What wire gauge do I need for speaker cable?
A. This depends on a couple of factors, including the length of the cable runs and the power of the amplifier. For runs under 50 feet, with an amplifier of up to 50 watts, use 16 AWG wire. For runs over 50 feet, or with an amp from 50-100 watts, use 14 AWG wire. For long runs over 100 feet, or amps 100 watts or greater, use 12 AWG wire.
Choosing an appropriate speaker wire requires consideration of two parameters – current delivery and cable length. Small speakers working from bookshelf systems rarely demand more than 1 or 2 amps of current. 16AWG wire is sufficient. For runs over 50′ moving up one wire gauge to minimize voltage loss over the length of the wire may improve the quality of the bass and dynamic impact. Larger, high performance speakers driven by larger amplifiers are capable of delivering 10 amperes or more of current to a speaker. For critical installations a 14AWG or even 12AWG wire is appropriate. Speaker voltages rarely exceed 50 volts, so Class 2 wiring for in-wall applications is sufficient. Class 3 wiring is rated for up to 300-volt applications.
