Strange metallic ring somewhere inside case

[Solum]

As any person would know, noises that are out of the ordinary can be worrisome. As a worried new custom PC owner, I noticed something odd, and I'm unsure if I should be worried about it or I should just ignore it? I'm not quite sure what is causing this. It's definitely towards the bottom of the case, I just can't think of what would be the source, and what would be the cause. I'm thinking HDD? Unsure. You can hear it in this video (you might have to turn up your audio) it's like a sudden shift causing almost a metallic ring sound. Any help would be appreciated, thanks!

20180718_233924_1.mp4

[KarathKasun]

That would be the heads inside the HDD moving to do a read/write to the disk.  Its normal.

[Solum]

4 minutes ago, KarathKasun said:

That would be the heads inside the HDD moving to do a read/write to the disk.  Its normal.

It's just I've never heard it before on any of my past computers and especially so audible even with my case closed. If it's nothing to worry about then I guess I was just being a nervous nelly. Thank you man!