Don't see if you'll be using this for HT or music primarily, for music there are no instruments I know of, beyond a massive pipe organ, that would play below 40Hz. HT is different, and for that I'll just suggest you read the above post, room placement plays a large part, if I ever had time with the house quiet I would take some measurements on the EMP, it certainly hits lower than it's 35Hz point. In a nutshell I'd say it's a tight sub, great for music and with proper room placement in particular it hits hard enough for HT duty. As always, things are a compromise, only if you want to spend significantly more than $200 will you find a sub that hits low 20Hz and still has great musicality and mid-sub range impact.