How to fix woofer pumping


Hello,
Looking for a little assistance/advice. I recently noticed some pretty severe "woofer pumping" while playing at a fairly high level. I don't think it's feedback, as it will not "run away" and get worse, just seems to suck the power out of the base. My system is in a fairly open room, system pics are accurate placement, but the gear has changed a bit. Last changes were getting rid of a ML 32 pre and replacing it with a VTL 7.5 plus the Ayre P-5xe phono pre. The ML had a rumble filter, which I used, the Ayre does not. System:
Clearaudio Champion 2
Clearaudio Titanium
Wall mounted with granite
Any help is appreciated.
128x128putty

Sometimes you don't have the option of moving your turntable - or anything else, for that matter.

I got the KAB rumble filter - and believe me, it works like a charm.

It does not have the slightest effect on playback.
Thanks all for the responses.

Anyone have any information on how to tell if the arm/cart are a good match?