Your woofer is playing the warps and surface irregularities. All that is certainly less than 10 Hz. That arm does not look all that heavy and I would think the AT would do fine in it. If you want to know for sure you have to get a Hi Fi News test record which has both vertical and lateral resonance bands and you will be able to determine exactly where your resonance frequencies are. If they are below 8 Hz you have a miss match and Ralph is correct. It could still be rumble from the lathe in which case your resonance frequency will be above 8 Hz and it would be the only possible explanation. But if it were rumble I would think you would also hear something as there are components in rumble above 18 Hz as the rumble I am talking about in certain records is more than audible and I also never turn my filter off. There is certainly a fault in those records as you say many do not do this. If you do not have a miss match the only solutions would be get a subsonic filter or don't play those records.
I use a digital brick wall filter at 18 Hz as I have an 8000 watt subwoofer system and at the volumes I frequently listen at I would probably launch woofer cones across the room. Actually what happens is the voice coils hit their end stop and make a very disconcerting bang. Without the filter you can't hear anything down there the house just shakes and you waste a ton of power until the voice coils bottom out. IMHO anyone who listens to vinyl and has a subwoofer system needs a subsonic filter. Even if they have a properly set up tonearm. Unfortunately in the analog world this is impossible to do effectively without attenuating the bass or causing sonic degradation. But in the digital world it is no problem. What ever degradation is caused by digitizing your phone amp is more than made up for by digital bass management and room control.
I use a digital brick wall filter at 18 Hz as I have an 8000 watt subwoofer system and at the volumes I frequently listen at I would probably launch woofer cones across the room. Actually what happens is the voice coils hit their end stop and make a very disconcerting bang. Without the filter you can't hear anything down there the house just shakes and you waste a ton of power until the voice coils bottom out. IMHO anyone who listens to vinyl and has a subwoofer system needs a subsonic filter. Even if they have a properly set up tonearm. Unfortunately in the analog world this is impossible to do effectively without attenuating the bass or causing sonic degradation. But in the digital world it is no problem. What ever degradation is caused by digitizing your phone amp is more than made up for by digital bass management and room control.
