Mercury Hi-Flex LSZH Speaker Cable 2 x 2.5mm² Purple - 100m Reel

The Mercury Hi-Flex is a 2-core speaker cable with 2.5mm² cross-sectional area per core, supplied on a 100m reel with a purple LSZH (Low Smoke Zero Halogen) outer sheath. Each core uses a hybrid conductor construction of 39 strands of 0.2mm oxygen-free copper combined with 40 strands of 0.2mm copper-clad aluminium, giving a balance of conductivity and weight. The cable is rated for 14A continuous current and suits installations running multiple speakers from centralised amplifiers.

Designed for PA systems, distributed audio in commercial buildings, live event setups and permanent installations in venues, the LSZH sheath meets fire safety requirements in public spaces by limiting toxic smoke and halogen emissions during a fire. The double-insulated construction protects the conductors from abrasion and mechanical stress during installation behind walls, through cable trays, or in temporary outdoor rigging. The 10mm diameter keeps the cable flexible enough for routing through tight turns while maintaining physical robustness.

The purple outer sheath provides a visual identifier for speaker runs, making it easier to distinguish from mains power cables, DMX or network cabling on the same rack or tray. The 100m reel format reduces the number of joins needed in large installations and suits both cut-to-length work and continuous runs between distribution points. The hybrid OFC/CCA conductor keeps copper cost down without sacrificing signal quality for typical speaker cable distances under 50m per run.

What does LSZH mean and why does it matter?

LSZH stands for Low Smoke Zero Halogen. During a fire, this sheath produces far less smoke and no halogen gases compared to standard PVC, reducing toxic fumes. This makes it mandatory in many public buildings, hospitals, schools and commercial installations under UK fire safety regulations.

What's the maximum recommended cable run length?

At 2.5mm² CSA and 14A rating, runs up to 50m are typical for 8Ω speaker loads without significant signal loss. For longer distances or lower-impedance loads, consider increasing the cable gauge or using multiple parallel runs to reduce resistance.

What is the difference between OFC and CCA conductors?

Oxygen-free copper (OFC) has higher conductivity and lower resistance than copper-clad aluminium (CCA). This cable uses a hybrid construction combining both: the OFC strands carry the majority of the signal, while the CCA strands reduce weight and cost. For speaker cable runs under 50m, the performance difference is negligible.

Can this cable be used outdoors?

The LSZH sheath is suitable for temporary outdoor use in dry conditions or inside conduit, but it is not UV-stabilised or rated for permanent outdoor exposure. For permanent outdoor speaker installations, use a UV-rated or armoured cable designed for external conditions.