Why do my bass drivers shake violently listening to vinyl

I have a TT and cart combo that will blow a normal sub 80 hz < but with servo plate amps and servo correction, it’s a tame, deep, very clear bass signal to 25 hz. I’ve always used a spring suspension and gummy puffers for isolation.. A heavy ply plinth, rubber line and spring load the bottom with springs or an inner tube. I use Thoren TD124s and Russco.

The main speakers can’t pump because the bass is cut from 280< and from 100-300hz are bass columns. My system CAN’T pump!! You can throw the TT in the middle of the room... Servo is pretty cool.. ;-)

I use up to 6 12" OB HE drivers. Maybe 100 watts to each driver @ 8 ohms. 100hz < no TT problems..:-)

Regards

Millercarbon, so far you have been totally and completely off base twice in this thread. The OPs problem has nothing to do with the turntable's location. Isolating it will do absolutely nothing. If there is a cartridge mismatch improving that will help otherwise his system is appropriately amplifying the signal that the cartridge is picking up. With smaller woofers this causes excess movement. Next. Stopping that excess movement results in a large improvement in sound quality because of the marked decrease in several forms of distortion. It also results in greater headroom because power is not being wasted. The improvement a subsonic filter will make will be far in excess of any problems it might cause. 
@lewm, subsonic filters are not complicated issues in the digital world, you just program one in. I know this rubs you the wrong way but personally I do not like being stuck in the past. Digital reproduction has advantages that can not be matched in the analog world and the advantages outweigh the disadvantages. I am dead certain you would agree if you could hear it in action. 

I agree with those who say before you do anything, try another turntable in your system at the same location. Whether or not you get the woofer excursion with the second table will determine what to do next. Before you can solve your problem, you have to know what the problem is.

You either need a better turntable with a much better bearing or a very good rumble/subsonic filter on your amplifier.

The OP is experiencing an undamped medium mass arm with a too-compliant cartridge in combination with vented speakers. A stiffer suspension cart, sealed box speakers, a viscous damped arm…any will stop excess sub-bass from causing woofer oscillation. Eric Squires explained how driving a vented speaker below its cutoff frequency is part of the picture, and Yogiboy provided a calculator for arm/ cartridge resonance. Getting reliable data for that from manufacturers specs…good luck! The results speak for themselves. IF OP’s preamp has a processor loop or tape monitor then a high pass filter is the simplest solution but beware unwanted loss of subtle quality cues if the HPF isn’t as good as your excellent Herron phonostage. Maybe they can add an HPF to their circuit??