I am currently using the Mac Pro's internal speaker. I am not interested in getting the typical Bluetooth or wired "external" speakers. Instead, I am wondering if there is such a thing as a "pluggable" and "unpowered" external speaker that just plugs to the audio out on the front of the Mac Pro and has two tiny speakers to give stereo sound. I understand sound quality is limited; I simply want stereo sound capability that is a bit louder and clearer than the internal mono speakers. Any suggestion?