I bought this subwoofer to replace an older Onkyo that finally died after seven or so years. I will briefly go over the positives and negatives of this item.
Positives: Provides excellent bass power for the price, and can really rattle the room if you have a good system to go with it. It is also fairly small, so it should be easy to find a place for it.
Negatives: The woofer has settings for both frequency and subwoofer volume, but there is no way you would ever be able to run it at max power, so I would have preferred a simpler "one size fits all" sort of approach with just the volume setting like my old subwoofer was. It is EXTREMELY difficult to get the settings just right for the room you have, and it will never be perfect for everything you watch. This woofer can't quite handle the same amount of power as my old one did, and even though I have the settings as good as they can be, it will still clip and distort on certain really loud things, and you can often find yourself constantly trying to adjust the volume on your system in hopes of finding the right balance. My settings are about 3/4 of max for the frequency setting, and about half of that for the volume. Any higher than that and you'll get a lot of clipping or things rattling that never did before.
Overall, this is a good product for the price, but there are definitely better woofers out there. It is also one of the few downfiring subwoofers still available anymore. I am guessing that front firing woofers can give you cleaner sound, but they are more expensive and it can be more difficult to find a good place to put them in your room. Anyways, yep. Nice product that will satisfy you if you want something solid, and I would probably be willing to snag another as a backup for whenever this one eventually dies.