Originally Posted by Operandi
I've heard if you can rub off that kind of print from plastic and metal with a sugar cube. Apparently the sugar is just hard enough to remove the print (probably baked on) but not hard enough to scratch the surface. I've never tried so you may want to give it a shot on the bottom of the speaker where it won't be noticeable just in case.
The bottom of the speaker is covered with a stick on foam pad.