best 120mm Fan for Ultra low sound?

[teraformer]

I got 8x 120mm Thermaltake fans and there priddy quiet
but im sure there must be a fan out there that"s even quieter? Any suggestions folks!:confused:

 

[Pimp]

Yeah mate i have used this in my case but the 1200rpm version not 800rpm

Noctua NF-S12 800RPM 120mm Silent Case Fan - 3 Pin

- 12v performance - 800RPM, 8dBA, 35CFM
- 7.5v performance - 500RPM, <5dBA, 20CFM
- 3 and 4 pin power connectors

as you can see on 7.5v - 500rpm is 5dBA but only moves 20CFM of air which TBH is not really that good i got the 1200RPM version:

- 12v performance - 1200RPM, 17dBA, 48CFM

much better in moving air but a lot louder then the 800RPM but compared to other fans out there no other can compete with this :) unless you can show me one that's better :P