What is meant by subwoofer room pressurization?

Bondmanp is right. If you have a good sub that can dig deep and you're minding your own business watching a movie AND all of a sudden your clothes move before you hear anything, you have experienced room pressurization.

But don't make a buying decision based on that factor. There aren't that many movies that "stimulate" you in that way. Buy one that is clean and defined down to 20hz or so and you'll be happy.

I have an SVS PB Ultra 13 and I don't run it "hot". As much as I like bass material, I don't look for it when it's just not there on the recording.

-Brew

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.