Ground work first - I have a moderately priced 5.1 system centered around a new Onkyo tuner/receiver. The sound output is exactly what I needed for a medium sized apartment except, without a powered subwoofer, I didn't have the needed body and fullness to the system. Hookup was quick and simple - but when I turned on the system there was no output whatsoever from the Sony. I fussed around a little bit and then figured I got a non-functioning unit - complete disappointment.After several hours of jiggling the individual volume controls on the Onkyo I figured it all out - and now I am totally pleased with the performance - fullness, great body and roundness, no annoying rumble - the sound is very satisfying and complete.Here is what I had to do to complete this 5.1 performance. My Onkyo has separate output adjustments for each speaker - ranging from -12 to +12 - allowing the total sound to be adjusted to fit the room and accoustics. Without the sub-woofer I had each speaker adjustment close to the maximum plus (+) settings, +7 to +10. When the sub-woofer was added, these high plus settings required a low output of the volume control dial which meant little power signal to the sub-woofer.Fooling around with adjustments to the individual speakers for several hours, it occurred to me to lower the power of each separate speaker to the range of -10 to -7. This worked perfectly because it required a much higher setting from the volume control dial to all of the speakers, including the sub-woofer. I hope you are all following me here. Anyway, the sound from the system is now in balance with the addition of the Sony sub-woofer.Crossover fits perfectly at the 150 range. Also, the automatic shutoff works great - the sub-woofer always stays on, without interruption, when the Onkyo is sending sound signals to the speakers, and the Sony automatically shuts down when the receiver is turned off.So, if you take the time to set the system up properly, the Sony sub-woofer is the perfect inexpensive addition to a moderately priced system. By the way, the construction is NOT a work of art - but it doesn't lower the rating in my mind.Don't hesitate to make this purchase.