I'm not an audio guy so pardon the ignorance (and possibly dumb question). I need to hook up a speaker to my Arduino. My existing shield (EasyVR - it's great, by the way) already has an amp built-in, as well as a headphone jack. I have my computer speakers hooked up to it right now, but I'm having grounding issues so I need a dedicated speaker. So riddle me this: I have the Arduino with amp and headphone jack. If I were to get just one of those bare speakers (arbitrary product link), how would I go about connecting it to power and/or aux out?