It's one of those things that you'll understand once you experience it. It's a sense that the whole room has become an enclosure for your bass drivers, and you're sitting inside the woofer's cabinet.
10 responses Add your response
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.
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.
I purchased two 15" subs. I first placed both them on either side of my equipment cabinet facing the audience. I was very disappointed in the impact, so I started reading the sub manual and tried different placement layouts. To get the pressurization effect you're talking about I placed one in the front facing the audience and the other at the back on the opposite side of the room. Now I have bass air pressure coming together right at the point of the seating.
It's a sonic boom... like night and day. The room has become a music chamber and the sound of explosions is unreal. The entire house shakes... the sound is better than a movie theatre.