I've had SongTower RT's as well as Song 3 Encores and now, Song 3 BeAT's. Not sure if you're looking specifically at the Song 3 specifically or are exploring all the iterations. I can give my experience with the models I've had. The ST RT's were in my HT system, and when I sold my Encores I moved them to my 2 channel system while awaiting the BeAT's. When I moved them in, the first thing I noticed was the difference in bass and midrange articulation. After a while though, I began to realize what a great speaker the ST is. While their sound was not as room filling as the Encores, I didn't lack for anything in the treble region. Once I replaced them with the BeAT's (left the ST's with Jim to sell for me) I regained the midrange definition though not the bottom end (which I'd expected). The BeAT's have more bass than the ST's, and just have a fuller sound than the ST's. I would agree with Jim there's more bass extension and impact with the 3 Series. If there was only one of Jim's speakers I could have and cost/space was a consideration it would be the SongTowers.