I do believe you’ll notice a difference, although unless you have both to compare you won’t know what your missing. I had an sb2k in my system and although it was mixed in with 2 big ported subs, it just didn’t add much of anything. When tried by itself, and in a smaller room the SB sounded great, but it’s just not an output monster. It might be worth an email to SVS for more technical differences between the pb12 and pb2k but from what I recall, the updated driver alone is worth the upgrade. Iirc, it has more driver protection too. It will only be too much bass if you run them too hot. SVS subs are linear, not boomy so I don’t see that as an issue. Plus they have in home trial.