I need a SILENT fan. Can someone help please :)

Hi everyone,

So ive got a problem. 2 fans and $450 later Im still not happy with the fan I have.

So far I started out with a 6inch Silenced Hyperfan. I was not happy with the high pitch occilating whine sound like a jet engine.

So I threw it in the bin and got an 8inch Silenced Hyperfan, in hope to run it a lowest speed and not have any sound. Instead it also has a Whine noise, particulary at lower speeds.

I grow with a 315w CMH in a 4x2x6 wardrobe. I have acoustic ducting and a carbon...

I need a SILENT fan. Can someone help please