Monoprice 113735 Nimbus 18AWG 4-Cond Plenum Speaker Wire 500ft

The Monoprice Nimbus Series 113735 is an 18AWG, 4-conductor speaker wire packaged on a 500-foot spool and built specifically for installations that must meet plenum fire safety requirements. Its CMP rating from Underwriters Laboratories certifies that the cable jacket resists flame spread and produces limited smoke, making it compliant for use in the air-handling spaces above drop ceilings and inside HVAC ducts found in commercial buildings, schools, and offices. The four individually color-coded conductors allow a single cable run to carry both left and right audio channels to a stereo speaker pair, cutting installation time and reducing cable clutter in conduit or open ceiling spaces.

Each conductor is made from 100% pure bare oxygen-free copper, which offers lower electrical resistance and more faithful audio signal reproduction than the copper-clad aluminum found in many competing products at this price point. The 18AWG gauge is well-suited for typical distributed audio systems with moderate run lengths and standard 8-ohm speakers. For longer runs or higher-powered systems, Monoprice offers the same Nimbus plenum wire in 12, 14, and 16 AWG options. The entire cable line is covered by Monoprice's lifetime warranty, providing long-term peace of mind for permanent installations where replacing wire after the fact would be costly and disruptive.