rgbManiac

I also had this problem, after a fresh install of windows it just *poof* went away.

drop it again & everything might even out

Only thing mechanical in the average PSU is a fan...so unless you have a pet roach with a mini crowbar messing around in there, you're probably going to want to RMA the PSU due to a failing fan bearing or something like that.  Just make sure you don't have a loose molex connector or something like that drooping into the vent slightly that could cause the noise when the fan blades hit it before you go calling the PSU manufacturer.

It might fail soon, unfortunately. Sounds like the fan has gone bad. You should RMA it if you can, you don't want to mess with power supplies. If you are really brave, you could open it up and replace the fan with a new one, but it is very dangerous to do.

do some cable managment, lad.

I've never heard that happening nor think that could happen.

Okay just making sure you didnt have a Super hot build or anything (1080ti or 8700K for example)
 
The Cheap version of the Meshify C is the Focus G. Comes in 5 colors and has 2 120mm fans for about 45 euro on amazon.de (assuming you can use that)
https://de.pcpartpicker.com/product/ZHmxFT/fractal-design-focus-g-black-atx-mid-tower-case-fd-ca-focus-bk-w
 
Coolermaster also has the MB500 if you're looking into RGB, a PSU shroud and TG
https://de.pcpartpicker.com/product/6qPKHx/cooler-master-masterbox-mb500-atx-mid-tower-case-mcb-b500d-kgnn-s00
 
The MasterBox 5 is also a good platform for future upgradability
https://de.pcpartpicker.com/product/jcH48d/cooler-master-masterbox-5-black-atx-mid-tower-case-mcx-b5s1-kwnn-11

If you're worried about that, you shouldn't be skimping on the PSU, tbh. It'll be louder than some higher quality unit as load increases, yes. How loud? No idea, I don't have any CX units.
 
Other components are likely louder than the PSU in any case.