Hmm I think a lot of what you are hearing is a lack of overhang; overhang can give a feeling of big bass and slam, but over time, you realise this is just a characteristic of most "normal" speakers as the drive units struggle to remain controlled.
You might struggle to integrate a sub for this reason.
Mana Acoustics Racks / Bright Star IsoNodes Decoupling >> Allo DigiOne Player >> Pedja Rogic's Audial Model S DAC + Pioneer PL-71 turntable / Vista Audio phono-1 mk II / Denon PCL-5 headshell / Reson Reca >> LFD DLS >> LFD PA2M (SE) >> Royd RR3s.