Between the amplifier and the passive speakers, the cable carries the entire music signal, including bass, and delivers the current required by the drivers. This five-metre coil of Opéra cable combines two 2.5 mm² conductors made of tinned oxygen-free copper, within a transparent sheath bearing markings. It is enough to connect a pair of speakers positioned on either side of a hi-fi stand, cutting each length to suit the room.
Each conductor brings together 224 copper strands measuring 0.12 mm in diameter, arranged in seven braids of 32 strands. This copper is OFC (oxygen-free copper), with a purity of 99.99%: its manufacturing process reduces the metal’s oxygen content, and therefore the impurities lodged between its constituent crystals. The copper is then covered with a thin layer of tin. This tinning protects it from oxidation, the dark film that gradually spreads over a bare copper wire exposed to air, starting at the stripped ends where the cable meets the terminals. A conductor that stays clean maintains solid electrical contact over the years, and the tin also makes soldering easier if you choose to fit this type of connector. The stranded construction makes the cable flexible: it follows a skirting board or bends around the corner of a piece of furniture without resistance.
The cross-section refers to the copper surface area of each conductor. The larger it is, the lower the cable’s electrical resistance, and the less energy it takes from the signal on its way from the amplifier to the speaker. With 2.5 mm², a 2.5 m connection (equivalent to 5 m of copper counting the signal’s outward and return paths) has a resistance of around 0.035 ohm, a negligible value compared with the 4 to 8 ohm impedance of a typical speaker. The amplifier maintains control over the movements of the bass cone, and the tin layer, slightly less conductive than copper, makes no difference at this scale. This cross-section remains comfortably adequate for lengths of up to around fifteen metres with 4-ohm speakers. For longer distances, or speakers with very high current demands, Opéra cable is available in 4 mm².
The smoked transparent PVC sheath insulates the two conductors, provides mechanical protection and leaves the copper visible, allowing you to check the condition of the strands at a glance after cutting. It carries three types of markings. The polarity marking distinguishes the positive conductor from the negative, so that each red amplifier terminal can be connected to the red speaker terminal. If just one of the two speakers is connected the wrong way round, its cone moves backwards when the other moves forwards: the bass partially cancels out and the stereo image loses definition. Length markings help you cut two identical sections without a tape measure. Finally, arrows indicate the installation direction, from the amplifier towards the speakers, determined by the structure and braiding of the strands.
The coil contains five metres of two-conductor cable, giving two 2.5 m sections when cut in half, minus the few centimetres used for stripping. This length suits installations where the amplifier sits between the two speakers: a hi-fi system on a low cabinet, bookshelf speakers on either side of a shelf, or a small desktop system. The cable is suitable for all passive speakers, both floorstanding and bookshelf models, in stereo systems or for the front and centre channels in a home cinema system. The rear speakers in a multichannel system, often positioned far from the amplifier, require more cable, available in 10 and 100 m coils or cut to length by the metre. For connections, the stripped bare wire can be clamped directly into screw terminals, or fitted with Triangle BP450 banana plugs, which are more convenient if you frequently disconnect the speakers.
About one centimetre is enough for most screw terminals. Once the insulation has been removed, twist the strands between your fingers to form a compact bundle, then tighten it in the terminal. Check that no stray strands stick out: a single copper wire touching the neighbouring terminal creates a short circuit, which is dangerous for the amplifier.
No. Bi-wiring connects the bass and treble sections of a speaker equipped with dual binding posts separately, requiring two cables per speaker, or four lengths for a pair. Five metres then leaves only about 1.20 m per length. For bi-wiring, the 10 m reel is the right starting point.
The signal travels in both directions and the installation works. The arrows indicate the recommended installation direction, and following it requires no extra effort: simply unroll the spool starting from the amplifier. The marking that matters most for sound remains the polarity marking.
An active speaker has its own built-in amplifier and receives a line-level signal via an RCA, XLR or digital cable, not a speaker cable. Only active pairs in which one speaker powers the other via screw terminals use this type of connection between the two speakers. Similarly, a subwoofer is usually connected via RCA; the Opéra cable is only used if the subwoofer has high-level inputs connected to the amplifier’s speaker outputs.
Tinning significantly slows oxidation without making copper completely impervious to deterioration, especially in a damp room. If the end of a cable has tarnished after several years, simply cut off two or three centimetres and strip it again: the copper is intact beneath the sheath. Banana plugs provide lasting protection for the ends and avoid the need for this operation.
The 2.5 mm² Opéra cable is available in 5, 10 and 100 m reels, cut to length by the metre, and as a pair of pre-assembled 2 × 2.5 m cables fitted with banana plugs, ready to connect. The 4 mm² version is available in a 100 m reel and cut to length, for long distances or large concealed installations.
It is not an electrical requirement: with this cable cross-section, a difference of a few dozen centimetres makes no audible difference. Equal lengths still simplify routing and make for a tidier installation. If one speaker is significantly farther away than the other, cut each length to the required size rather than leaving an unnecessary loop of cable behind the furniture.
Based on reviews from customers who purchased this product, summarised by AI
Steve
Nothing to complain about. Excellent-quality cable, truly robust and visually more discreet than other commercially available cables (entirely grey in colour)
Comment from 6 August 2026 — Experience from 20 July 2026
Nicolas
cable matching the description
Comment from 15 February 2026 — Experience from 23 January 2026
Philippe
Excellent cable quality
Comment from 12 November 2025 — Experience from 31 October 2025
