SUBWOOFER VOICE COIL TYPES
Explaination of different voice coils available on Rockford Fosgate subwoofers.

Single Voice Coil
(4Ω / 8Ω)


This is a Single Voice Coil subwoofer with one set of wiring terminals on the backside.  This denotes one winding on the voice coil former having one (+) and (-) input terminal. The nominal impedance of the voice coil can either be 4-Ohms or 8-Ohms.



Dual Voice Coil
(2x2Ω / 2x4Ω)


This is a Dual Voice Coil subwoofer with two sets of wiring terminals on the backside.  This denotes two windings on the voice coil former, each with their own (+) and (-) input terminals. The nominal impedance of each voice coil can either be 2-Ohms or 4-Ohms.



Dual Voice Coil SWIFT
(2x2Ω / 2x4Ω)


This is a Dual Voice Coil subwoofer with one SWIFT (Selectable Woofer Impedance Fused Terminal) connection on the backside.  This denotes two windings on the voice coil former, but having only one (+) and (-) input terminal. The nominal impedance of each voice coil can either be 2-Ohms or 4-Ohms. SWIFT 2-Ohm models are configurable to either a 1-Ohm or 4-Ohm load. SWIFT 4-Ohm models are configurable to either a 2-Ohm or 8-Ohm load.