Here is a portion of an email I received review on the S1 pro...

"I have owned Bose products and used them for gigs since the 1980s. I presently own a Bose L1 Mod 2 and an F1 along with two of these S1s.

Bose has hit a massive, tape-measure Home Run with this product. The sound is awesome; Bose clear and crisp WITH bottom end. Produces plenty of sound for small to medium sized rooms. I've run them on battery for at least 4 hours with power to spare.

I was practicing in my studio with a friend last week, 2 electric guitars, 2 voices, drum machine and was surprised when I realized that the F1 I thought was teamed with the S1s was MUTED. LOTS of sound volume and clean and clear response.

One of these is truly wonderful. Two of them are Awesome! The Best sound I know of - and they fit easily into my 2 seat sports car with all the rest of the gear..."