Yup, I have certainly noticed and enjoy the fuller sound of the music the sub provides. I expect with more time I'll feel the same way.
Having owned a sub (actually the complete 5.1 system) for just over a week (and not knowing anyone else that has one), I was really surprised by the subs output when viewing a couple movies I'd watched before I owned the sub (e.g. Darla tapping on the aquarium in Finding Nemo and some scenes in Flight of the Phoenix).
It's all fun and my ears are happier than they ever have been thanks to Axiom and you guys. To think I almost bought a little HTIB for only a few hundred less. Thank goodness I found Axiom and this board first.
