The TSB is meant to fix the cabin booming sound while driving over bumps or rough roads. We're not suppose to have cabin boom at slow speeds which is what the 04' Armada suffered. The 04's roof flexed because they weren't anchored properly to the cross beams between the headliner and the roof. This fault resulted in the roofs ability to flex up and down going over bumps or rough roads. The TSB epoxies the roof to the the cross beams and stops the flexing of the roof over bumps so the booming sound ceases.
This is the problem I had mentioned above and is no longer existent thanks to the TSB.
Now let's talk about when you get the booming sound again at higher speeds usually around 50 mph or above with the windows or a window down. The wind gust coming in and out isn't constant, thus, the air in the car isn't constant which is pushing and pulling on your eardrums giving you that buffeting feeling in your eardrum. The windows aren't large enough to let the air flow more freely at that speed creating a vacuum in the car. Drive in a convertible with the top down and you won't get booming in your eardrums because it's fully open. The wind is everywhere moving freely and not through some tiny window. What the air is trying to do in a closed in car with the windows down is looking for more places to relieve that vacuum so it looks down your ear (drum).
Another analogy is like an airplane. Over 10k ft. the plane has to pressurize to keep the bulkheads from caving in from outside pressure. As you pass the 10k ft. ceiling, that's when your eardrums pop.
In a car going faster and faster with the windows down, the pressure is pushing and pulling air in the car again....or...pushing and pulling on your eardrums.
So with all this said, I hope you understand a little more about the booming issue. YES, I still get booming sound flying down the freeway with any window down and thats normal. If I drive slower than freeway speeds over rough roads or bumps, NO, I don't get that booming sound I used to before the TSB fix.
Read the TSB more closely...it says (Quote) IF YOU CONFIRM: A "booming" noise is heard in the cabin while driving in rough road surfaces, NOTE: This incident may be described as a "buffeting" sound, or an air pressure "pulsation" that is heard and felt in the ears. (Un-quote).
Hope this helps.