Speaker Cable

Size it to the run and the load: a short run to home speakers works on a small cable such as Mercury's 0.75mm² 807.095UK, while long runs or high-power speakers need a larger conductor such as Mercury's 2.5mm² 801.696UK or Belden's 2.5mm² 70046. A 100V line PA system draws less current, so 1.15mm² cable such as the 801.817UK serves long runs.

It is cable for 100V line PA systems, in which transformers at the speakers let one amplifier feed many speakers over long runs. Mercury's 801.816UK, 801.817UK, 801.818UK and 801.878UK are double insulated for 100V line installations. The CIE Group LSZH-SPKR cables are described for 100v line speaker runs, and the LSZH-SPKR-1.0MM names public address, background music and intercom systems.

OFC cable has pure oxygen-free copper conductors, while CCA uses copper clad aluminium, which conducts less well than copper of the same size. Mercury's 805.850UK and Belden's 70046 are oxygen-free copper, Mercury's economy cables such as the 807.047UK are CCA, and many Mercury heavy duty cables such as the 801.513UK mix copper and CCA strands.

Use it where smoke and toxic fumes in a fire would put people at risk, such as escape routes, public buildings and enclosed spaces. The CIE Group loudspeaker cables, Mercury's purple 807.100UK and 807.101UK, the Securi-Flex SPK-PRO LSZH cables and the SFX SFX/SPK-PRO-4C-LSZH-PNK-100 reel have low smoke zero halogen sheaths. For a stated fire class, the SFX reel lists CPR Fca and the Securi-Flex SFX/SPK-PRO-4C-LSZH-PNK-200 CPR Eca.

When one cable has to feed two speakers or carry a stereo or bi-wired pair on a single run. The SFX SFX/SPK-PRO-4C-LSZH-PNK-100 has four colour-coded cores, red, black, white and green, of 1.31mm² oxygen-free copper in a pink LSZH sheath. Securi-Flex SPK-PRO 4-core versions include the SFX/SPK-PRO-4C-LSZH-PNK-200, with 16 AWG oxygen-free copper cores, and a purple LSZH version.

Yes, with a sheath made for it: the Securi-Flex SFX/SPK-PRO-2C-PE-BLK-200 is a 200m two-core cable with oxygen-free copper strands and a polyethylene outer sheath, described for outdoor use. Where a cable states no outdoor rating, run it in conduit or pick one that does, and seal the joints at the speaker end against water.

By the polarity marking on the sheath or cores: Mercury figure 8 cables such as the 801.513UK carry a polarity line, the transparent 807.048UK and 807.050UK have a red polarity indicator, and red/black power/speaker cable such as the 802.459UK is coloured by core. Keep the marked core on the same terminal at the amplifier and at the speaker so the speakers stay in phase.

Most Mercury cable is on 100m reels, with the 801.816UK on 25m and the 802.764UK on 50m. The CIE Group cables come on 100m drums, and Securi-Flex lengths include 100m drums and the 200m SFX/SPK-PRO-2C-PE-BLK-200. Belden reels include 305m and 500m with some 100m and 152.4m lengths, and the AV:Link 112.500UK is a 10m length.

Usually not: speaker cable carries amplifier output at a far higher level than a microphone or line signal, so conductor size matters more than a screen. Where a run passes sources of interference, a few Belden cables add a foil shield: the 1325A 0101000 has individually foil shielded 22 AWG pairs for security, speaker and control use, and the 4304FLV has a Beldfoil shield and lists noisy environments.

It is Belden cable with two stranded bare copper conductors for security systems and commercial audio, in sizes such as 14, 16 and 18 AWG, and the 4200UE also names intercoms. The 4100UE, 4200UE and 4300UE have LSZH jackets rated CPR Eca, the 5200UE and 5300UE are riser-rated, and the 6200UE and 6300UE are plenum-rated with Flamarrest jackets.