Sub frequency issues with vinyl

[Confused]

I read "Devialets" to mean Phantoms...hence most likely the OP is describing acoustic feedback?

Ah yes, it looks like you are right.  I should have read the question more carefully, my brain is wired for Expert.

So this then begs the question, what is the OP using as the phono stage, and does this have any kind of low frequency (sub 20Hz) filter option?

As an aside, the Phantoms inherent latency should actually be advantageous in terms of avoiding acoustic feedback, but this is only part of the problem, turntables are incredibly sensitive.  Without a low frequency filter, I can walk towards my turntable and see the woofers responding, and this is with a solid concrete floor.