@mitchellcp I think this problem is super interesting and part of what makes the hobby so fun (I think we're all gluttons for punishment). Thanks for posting this, I've enjoyed learning from the other folks who are posting ideas. I am not sure if it has been asked and I couldn't see in the video, but does the woofer movement happen on both speakers and in phase with one another at the same time (both channels)?
So Weird- No Stylus Contact Woofer Pumping with Hana ML and Elac PPA-2
I observed the weirdest thing I have ever seen in audio. With the cartridge positioned above the record, tone arm locked up and platter spinning, the woofers were pumping on my system. I googled every permutation of query I could think of but came back with no hits. That’s when I decided to video the problem- link below:
I could type out all the details but the video pretty much covers everything. I thought ya’ll might be interested in this.