Woofer pumping WHY??

The tonearm mass is a low 8.5 grams ,the cartridge has a compliance of 15 (on the low side). That combination looks like a mismatch to me. You can try a headshell weight to add some mass to the arm and see if that improves the problem.

Get a KAB rumble filter for 189 and problem is solved. I had the same problem with my Scout turntable, I tried relocating the turntable to various locations and using all kinds of platforms under the turntable and nothing helped. Put the rumble filter on the tape loop and use it when playing records. All the oscillating speaker problems will go away. I hear no difference with the rumble filter in and out of the system. The only thing that changes is the woofer pumping: none with it on and all with it off.

I had a big woofer pumping issue

In my case we finally isolated it

The bearing in the tonearm wasn't moving properly so there was cyclic woofer movement as the cantilever took the brunt of the motion

We did a feather test suggested by Thom Mackris and that was it

A tonearm tune up and no more issues

One of my threads on it

http://forum.audiogon.com/cgi-bin/fr.pl?eanlg&1400370649&read&keyw&zzwoofer=pumping

What is your flooring type, turntable rack / isolation?
Is it more apparent on the outside grooves of the record?
Is it cyclic or keyed to loud passages or bass heavy parts of the music?

Search engine is your friend

I found 8 threads putting in the words woofer pumping

I have a B3, essentially the sames box, but you have the 12" woofer.
When I see my B3 looking like the woofer is going to jump out of the cabinet, usually means 1-system is cranked and the particular recording is "hot" on the low end, so gain needs to be turned down. I don't keep my sub at one supposedly "perfect" level. While it can be left alone for casual listening and not cranked, ALL recordings are different, so I adjust accordingly. I think REL got it right with the remote for the Gibraltor series.
The second is the actual record.iIf it isn't perfectly flat, when cranked, the movement of the arm over the warp is going thru the cart.
After countless sessions over the years, my REL permanently resides behind the listening position, about equidistant to the floorstnders.
All setups , rooms are different so my experience may not even apply in your setup.
Incidentally, my REL is on Mapleshade brass/slab which I've found not only a nice looking, but sonic tweak. Consider it, if you haven't already.
My floor stander have the same setup.

Ok I'm connecting the sub with the Spkon cable and all three leads to the back of the amp, Otherwise wont the amp then SEE the REL in the system? Before I got the new table I had been using the REL for quite a while with no problems ever. The REL is plugged in to the wall using a 3 prong cable (both the spkon and power cord are from Signal Cable). I do see the woofer pumping on the main speakers too, and this seems to occur more toward the outside of records im playing. The Sound is very very good. If that says anything. But this cone movement needs to be addressed. I'll do a little more troubleshooting and get back soon. Do a lot of vinyl spinners use outer rings?? I see that most of the HIGHLY re guarded phono preamps Don't have subsonic filters? Like my MS Phonomena. I don't think my phono stage is the problem. I respect every ones input thank you. Stereo5 you sound like my older brother..LOL that's what he keeps telling me. He has a KAB. Yogi, Wouldn't the sound be bad or unpleasant with a bad arm/cart combo? because the sound seems to be gorgeous! Al, Im using unbalanced cables to amplifier and my speaker cables are spades, the REL Spkon cable is Bannanas on amp side. I have a concrete floor with carpet. Salamander rack with Mega spikes. Yogiboy, I think is on to something, but the sound is so dam good? So I am perplexed.