Subwoofer rumble issue

for better of for worse I use EQ on my power amp (crown xti) to make a high pass filter that slopes steep below 30Hz, this removes any subsonics from record warps. If I place the needle down on the record you see the cone bounce without the filter, you see almost no movement with the filter engaged, I find it very reassuring especially as it should prevent any feedback. It may be a band aid to an underlying issue but It does work.

years ago I lost a bass unit on a rega jura. The combination of TT, room, track and record warps led to a loop that saw the drivers very quickly oscillate more and more until the paper cone literally tore open around the center area, this took less time than I could get over and turn the volume down....the other driver survived the experience, I don’t think the voice coil burnt out but somehow the extreme excursion caused the cone to rip.

what I notice on this topic is that when listening to recordings posted on youtube if the track is from vinyl you can often tell as there is obvious woofer pumping, I assumed wrongly that a signel might have been high passed to get rid of some very low frequency hash, apparently not. Many dance/electronic 12 inches not available on digital format have been uploaded and show this.