H150i Elite LCD - Adding case fans and controlling the fan speed?

[mtns]

Hi, I'm new to PC building/upgrading so go easy on me! I've recently receievd a prebuilt PC - case is the Fractal Meshify 2, with stock case fans 1 rear exhaust, and 2 in the top exhust. I have a Corsair H150i Elite LCD AIO, with the radiator installed on the front of the case. Motherboard is an ASUS TUF Z690-PLUS WIFI D4.

I want to replace the stock case fans with LL140s for some subtle RGB, and also to gain control of the fan speed. The OOTB fans are 3 pin, and from what I've read and understand these spin at a constant RPM, whereas the LL140s are 4 pin. So far I have 2 LL140s and I'm after some advice on installing them.

Currently, the stock fans (3 pin PWM, no RGB) are installed to a fan hub which came with the case (Nexus+ 2 fan hub) and this is connected to the motherboard via the CPU OPT header. I can see a couple of options to replace them with LL140s, but I was wondering about pros/cons of each approach, or if there is better way to do this.

Install the LL140s to the Commander Core, as there are 3 fans and 3 RGB ports free at the moment. I could then remove the Nexus+ 2 fan hub.

Install the LL140s, with the commander core controlling the RGB, and the fan control going to the Nexus+ 2.

I'm currently trying the options with the PC case open, and just trying connecting the wires for the 2 different configs and seeing what works best.

If I try option 1, connecting them 100% via the commander core, the iCue software detects the fans to config the RGB, but I can't see the fans in the software when I click on cooling - although they are spinning. How do I get control of the fan speed?

When trying option 2, connecting the fan control to the Nexus+ 2, again, the fans spin, but I'm struggling to get any control of the fan speed. In Armoury Crate FanExpert (which is what I assume is controlling the CPU OPT header?) it is reporting the min and max fan speed as around 2200RPM, and it doesn't appear to let me ramp them up and down.

Any advice would be greatly appreciated.

[c-attack]

8 hours ago, mtns said:

Currently, the stock fans (3 pin PWM, no RGB) are installed to a fan hub which came with the case (Nexus+ 2 fan hub)

You should leave those there.  The Commander Core in the AIO pack is a PWM only controller.  So yes, those 3 pin DC fans will run at a constant speed -- 100% max at all times.  No need for that.  The thing is that Nexus 2+ fan hub should be a PWM repeater.  If the fans connected to it are only 3 pin DC, then they don't belong on that either.  They need to go directly to the motherboard for control.  

 

All the LL fans are PWM and both their speed control wire and RGB wire can go to the Commander Core.  

Edited February 21, 2022 by c-attack