The first thing to consider is that the db rating doesn't tell the whole story. Tone, resonance and other factors can be more important than pure sound levels and in this is particularly the case with the Noctua's.



Motor whine and rhythmic speed related clicking may not show up on the sound meter but they are very apparent and can be annoyingly intrusive. On the flip side you could have a fan that made no discernable whining or clicking but was 'showing' as rating high on decibels!

These Noctuas (with the exception of the NF-S12B FLX @ 12v and LNA) are definitely in the 2nd category. Their decibel ratings put them at the higher end of the scale when compared to the majority of the fans i have tested and yet they delivery such a buttery smooth sound signature that they simply blend into insignificance.

Despite the readings i got (triple checked) i would say that these were some of the least intrusive and quietest fans i have tested.

The NF-P14 FLX - a big fan with a big performance. It was quiet at all voltages - no motor whine or turbulence style chuffing even @ 12v.

By the time i got to the ULNA cable i would say the fan was virtually silent. Due somewhat to its sheer size it also provided decent airflow even at lower fan speeds.


NF-P14 FLX.

The NF-P12 offers great silent performance at virtually all voltages. It's not the master of static pressure but it provides a decent performance at stock and using the LNA. When the ULNA (and LNA/ULNA combo) is applied it's deathly silent but a bit weak on the pressure side.


NF-P12.

Finally the NF-S12B FLX is a true power fan. It's static pressure performance is considerable but i would say it's sound is somewhat intrusive @ 12v and noticeable with the LNA fitted.

That said, at all the reduced voltages it did very well. Indeed, i was simply gobsmacked at how well it did with the LNA/ULNA connected in line... i'd guess it was spinning at around 400rpm while still providing acceptable pressure. Would be perfect for a HTPC or silent PC project.


NF-S12B.