need help figuring out rattle under hood *video included*

[xFuZzYx]

Hey y'all, so I have an issue with a rattle/squeak from under the hood of my tahoe. I think that it may be my belt/tensioner but im not sure, it makes the noise even at idle without the AC on. Also if I go into higher RPM's while driving and my truck shifts at these higher rpm's there is a loud squal like belt slip, I have a 270 amp alternator and it has a smaller wheel so I had to install a shorter belt, any help is appreciated!

https://www.youtube.com/watch?v=IhWF6HwkcuE
you can start to hear the rattle/squeal at 0:29

 

[Sasquatch]

Are you serious with that video? The only thing i could tell from it is that you have a loud stereo.

 

[xFuZzYx]

Are you serious with that video? The only thing i could tell from it is that you have a loud stereo.

it was the only video that i have of when the truck is running and the camera is somewhere where you can hear the noise lol, my bad.