Why do my bass drivers shake violently listening to vinyl


Hello Gon'ers,

Help needed. I took the grills off my new Vandersteen Treo CT's recently and noticed that when listening to vinyl, the bass drivers shake violently, meaning the amount and frequency in which they travel in and out. Then I played the same pieces of music from Tidal and they were relatively calm.

Is this some kind of feedback loop causing this? Has this happened to anyone else?

Thanks!
Joe
128x128audionoobie
I purchased the KAB rumble filter. As soon as it comes in I will post my findings. Thanks all for the enlightening discussion. 
lewm:
I don't know by what mechanism a phono pre or IC's can cause rumble problems the electronic wizards can give you dozens of explanations sometimes they can even find the reason for the problems other times it is all a mystery to them. All I can tell you is this, we have seen some weird and unexplainable things in the years we have been in audio. Once a manufacturer claimed it was a cracked IC board that caused the rumble problem. We have seen phono preamps and IC's that could pickup CB, airline and police broadcasts, electronic noise from passing vehicles and just recently we had one that was able to pickup noise from a flying drone, so picking up noises that can cause rumble is not out of the question. My job is to find the problems and fix them not explain why they happened. I can tell you from experience there have been times when replacing a phono pre or IC's  solved a rumble problem. You are correct about considering a platter bearing as a source of a rumble problem many times it is, my bad for not mentioning it. I mentioned the Technics tonearm because we have had so many problems and compatibility issues with them in the past.

Microphonics are real. I used to have a phonograph preamp that you could smack and have it ring through the speakers, but the very very first problem you face is the cartridge itself. It’s essentially a microphone with a needle and the LP acting as a diaphragm.

The microphonic pick up of modern electronics however tends to be very small to none, and much higher in frequency.