Fan noise (Buzzing Sound on low RPM)

[angelion]

Hello everyone i got AEROCOOL SHARK FAN DEVIL RED EDITION 140MM using a fan controller i can adjust in 3 speeds the fan everything is fine exept tha when i use the LOW RPM mode i can hear a buzzing sound coming from the fan even if is top the blades the mechanical buzzing song wont stop.... any idea whats going on?(i also used another fan on the same controller and no problem at all

 

[Mr5oh]

Is it mounted vertically, or horizontally?

 

[angelion]

It's horizontally as an exhaust fan

 

[angelion]

I want also to try the Volt Reduction cable included from 12v to 7v to see if the sound will remain..

 

[Mr5oh]

It's horizontally as an exhaust fan

From what I found on Google that uses a fluid style bearing, and fans with those types of bearings can make noise at various RPMs when mounted horizontally.

I just had a similar problem except it was a clicking sound on one of my Cougar fans when at full speed. Slowing it down made the noise go away.

Fans with fluid bearings aren't ideal for horizontal mounting.

 

[angelion]

Thanks mate i am gonna try use it vertically and see the diference