Yeah, this is my problem also and why I'm so curious what differences Mike's hearing that makes him prefer the 846A's simple reflex with its somewhat more 'muddy' bass line over the somewhat more tightly controlled 846B's. Now if both were tuned much lower, then the differences get lost in the room's high noise 'floor' and our increasing hearing acuity loss with decreasing frequency. Indeed, here the reflex can be superior due to its minimal port depth, i.e. no pipe harmonics.

GM