

Cheers

[Pbassred]

Just ripped open my amp. Pin 2 is hot. All the pin 1s are commoned up. .................................. which rules out running in bridge mode!