i had w7's, to me they are one of the best all around subs. the have good SQ and SPL. sure there are subs that sound better, but dont hit as hard. and there are subs that hit harder but dont sound as good. i think the W7 is a good mix of both. the adire brahmas have great SQ, very nice for the price. i havent heard the BA SPG555 yet but ive been told good things about it.