Evil? I'm being thoughtful.
And yes, you need at least one, if not two or three more!
Then you can center the bass properly, make it increasingly difficult to localize and more enveloping.
You can get flat frequency response at frequencies where it's difficult.
You can get quicker decay of notes where even now you're getting a little bit of monopole overhang.
You know you waaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaant it.