Hey all, Chiefs fan here. I was planning on just lurking, but figured I'd weigh in on this subject since I'm probably one of the few people that attended both the Denver @ Dallas game, and the Denver @ KC game.
Let me start by saying I was impressed with how loud Dallas was. I attended a game a few years back and the place was like a library. This year was different. The crowd was really into it, and the people that run the audio/video do a good job of cranking out the sound and getting the crowd hyped.
In my estimation, it was pretty close between the two games. Of course I'm using nothing other than my untrained ear and my experience of attending a lot of different stadiums.
Texas stadium cranks the audio at a high volume, and pushes the limit on when they are required to cut it off by the NFL. That combined with the fans, and the semi enclosed stadium goes a long way in making things noisy.
Arrowhead, while it may have had an extra 15K people, also is an open stadium. Combine that with the fact that it was about 9 degrees that evening, and everyone was wearing gloves, and the home of the Chiefs was clearly not at it's loudest.
So I'd say it's possible for those particular games, that Texas stadium was louder. I'll also say when Arrowhead really gets rocking, Texas stadium doesn't come close. Unfortunately our defense has a tendency to steal our wind with their poor play of the last few years.
One more thing to note. Cowboys fans like to get loud when their own team is on offense. The jumbotron are asking people to keep it down, but a lot of people aren't getting it. You guys need to remember that when your O is on the field, a quiet stadium makes it easier for your QB to audiblize and your linemen to hear the snap count.
