Sub bass that translates everywhere

If your sub only works on a big rig, you have overcooked the sub-40 Hz and left nothing for smaller speakers to reproduce.

Add harmonics, not level

High-pass around 30 Hz to clear the inaudible rumble, then add gentle saturation so the sub throws upper harmonics. Small speakers can't reproduce 40 Hz, but they can reproduce the harmonics — and your brain fills in the rest.

Trust the meter, not your headphones

Headphones under-represent sub. Keep a spectrum analyser and a reference track open, gain-match, and check on as many systems as you can.