Why the woofer moves badly when playing certain LPs

Hi Starbusters, many lacquers are now cut on old poorly maintained lathes. They can produce prodigious amounts of rumble coming from both the main bearing and the worm drive of the cutter head. This will cause your woofers to bounce around and even bottom out. With most speakers the rumble is so low down you won't hear it and if you have grill cloth on your speakers you might not even notice it. In my case having four large subwoofers the whole house shakes. I have already sent three records back this year alone due to this problem. It can be made worse by poor tonearm/cartridge matching but I do not think that is your problem. At best this robs you of power and Doppler distorts everything else the woofer carries. At worse it makes you whole house shake. When you get a record like that send it back and complain. Unfortunately, most people do not recognize this problem so do not complain. 

Actually, many of the lathes now being used have been rebuilt (having been recently rescued from years of storage) to better-than-new condition. Your problem may be that modern mastering avoids the use of the bass filtering that used to be common practice: rolling off the very low frequencies contained in a recording so as to make groove tracking by cheap, mass-market cartridges less demanding. Some current phono amps (Herron for one, I believe) include a rumble filter.

@mijostyn  I highly doubt that mastering lathes are to blame- too much is at stake! I have yet to buy a new LP and run into anything like this; OTOH many of the new LPs I've bought seem to have deeper bass than many of the older LPs (I like electronic music...). I did run into one LP which was overcut, causing distortion on bass notes, but overcutting is simply a mastering error on the part of the mastering engineer. 

One fairly simple explanation for the complaint is the cartridge has compliance too high for the mass of the tonearm.