Cross-section against length is a real specification with a right answer. Everything sold above that — exotic metals, directional arrows, elaborate braiding — is construction and packaging.
What actually matters
Resistance, which falls with cross-section and rises with length. A thin cable on a long run wastes a measurable fraction of the amplifier’s output and slightly changes the damping the speaker sees. A cable of adequate cross-section does not.
The rule of thumb
1.5 mm² for runs up to a few metres, 2.5 mm² for long runs or 4-ohm speakers. Both runs the same length, even when one speaker is closer — it costs a couple of metres of cable and removes an argument you will otherwise have with yourself.
The one thing worth paying for
Connectors, and only for convenience and reliability. A banana plug that clamps rather than crimps makes a better connection than bare wire twisted into a binding post, and it stays that way when the furniture moves.
The specification that is not optional
A fire rating, for anything inside a wall. Ordinary PVC-sheathed cable is not permitted in a cavity under most European building rules, and that is a regulatory requirement rather than an audio preference.
Questions people actually ask
What cross-section should I use?
1.5 mm² is ample for ordinary runs; 2.5 mm² for long runs or low-impedance speakers. Beyond that, the resistance saved is a fraction of what the speaker itself presents, and the audible difference is not something this site will claim.
Is copper-clad aluminium a problem?
It has higher resistance than pure copper for the same diameter, so a CCA cable sold on its thickness is not equivalent to a copper one of the same gauge. Where the conductor material is stated, it is worth reading; where it is not, thickness alone does not settle it.
Last reviewed 4 September 2026