Why are my woofers pumping?

Audiotomb - very interesting. I think my arm floats fine but will check when i get home. The HFN record lateral test shows very visible and sonic resonance ca 7hz while the vertical test is much less obvious (the test tone warbles a bit between ca 10 to 5hz).

"If you have rumble problems, get a light feather!" Who said this hobby was boring?

Update: situation in the system at the cottage seems like with the main system at home. Vinyl records including DSD recordings of these made by the same cart-arm-phono-preamp in the main system, create pumping, more or less. Its not just Meddle, but e g Glass and Shankar too and Sade: Love is... When I play digital from the Oppo player I have here - no pumping so far at least, testing SACD Moody Blues: On the threshold, and CD Spirit: Sardonicus.

There is pumping with vinyl but maybe it disturbs less with the smaller speakers and less linear amp here. I also note that there are more energetic vibration from the vinyl (slightly touching the cones) compared to the sacd and cd. My ears tell me I prefer vinyl - this is why i bother to make recordings. 

It seems that to use the single ended Kab filter from the balanced outputs of my phono stage (having tested that these sound better than the single ended outputs) I will also need a converter box. It becomes complicated.  If KAB was next door of course I would have tried it by now, but it means shipping across the Atlantic and maybe taxes just to have a try. Kevin at KAB has been helpful.

o-holter

if you have addressed the turntable, and your amplifier is not blowing its brains out, then it leaves one thing - acoustic feedback. 
what is under the hard wood floors in your room. Do wood beams run under the floor ?   

I have been thinking: the main culprit is the cart-arm combo's low resonance. But is it? Much is in the blue, since the HFN test record is known to be somewhat problematical (e g dont use it to set antiskating), calculators may be crude and we dont even know the exact cu at 10hz for the Lyra. It is 12 at 100 so MAYBE 18 at 10. Or 20 or 22. These numbers make a difference in the calculators.

The basic idea is that the pumping would stop if I change to a lower compliance cartridge - or to an arm with less effective mass. Then the HFN test would presumably show a resonance at ca 10hz - where we want it.

The Kuzma 4point is three grams more mass than the SME V. It should have even more resonance problems than mine. Yet Michael Fremer declared the 4point/Lyra combo so good he could not get over it. It seems that the Atlas sounds good with more arms than the calculators and test record would suggest.