That's just it, I really don't wanna permanently modify it.....there's a "new and used" guitar joint I frequent when I can afford it and I like to use the amp I have as a trade in like I have in the past. Right now as is, my amp "fetches" $300 at the place I like to go and "window shop". What about a single 12" speaker as long as it has a chorus on it for a more "spacious" sound? Any "better" or "worse" than my 212 open back?