Identifying noise source

Telecaster · 25 Jan 2015 at 21:15

I'm struggling to narrow down and identify the source of a fan related noise I'm getting.

I've tried different fans in the same case fan location and they always end up noisy after a certain speed, and it's not just wind noise it's like a slight rattle, hard to explain.

I'm wondering if it's either the case or the mounting style, it's a Lian Li case and it uses those same rubber grommets that you use on HDDs to slide them into mounting cut outs. You screw the grommets in and then slot the fan into it's mount in the top of the case.

Or I guess the other possibility is that it is air noise going through the vent, but it's like no air noise I've ever heard if it's that, it sounds more mechanical to me IMO.

Danny75 · 25 Jan 2015 at 21:30

Have you checked that the label in the centre on one of the sides isn't peeling off? That can make a slight rattle if it catches on mesh or something. But you say you've tried different ones so probably not the case.

Telecaster · 25 Jan 2015 at 21:40

Yeah tried different fans.

They're not noisy at idle, just when up to about 1250rpm+, fans that I've tried that all repeat the same/similar noise at or around similar speeds:

Corsair SP120
Scythe GT1850
Alpenföhn Wing boost

Tried same fans in a different location and they don't make any noise there, so it's something to do with the top fan location, but I dunno what :confused:

D1craig · 25 Jan 2015 at 23:09

could it be when the fans get fast they are sucking/blowing on a wire and making it move?

DavidS14 · 25 Jan 2015 at 23:11

Resonant frequency ?

If you touch the fan frame or the panel whilst they are making the noise does it stop or lessen ?

If it does this the you can change the frequency by adding mass/damping to the panel like you do in car audio installs with dynamat or using some rubber isolation mounts