Chosen Solution

Left speaker began to rumble in the bass frequencies, now the right speaker is beginning to do the same. Had the output volume set to highest. Did I blow them out? Can I replace them?

rkolton you need to identify your MBP properly first. Start here MacBook Pro Repair and select the size and move forward in your selection. according your your MacBook Pro model. For example, if you have MacBook Pro 15" Retina Display Late 2013 you will end up here MacBook Pro 15" Retina Display Late 2013 Repair here. Now you can select the guide to the speakers. I am sure there are exceptions or that somebody says this will not work, but at least it’s a start :-)