Black Lab: RCA subwoofer cable in solid Long-Grain Copper
AudioQuest Black Lab is an RCA signal cable designed to link the subwoofer output of a receiver or amplifier to the line input of an active subwoofer. It is a single cable, also available in considerable lengths to reach a subwoofer placed far from the electronics.
Its construction borrows the solutions used in the brand's interconnects: solid conductors, foamed insulation and shielding that dissipates noise rather than dumping all of it onto the equipment ground.
Conductors and geometry
The conductors are single-wire Long-Grain Copper (LGC). Compared with ordinary OFHC copper, LGC contains fewer oxides and fewer impurities and has a lower number of grain boundaries; a solid wire also removes interaction between strands, one of the main causes of distortion. The geometry is symmetrical coaxial: the positive conductor and the negative conductor are identical, so the shield does not have to serve as an audio conductor.
Insulation and noise reduction
The insulation is nitrogen-foamed polyethylene (Foamed-PE): the material is low-loss and the high gas content limits the energy that insulation takes up and gives back late as distortion. The metal-layer Noise-Dissipation system protects the actual shield, soaking up and reflecting most radio-frequency interference before it gets to the layer tied to ground. A built-in chassis ground connector helps remove the hum caused by ground loops.
Terminations and lengths
The RCA plugs are gold-plated and joined to the cable by high-pressure cold welding, with no solder. The ground shells are stamped rather than machined, which lets the metal be chosen for low distortion and not for ease of machining. Lengths: 2 m, 3 m, 5 m, 8 m, 12 m, 16 m and 20 m.
Key features
- Use: RCA link between electronics and active subwoofer
- Conductors: solid Long-Grain Copper (LGC)
- Geometry: symmetrical coaxial
- Insulation: nitrogen-foamed polyethylene
- Connectors: gold-plated RCA, cold-welded
