What is meant by subwoofer room pressurization?

I think of it mostly as an HT phenomenon associated with explosions, etc. where you actually feel a pressure wave. A related but different phenomenon occurs with low pedal notes of a pipe organ, where you may feel more than hear them, just as at an organ recital.

I use a pair of Velodyne HGS-15s with an SMS-1. I set the levesl so the subs are not observable sources of sound.

db

What's the point of subs if they are set so they are not observable sources of sound? I set my subs so they blend seamlessly with my main speakers.

Hew,

Not observable and seamless mean the same thing to me. I aim for a soundstage in which the listener is unaware of any speaker, just fine imaging within the soundstage.

db

Some say that when a wave is unable to unfold that it 'feeds back' on itself. Thus pressurising the rooms' volumn. I think the frequency is about 150 hz for a big room to 350 hz for a small room.

OK, I don't care about movies; I thought it might be an important concept for stereo listening.

Thanks all.