Actually, I don't need the sub-sonic filter with my Turntable as I modified 4 of the SVS Iso-feet for the subs to mount in place of the useless conical point feet that come with the TT. The medium durometer rubber feet with the 75 pound turntable totally isolates the feedback, I have virtually none. But keep in mind that I machined out the center hole in the steel cup of the Iso-feet to accept a shouldered rubber grommet in which I inserted a stainless machine screw which compresses on the grommet and I also cut 1/4 inch neoprene circles to sandwich between the steel cups and TT base. There is no direct contact of metal to the TT base, it's all isolated with rubber.