I just got my Behringer Feedback Destroyer Pro in yesterday, and let me tell you it makes a HUGE difference. For those who do not know, it is a parametric equilizer with up to 48dB of cut and 16dB of boost from 20hz to 50khz. It is all digital based, and uses 20 bit DA and AD 48khz convertors. It was designed for prosound use as a microphone feedback eliminator. But it works amazingly as a subwoofer equilizer. It has 12 bands of equilization per channel as two channels. Have stereo subwoofers? With tha Destroyer, it isnt a problem, they can be equilized independently. With enough equilization you can make your subwoofer flat from 20hz to 100hz +-1 dB, ideally. Why is this good for an "audiophile"? Because, no room is completely flat, like an anechoic chamber, and reflections and echos are going to affect even the best subwoofer's frequency response. For those who are not convinced, go out and buy a rat shack SPL meter and run sine waves from 20hz to 80hz, and measure the output at each, you will probalby be surprised. So in closing, I dont see any reason for not buying one unless you have monetary concerns of course, they only cost 130 dollars brand new. I got mine for 85 used on ebay!