Noise control and cooling

[Novirius]

I had 3 different systems, but the latest one is loudest even though it shouldn't be:

 

1. Corsair Air 540 (i7 6700k)

- 2x 140mm fans pulling through front radiator (Stock fans)

- 1x 140mm fan pulling through rear
- NZXT Kraken x61

 

2. Corsair 4000d (5600x)

- 1x 120mm fan in front (No rad, Stock)

- 1x 120mm fan in rear (stock)

- Arctic liquid freezer II (stock fans, top exhaust push)

 

3. Corsair 4000d (5600x)
- 3x 120mm front (No rad, Scythe Kaze Flex)

- 1x 1200mm fan rear (Stock)

- Arctic Liquid Freezer II (Stock fans, top exhaust push)

 

Why is the third system the loudest? I thought that it would run fans at lower rpm and be more silent than the other two systems? Even during idle, it feels like it's ridiculously loud. The front fans are supposed to be an upgrade as well given reviews about its silence and CFM. The TDP is actually reduced as well.

[Novirius]

Solved. Turns out the PSU was the culprit (Yes, I know there were lots of factors). Eco mode is necessary for Super Flower PSUs if you dislike blaringly noisy PCs.