I decided to quickly try to draw diagrams showing what I attempted to explain above...
Here's what happens when there are two bass drum beats back to back played through an outdoor or very large room PA system:
The sound reflects off the ground (less so with a huge crowd sitting or standing on the ground absorbing bass), but is not very much delayed from the initial sound. The two waves pass over the user and he feels the pressure waves as they pass by. Then they continue onward forever. In my diagram the waves are shorter than real life, and far too close together for a double bass drum hit. But this shows what the sound does, in essence.
In a room, the same double bass drum hit can be visualized like this:
This is just for two dimensions and you can quadruple the number of reflections for the double hit if you add the left and right side walls, increase the reflections by even more of you add multiple subwoofers in different locations.
In the room example the initial sound passes over the listener along the floor reflections immediately behind it. Then slightly behind that is the front wall reflection, the ceiling reflection, then the rear wall reflection followed by the tangential reflections from the floor bounce and ceiling bounce reflections, followed by the rear wall reflection reflecting back off the front wall, and so on and so on, until the energy is lost to physical movement (the drywall vibrating from the sound) or it is lost to heat (the acoustic energy converted into the micromovements in absorbing materials), or so on.
This is why it is damned near impossible to recreate the power and impact of the bass in a live concert or huge movie theater in a home environment. It isn't necessarily the size of the speakers, number of speakers, or amount of power amplification. It is more about the sense of impact being completely obfuscated by the long decay times and rumblings boomy room modes.
It is kinda like playing pink noise at you constantly compared to the impact and instant decay of a snare drum being hit. It may be the same spectral makeup, but one is extremely dynamic while the other is just a nauseating and droning noise.