Help identifying this sound

I have an 07 Dbl cab and for about a month or so now I've been getting a weird sound at highway speeds, starts at about 65-70mph. I noticed it after I put on some used bfg mud terrains(33's) I thought the tires were making this sound so I swapped out the mud's for some new all terrains but I'm still getting this sounds. It's like a loud hum similar to what mud tires sound like. I thought that it could be a hub bearing but it's a different sound than what a hub bearing makes when going out. here's a video, hope I can get some help on here

https://youtu.be/EfeKK6S3iuQ

 

Is it RPM specific?

Or road speed specific?