Hi,
I have CCR-1009-8G-1S THAT makes fan noise so much in the home.
So I tried to change the fans as silmilar with original fans but it didn’t worked.
Also, I tried to attached rubber gasket to the fans but the noise didn’t reduced.
If you have the solution to reduce fan noise, please let me know it would be appreciate.
Yoon.
Cut the + wire and add a 100ohm resistor. Or buy those adapters from the picture.
https://www.quietpc.com/images/products/na-ds-acc-large.jpg
Or swap the fan. Or made a fan mod.
here is my ccr1036 on a wall board with custom fans. maybe not to everyones liking, but its quiet, cool, and processing 10gbps. 
https://www.dslreports.com/forum/r30537527-