What is it that you are looking for? Chorus ll has a much better professional quality woofer and the Chorus ll essentially replaced the Cornwall. Have you taken the time to decide what size woofer that you prefer the most? This is important. I happen to like the sound of ten inch woofers myself. So in your mind what is it that constitutes an upgrade? What is it that you are looking to achieve? What is it that you want your next loudspeaker to do that your Forte ll don't? A Forte ll has deeper extension than a Chorus Cornwall or Khorn. please not I said deeper, the other speakers in their band can play louder but not deeper. If you want improved spatial stage and image then go with the much better and newer horn designs like the CF3 or CF4 or even a KLF30. Two 12 inch woofers will push 1.5 times as much air as a single 15 inch woofer can so if moving air is what you want. But you need to decide what it is that you want. Hope this provides some food for thought. Best regards Moray James.