Easiest way to add a sub with B&O

[JoeLexus]

https://technicpnp.com/product/logic...harness-wlocx/

Is this all I would need to add a sub to my current B&O sound system. It sounds great and I love the center speaker raises up but it could use some low end bass 35hz~ What have you guys done or reccomend for the easiest PnP?

[JoeLexus]

Also can I use that to add a sub and an amp along with a seperate amp to power my underseat subs? Technic