Yes, the range is mp-fff. Although the fff is only available on the marcato legato (instead of regular legato) but you can switch to it fairly seamlessly during a crescendo as shown here. I would love to have true, ultra mellow p and pp brass samples but it seems like you need to buy Albion 5 or Metropolis Ark 2 to get em. I would rather be missing the bottom end than the top though. I can tell you from comparing CSB to other libraries like Berlin Brass, Hollywood Brass etc., this is the only one that has true fff. (although the horns in Hollywood Brass are pretty great) It might not sound totally overwhelming at the ending crescendo there, but that's because in a real orchestration it would be buttressed by high winds, string tremolos, and above all the timpani and cymbal.