If I attach a large magnet to the magnet of a speaker driver, what happens?

[Willzville]

I'm making a artsy speaker for a school project. Because of my tilting design, the speaker (a mid-range driver) has to be quite heavy, and I'd like to use room for extra weight to improve the speakers functionality.

If I attach a large magnet to the end of the mid-range driver, what happens to the sound? Would it increase the volume and/or quality?

Thanks for any help!