Does anyone use a RUMBLE filter?

If you go to KABUSA.com and look up Rumble filter...They talk about how this is something that is recorded into ALL vinyl from the cutter head. Its subsonic rumble and it makes your amp and speakers do things that are not kool. My brother runs a VPI classsic with a Lyra Delos and he bought this device. He says it works wonders! I posted this thread because I have never heard anyone talk about this problem.

I had woofer pumping with my Pro-ject Xpression III. I tried both a Pro-ject phono tube box and a Jasmine LP2 mkII for phono preamps. I got woofer pumping with both preamps (the Pro-ject phono tube box had a subsonic filter, tried it in both postions, the Jasmine does not have a subsonic filter). I uses an Ortofon MC-3 turbo on the Xpression III. Once I upgraded the table to a Rega RP6 with same cartridge, same wall shelf and same Jasmine LP2 mkII, the woofer pumping was gone. I sold the Pro-ject gear and did not look back. Since you are using a Rega P3 with GT upgrades (I assume subplatter and acrylic platter), I'm not sure where to turn on this. I am using the factory RP6 subplatter and glass platter, but I just ordered a GT RP6 reference subplatter. Do you have a Rega dealer local? Can you ask to borrow a RP3 (either the whole deck or maybe the glass platter) to see if it reproduces the woofer pumping? Does anyone know if acrylic platters are prone to reproduce more woofer pumping (I thought they reduced vibrations) as the Xpression III and Matt's P3 both have acrylic platters?