Originally Posted by The Pook
I like my two industrial Noctuas. They're obnoxious at full tilt but I rarely run them at more than 20% and they do more than fine.
I would have went with the NF-A12X25 but since I couldn't put up with poop brown in my system I went for the industrials.
I have 2x140mm 3k rpm industrial noctua. They're silent till 1500rpm, above that noise gets noticeable. Also my both fans were maxed out at 2640rpm (they advertise it as 3k rpm). Even replacement fans were same. If OP wants high performance, then these Noctuas are not worth their price. In my country price of USED gentle typhoon / similar delta fan costs 4-5 usd.
If OP want lowest noise + good performance @ under 1500rpm , then nothing can beat Noctua industrial fans when run at slower speed. If you do push+pull on a 480mm rad, then noctua setup will cost 8x27usd = 216usd lol.