I disagree having my 1x 140mm on an archon running a Q6600 at 3.6 ghz at even 1240 rpm nevermind undervolted is very quiet.
And yes I can compare it to a very low rpm and noise level 120mm fan.
You guys are talking about people with 2x noisy high rpm 120mm fans on a heatsink and case fans.
I have compared 2x120mm fans at 5v and there's virtually no difference in noise level compared to a single 140mm at around 1000rpm.
Oh and my gpu is always very quiet too as I normally have a low rpm fan and aftermarket cooler on mine.
I never said air cooling is better I was more saying the noise levels aren't such a massive difference these days with the right fans and heatsinks.
btw those akasa fans are actually considered noisy (especially noisy on an h50) so no wonder it's a huge difference to your ears.
I don't think the big noise gap is there any more and I am pretty sure you'll need a bit more than a couple of fans at 500rpm to cool a whole rig at a high overclock.
im sure u have more than 1 fan cooling the CPU thou
most likly u'll have 3, 1 on the heat sink, one intake into the case, and 1 exhust
the fan on the heatsink alone wont be able to keep your system cool
with watercooling, ur not replacing a single fan with the rad, ur replacing all fans