I removed the speaker because it would have a little vibration/rattle only when I played notes lower than open E on my 5 string. I didn't feel like diagnosing anything so I just purchased a replacement. The speaker sounds great when playing just had that occasional annoying rattle.
I am selling this AS-IS since I don't know what is causing the sound. It could be something simple and easily fixed, I just didn't feel like bothering with it.