Size

• Speaker wire size perhaps is the most important specification to consider. Quality speaker wire for almost every home audio application comes in 16, 14 and 12 gauge. Generally, longer wire runs require a heavier gauge thickness.
  
  

Material

• Stranded copper wire is the industry standard for speaker wire, and provides effective and efficient voltage transfer. Solid-core copper wire may be used, although not sold specifically as speaker wire, but it often is difficult to connect to components, and run along walls and room moldings because of its stiffness.
  
  

Insulation

• Speaker wire is insulated with rubber, neoprene, PVC and other flexible materials, primarily for internal wire protection, and to keep the positive and negative wires separated. The type and thickness of insulation has nothing to do with sound quality.
  
  

Shielding

• Speaker wires are not subject to radio frequency (RF) interference because of the higher voltage they carry when compared to other wires in an audio system. For this reason, speaker wires are not shielded.
  
  

Connectors

• Speaker wires are equipped with several different connectors. Make note of the connection types on your amplifier and speaker before purchase. Common connectors include banana and RCA plugs, but bare wire binding posts on components and speakers are still popular with some manufacturers.