I purchased a pair of KSP 400's and found the subs were not working. Removed both speaks and the they were fine. I then bypassed the internal crossover and wired them to my Crown K2, via a Behringer corssover. Their signal is from my main l/r on my Yamaha receiver. Everything wide open and i get a mild thump. With the power of the K2 I am totally baffled. Any ideas? Thanks, Rich