Monoprice

Monoprice 113731 18AWG 2 Conductor CMP Plenum Speaker Wire

4.7 (965 reviews)

CMP plenum-rated 18AWG speaker wire with pure bare copper conductors for safe, high-quality in-wall audio runs.

$73.12*
In Stock on Amazon.com
View on Amazon

*Price sourced from Amazon.com. Last updated:Jun 27, 2026.Price and availability are subject to change.

Affiliate Disclosure: Studio Supplies may earn a commission from qualifying purchases made through links on this page, at no additional cost to you. This helps support our editorial team.

Notice a mistake? Let Us Know

Overview

The Monoprice 113731 Nimbus Series plenum speaker wire is engineered for permanent in-wall and in-ceiling audio installations where fire code compliance is mandatory. Its CMP plenum rating certifies that the jacket material produces minimal smoke and flame when exposed to heat, meeting the strict UL safety standards required for installation in air-handling spaces found in both residential and commercial buildings. Inside the jacket, two 18AWG conductors made from 100 percent pure bare copper ensure clean signal transmission with low resistance, delivering consistent audio quality across the length of each run.

What sets this cable apart from many plenum-rated alternatives is its jacket flexibility. Traditional CMP cables are often rigid and difficult to work with in tight spaces, but Monoprice has formulated a softer compound that bends more easily around corners, through conduit, and along joists without kinking. The red and black color coding on the conductors eliminates polarity guesswork during termination. Sold in a 250-foot spool, this wire provides enough length for multi-room installations or several shorter runs, making it a practical and cost-effective option for audio installers and home theater integrators alike.

Key Features

The Plenum (CMP) rating indicates that the cable complies with fire safety and insurance requirements, making it safe for use inside the walls of residential and enterprise class buildings.

This speaker Wire | features conductors made of high purity oxygen-free bare copper.

Monoprice Plenum Speaker Wire | uses a high quality material that is soft -er and more flexible than on traditional plenum rated jackets.

Easily identifiable Red and Black conductors.

Specifications

Brand
Monoprice
Model
113731
Series
Nimbus Series
Wire Gauge
18 AWG
Conductors
2
Conductor Material
100% Pure Bare Copper
Rating
CMP / UL Plenum Rated
Length
250 Feet
Conductor Coding
Color Coded (Red and Black)
Jacket Color
Black

Pros & Cons

👍 Pros

  • CMP plenum rating meets fire safety and insurance requirements for in-wall and air-handling space installations
  • Pure bare copper conductors deliver reliable signal quality over long runs
  • Softer, more flexible jacket than typical plenum-rated cables makes routing easier
  • Color-coded red and black conductors simplify correct polarity connections
  • 250-foot spool provides enough length for most residential or small commercial projects

👎 Cons

  • 18AWG gauge may limit performance on very long runs to high-power speakers where thicker wire is recommended
  • Only available as a 2-conductor cable so it cannot carry multiple speaker channels in a single run
  • 250-foot length may be more than needed for single-room installations with limited runs
  • No sequential footage markings mentioned which can make measuring during pulls less convenient

Frequently Asked Questions

The CMP rating means this cable has a fire-retardant jacket approved for installation in plenum spaces — the air-handling areas above drop ceilings and below raised floors — where fire safety codes require low-smoke, flame-resistant cabling.
The conductors are made from 100 percent pure bare copper, which provides better conductivity and signal integrity compared to copper-clad aluminum alternatives.
The two conductors are color coded red and black for easy identification during installation.
Yes, Monoprice uses a softer, more flexible jacket material than traditional plenum-rated cables, making it easier to route through tight spaces and around corners.
This spool contains 250 feet of speaker wire.