My vintage m&k v125 died about 2 months ago. I finally decided I needed a sub and went to best buy (i know). Bought the def. tech. pro sub 800 and OMG. I think my old M&K might have been deficient for a while. I am running lsi9's thru the subs high pass filter @80 hz and have the low pass crossed at 80hz as well. I am very happy in my small room. I have re-discovered how good of a bass guitar player Paul Mccartney is (band on the run). Wow i'm very happy. So if you are looking for a 400$ sub that you can demo at a big box store do not count out the def tech.