4 4ohm speakers to a 2 channel amp - ecoustics.com
Series Parallel Speaker Impedance
I have a jl audio 600/1v2 mono amp that I want to power 2 rockford fosgate 4 ohm DVC subwoofers (P3D410). Is there a way to wire these subwoofers at 2 ohms? - Quora
Subwoofer wiring diagrams
Single Voice Coil Subwoofer Wiring Guides - Skar Audio Knowledge Base & Help Desk