Which case fans are best for air flow and lowest and smoothest noise

[Wolverine2349]

Which fans would these be. I have heard most Noctua are great? Are Be Quiet Silent Wings 3 really good as well or are they overhyped for air flow at low noise levels??? I heard Gamers Nexus mention they are quiet because they spin slower than others?? I did notice some new Be Quiet Silent Wings 3 I tried seemed to have more of a audible less smooth up and down annoying harmonic pitch hum at 1000 RPM and not just air flow smoothness low noise like 1000 RPM quiet fans should have.

Yet some older ones seemed quieter and smoother also at 1000 RPM. All were 140mm