Some LPs have infrasonic frequencies "cut" into the record grooves as the master disc is made. I experienced it mostly with classic rock records, not as much with jazz records. I understand warps can also cause rumble. The KAB website explains it in more detail.
Any type of filtering is controversial among audiophiles as it messes with the signal and adds another component in the signal path so purists frown upon it. I had a rumble problem with my previous setup and I couldn't bear looking at the woofers jumping out of the speakers sometimes even before the record began to play. I got the KAB and never looked back. From the many rumble threads on A-gon over the last few years feedback from the KAB owners appears to be overwhelmingly positive. My experience has certainly been just that.
