Why do my bass drivers shake violently listening to vinyl

It is always 10" or below and always with turntables. With many amps going clear down to DC surface irregularities in the vinyl will cause the woofers to flap.

@mijostyn Back in the old days I used to run some Fried G2s which had a 10" IIRC and had no woofer issues. But you are correct- smaller drivers will flop about without much provocation.

Dear @lewm  : You are rigth in all your last post.

R.

@atmasphere , I was not so fortunate. The 10" drivers in my AR 2ax's use to flop around plenty.

You can make or buy isolation platforms for speakers, too 

Glad the OP solved the problem.  I ditched my analog outfit years ago but before I did I had a hum that resisted multiple approaches to eliminate until I bought a "hum buster" or some such thing that apparently isolated the hum and turned it into light.

  As a confirmed digital lover I have to say there was a. real entertainment value to reading some of the posts in this thread.  I particularly liked the suggestion about putting silly putty on an expensive tonearm/cart configuration