As has been said, it is not the deepest or loudest by any means, but the real question is how much do you need?
What have you had in your past?
If you will use it for music, the low end is not a factor unless you are a pipe organ afficinado or listen to some of the deeper synthesized bass. Most traditional instruments drop out at above 30Hz. For HT, you will be missing out on the lower frequencies. On the other hand, if this is your first sub, you will love it for the bass it adds to your system!
How loud is a question best answered by testing it in your room at your volume with your content.
One of the issues I have with that sub is it doesn't offer much in adjustment to allow you to tune it to your room. That is one of the biggest improvements and has now become fairly common.
In my experience with NHT (a Classic 3 speaker) and by reputation, they make well designed and well built products and I'm betting at ~15 years old, it is still works great!
Do the subwoofer crawl (link below) and see how it works for you. Subs can be problematic because your room controls so much about how it sounds. If you are lucky, you can dial it in quite nicely, if not, you may need to try something else.
But it is free and of good quality, so give it a chance!
PS - the time you put into the sub crawl will generally prove valuable should you get another sub later, because the sweet spot for one sub usually carries well to a different sub.
There is a video if you prefer, just scroll down a little ways:
Subwoofer Placement: An easy guide for placement of your home theater subwoofer. Crawl for bass to find the optimal location and achieve the best sound.
www.audioholics.com
