I had the signature elite 50 a while ago, which were excellent speakers, and now I have the 55s which have even bigger sound and performance at higher volumes. I come from various technics/jbl/magnat speakers that are 30-20-10 years old. The build quality of the polk speakers for our time and in this price range is unique, if you get this speaker once, you will have a hard time being satisfied with anything else in the thousand range. I didn't want to get speakers with paper or copper, I even fear common rubber in the cones, those who have kept speakers for many years know the factors that lead to service and I wouldn't want to see pierced-torn-crooked spots inside in the coming years since I am a lover of high volumes. So, compared to the excellent 50s, I would recommend the 55s for sound of greater dimension, stronger bass at high volumes, bigger cabinet, even lower frequencies, higher sensitivity, and what I like about polk speakers is of course the control and restraint they exhibit in the right places, the speaker produces the sound that I demand to hear, meaning sound with control and analysis. At this point, I will mention that I could have gotten the 60s but I prefer the speakers with 2 woofers because I don't like the cabinet to have too many holes, nor do I want to visually see many speakers around the screen, however, the 60s also enhance the bass and midrange by a notch. If I go up in budget, I will go for the r700s because I can see that they haven't cut corners and have squared touches.