Originally Posted by PeteJames
What's it all about?
There are more variations beyond those too!
TB2 was the original replacement for the TB1.
TB2+ is an improved version, with better tweeters and crossovers. It is possible to upgrade TB2's to + spec.
TB2i is the hifi version. With fancy polished wood finish, different tweeter, and different crossover specs.
TB2S. S stands for studio, so those are all painted matt black I believe.
If I remember rightly, some also had magnetic shielding(?) so those had an "M" in their name too. I've a feeling they all come with magnetic shielding now though?
Then you have around 3 or more variations of the active models.
I notice the very latest powered versions are reviewed in the current edition of Sound on Sound magazine, if you care to look