Best way to connect Dual Voice Coil Subwoofer

5.

I would test the various configurations that work numerically speaking.

However, in the end, I expect that driving each voice coil with it's own amp channel will be more useful than other alternatives. The reason for this would be the fact that despite being the same nominal impedance, manufacturing tolerances will make it so the two coils won't be the exact same impedance. This will make the different coils behave differently, even though they are electrically coupled. Where as if they are mechanically coupled, using the same diaphram, it will mean that you cannot hear asymmetric output issues that can arrise with impedance mismatches in two driver acoustically coupled systems.

The only real issue you avoid wiring the coils in series and the drivers in parallel is back EMF. Which is reason enough. Any variance between thew two coils in the woofer average either way and if the differences between two woofers in the same box is so significant as you cause a problem, then they aren't the same woofers

You have put it so straight forward!
I don't know why I had been staggering to get there
Thank you!

Need to be careful. I understand a special amp is needed, not a full range stereo or mono amp, you could blow voice coil. call the manufacturer or call a shop for advice. good luck..

How will you power the amp in a home? Car audio needs 12V power while homes are 120V, at least in the USA