As usual, the 4k ones don't have sound~
This is because exporting animations through Video Editing software after Rendering it in a Video format through a 3D Package compresses it further and loses quality.
To avoid that, I'd need to render it as an image sequence and render that out of the Video software (which is what I usually do), but unfortunately each of these videos, had I rendered them as image sequences in 4k *and* 60fps, would have been around 5GB average, which would VERY quickly take up too much space on my Hard drives ;v;
I hope that's okay <3