Woofers getting workout, but no bass

Definitely, you are reproducing the record warps. You need a subsonic filter. Your amps are using a lot of power to reproduce frequencies that you cannot hear, and that you don't WANT to hear. Also, if you are using a heavy arm with a high-compliance cartridge, this makes the problem even worse.

Tell us what cartridge and arm you are using together.

Oh, I just found your answer. The Triplanar/Dynavector XV-1s is a fine combination. So you simply have warped records and a system that reproduces 3 to 10 HZ very accurately. You need to insert a subsonic filer.

Sounds that you can hear, you cannot see. If you see your woofers moving, it means you are reproducing frequencies that should be filtered out.

Could be feedback. If you put the needle down on a record that is not turning do you still get woofer movement? May have to move your turntable. I had the same problem and that fixed it.

Very likely it is simply a matter of ported speakers and the sound is lower frequency than the port tuning frequency on the speakers.

When you have sounds below the tuned port frequecny of your speakers then the woofers flap around uncontrollably and make almost no sound, which is exactly what you have. Sadly, this flapping around will add plenty of IMD distortion to any music you play becuase the speaker drivers are operating way way outside their linear range when they pop out of the speaker in the way you have observed - look for a big port on your speaker probably tuned around 30 Hz to maximize bass extension...

Either you can filter out all the LF electronically or select a different design of speaker...

Yes, ported speakers are more commonly susceptible to this kind of thing from what I have observed over the years, but I think the problem can affect other designs using dynamic drivers as well.

I think since porting is a very common approach to extend low end response on speakers that the problem is more common there, but not a result of the porting itself.

Not sure about IMD distortion, but it still might result in faster amp clipping even with a planar or electrostatic speaker with similar frequency response I would think.