Buy High Pass Filter or KAB RF1?

@craigert I am having the exact same problem and dilemma about what to buy as you are! Wow...was about to post myself. I ordered some Harrison Labs "FMODs" (20 Hz high pass)..I plan to put one on one channel to start and see if I can hear a difference in sound. I hope they solve my woofer pumping.

My Focal Aria 906's are getting "woofer pumping" when I use my turntable as well.  I've tried EVERYTHING, it's not an isolation problem (verified by moving it all over and trying different experiments...and making a digitial recording from my 'pre-out' into a digital recorder and playing it back, the problem STILL persists!)
@stereo5 any idea what's actually causing the problem? I have the same issue as you can see above in this message :/

Ok thank you so I am in compliance. Plus Rega told me people use this cart with my P3 all the time. 
Will a KAB fix a feedback problem? Just curious. 
I thought rumble could be caused by feedback but I have somebody telling me a filter wont fix feedback.

@craigert I'm sure it will...I had someone come over today with a preamp that has a subsonic filter built in and the issue went away. I can't speak for the KAB, but I may have to buy one someday as well so I hope you let us know how it works out if you do buy one :)

Just build your own and experiment.  $25 filter is just probably a resister and a capacitor.

Thanks Brandon I’ll stay in touch! I just saw your first post. This is crazy isn’t it?

im now thinking about buying the out board pre amp first so I can get the table away from the speakers and see if it’s a feedback issue. 
I have also heard that you can buy a test record that will help to identify the problem but it’s like $50.

i also saw in another similar thread that if you turn on the turntable but don’t play the record and then crank the volume way up that if the speakers pump it’s a feedback problem. 
Finally somebody told me if it’s a feedback problem that a filter won’t work but I thought that “rumble” = “feedback” problem.

i am convinced a simple passive filter will hurt sound since the designer of one mentioned in this thread told me it technically does. He said whether you hear it or not is another story. I have also read that while an active filter may not degrade sound it may throw the bass out of phase. 
I thought I was simply just going to buy a record player and spin records a couple months ago. Lol