You pose some good questions, Jonathan. The most basic answer is "yes, if you use regular electrical wire a speaker could work" -- as long as you have two same-size conductors for positive and negative, you'll get sound. There are differences in the metal used and in shielding (for some speaker wire, but not all). There are also some considerations regarding solid vs stranded that I don't remember at the moment but will try to dig up later -- I'm about to unhook all the computers so we can paint the study today.

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Gonk