I've been using the Bose Model II for some time and love the vocal sound produced, as well as the guitar sound (solo act). But when I added two small keyboard amps to the mix, wow, what a much bigger, fuller sound. I'm using premixed stereo rhythm tracks from a laptop, which has two audio outputs. One goes to the Bose, the other to the two amps. Even at low volume (cocktail, dinner music), the room is full of sound. It's hard to go back to the Bose alone after hearing the "almost" stereo surround effect.