each coil's 2 ohms, so the amplifier sees 1 ohm
and if you have a DVC (dual voice coil) speaker, you HAVE to wire both coils
So a dual 2 ohm sub can be wired to either 1 ohm in parallel or 4 ohms in series.
It's to give you the most flexibility when wiring multiple sub configurations. There's a lot of amps that are stable down to 1/2 or even 1/10 of an ohm.
and if you have a DVC (dual voice coil) speaker, you HAVE to wire both coils
So a dual 2 ohm sub can be wired to either 1 ohm in parallel or 4 ohms in series.
It's to give you the most flexibility when wiring multiple sub configurations. There's a lot of amps that are stable down to 1/2 or even 1/10 of an ohm.