Instruct: Classify an Amazon review into positive or negative sentiment.
Query: Great bang for the buck

I bought this sub to upgrade from a $100 Sony 10-inch sub as my movies were just missing "something". Wow, was I impressed. I did an $1100 audio upgrade (new Onkyo TX-NR709 AV receiver, Rotel 5-channel amp, and this sub) and I can honestly say that at least 50% of the audio improvement for my $1100 came from adding this sub. Prior to Audessy calibration, this sub would shake the walls, windows, and the couch I was sitting on! I like deep bass but not to have my windows rattled- that is effects that belong on a roller coaster simulator, not for movies (IMHO). Once calibrated, this sub gives the perfect amount of bass. The thanator chase in Avatar has the room shake JUST A BIT when needed, but I hear all the deep bass sounds needed. This is an amazing subwoofer, worth every penny. I probably could have just bought this subwoofer and not done the rest of my audio upgrade!