How Do I Wire Up 2 Dual 4 Ohm sub-woofers to get a 1 Ohm Impedance ?

This image below shows two 4 Ohm dual voice coil woofers with the coils wired in parallel. This presents to the amplifier as 2 Ohms. The sub-woofers are then connected in parallel which further reduces the presented load to 1 Ohm.