The next part we need to know about that affects the pressure zone is room loading.
Room loading happens when the sound waves meet at intersections such as the corners and midseams and the mid wall ceiling or floor.
Here's a 2D look at the loading and laminar flow together. Keep in mind the floor and ceiling are doing the same thing as the walls.
All rooms because they are enclosed build sound pressure. Here's a look if the speakers and chair were gone.
Your probably starting to get the picture of how powerful the room is and how big of a role it must play in the stereo's sound. It is without a doubt the biggest component.
A misconception is that the speakers play independent of the room, but lets think about this. How can a speaker play without the room? Air pressure is a function of the room not the speaker. The speaker is a vibrating source that sends the music signal into the air in the room but it's the room that amplifies this signal. A loudspeaker can not play louder or over power what the room is doing. You may think your listening directly to a loudspeaker but if this were the case the music would sound like it was coming directly from the speaker and there would be no stereo image to speak of. The sound would be very sterile as if someone cut away the music.
Take a look at the misguided view of the speaker minus the room if it were possible. Notice how much of the sound waves are cut out.
The only way to remove the room would be to hook a tube from the speaker to your ear cutting out the room altogether. Nope, far better to use the room, and why not? The room can be a wonderful tool that allows you to recover much of the content rather than trying to cut the acoustic information out.
This is why I named the product RoomTune and started the phrase "Roomtuning". We don't want to get rid of the biggest component but use it as the most important and final part of the audio chain. Once you accept this as the "music producer" you can view the hobby with more accuracy.
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