I don’t know what to say about the large towers, I believe they’re the Model T-10. The ones that have 4 8in woofers? These? They’re supposed to go down to 25Hz. I know Bryston has an anechoic chamber and they measure their speakers. Don’t know what to tell you.
I do know that in my bedroom, about 2700 cubic feet, it does a nice job for 2 channel music. Nice and punchy bass. It’s not going to make your bones rattle like my RBHs or other big speakers but for what are technically bookshelf’s (43lbs each), I’m happy and the wife likes them. Actually if it was up to her, she‘d have another pair of 8300s for the room.