Yeah ill make a quick clip and theres no heavy guage strings just .9s
Without hearing this is just speculation but the first thing which springs to my mind is EQ have you rolled off the bottom end on the recorder/DAW or on the amp? You will be amazed how much more bottom end you get and need to get a propper THUNK THUNK THUNK! you probably wouldn't notice it was missing on normal playing.
when I've recorded stuff like this your get really big peaks at (From memory so it may be wrong) 100hz and lower.