Let me throw into the mix a very critical factor. Sub placement, sub calibration...and a huge one is sub equilization. High end subs, such as SVS (which I have) are designed to give a flat response (meaning no peaks in the Hertz spectrum). That's all fine and good, but when room acoustics and sub placement are at maximum, you may still run into an unbalanced sub frequency. I, for example, purchase the Rives Audio CD 2, which I'd recommend to anyone who uses the Radio Shack SPL meter and did a reading. Low and behold I had a spike of 6 decibals in the 50-60 Hz range! That's huge when playing at loud volumes. That will make any sub sound boomy.
So keep that in mind when shopping.
