Installing Noctua 40mm fans in my router

To help reduce noise I've been wanting to replace the stock fans (Yate Loon D40SM-12C) that come with the HCiPC Router with something more quiet. I had to wait until I was able to move some services I was running on my dev server before I could do so. Fortunately, today that day came.
This is part one of my homelab re-organization project.
I decided to pick up two Noctua NF-A4x10 FLX fans as they came highly recommended. I can see why, from their quite overdone packaging to its contents, it really does feel quite premium. I still can't quite fathom why they went kind of overboard with the packaging (as ultimately it's just a couple of fans), but it certainly helps them stand out I suppose.
Packaging




Included you get a bunch of optional cables for various scenarios:
- A 30cm extension cable (NA-EC2)
- A "Low-Noise" adapter (NA-RC11)
- A 3:2 pin adapter (NA-AC2)
- A OmniJoin cable (NA-JC2)
- 4x Anti-vibration mounts (NA-AV3)
- 4x Fan screws (NM-SFS1)
Visual Comparison
I was surprised to see how much thinner (shallower?) the Noctuas are compared to the stock fans. Two of these Noctuas stacked on top of one another are almost the same height as one of these Yate Loon Fans


Installation
There are two fans installed within the router on the back wall. These are both connected by a Y-splitter to a single onboard fan port. I'll re-use the splitter for the new fans.


I decided to try the included "anti vibration mounts" instead of screws, as I'd like to try to get the router to be as quiet as possible, and rubber mounts seem like a more logical choice rather than directly screwing them into the back wall.



Make sure you check the bottom side of the fan which indicates which way the fans blow, so you don't accidentally install the mounts backwards. The thickest parts should be on the side that will be attached to the wall.



I decided to leave a bit sticking out inside and didn't clip the outside part at all. I might clip them later, but for now I figure it's not bad to leave them as-is in case I ever need to re-mount them or so, although I doubt that will ever happen to be honest.

Results
To be honest I wasn't entirely sure what to expect in terms of sound difference. Fortunately, the difference is immediately noticeable and the router is much more quiet now than it was before. You can still hear it if you're near it (and if it's not mounted inside a cage/closet), but there's no annoying pitch that came with the stock fans. Perfect.
I hope my brief overview may help you in case you are looking for similar improvements.
Thank you.
- Part 2: Installing Noctua 40mm fans in my router
- Part 1: HCiPC B203-1 HCL-SD525-6LA Router/PC Hardware Overview