I'm unsure whether to post this to the cases section or the fans section, since it deals with both. If this is in the wrong area, feel free to move the thread.
I recently built a system using the Fractal Design Define R4 case. After setting up drive suspension to cut a lot of the noise, I am looking to add in a few more quiet fans. 5V doesn't seem to cool my system well enough with the 2 pre-installed fans, and at 7V they're a bit noticeable but not terrible. I've currently got a rather old Nexus 120mm fan mounted in the upper front slot, but it is worn out or damaged and ticks. I need something there for drive cooling, and the poor old Nexus is going to drive me nuts. Sleeve bearing fans seem to start out quiet enough, but after 7 years of use they're considerably noisier. I'm trying to avoid them for now unless I can find massive noise reduction using sleeve bearings.
After reading the recently 140mm fan roundups, I have been looking at getting some Noctua NF-P14 FLX fans while they're still available. They have a round frame, and I am not sure if they will fit in the R4's fan slots. I'm particularly concerned about the 2 slots in the front panel. I remember reading that someone had trouble with round-framed fans and had to do some drilling (which I'd rather not do), but I don't know what type of fan that person was using.
Can anyone tell me for sure if I can put NF-P14 FLX fans in the front without any modifications? They seem to have holes to mount as 120mm with 140mm adapters, and the R4 has 120mm fan holes in the front.
I may also wish to mount a pair in the top sometime, but the R4 only seems to have holes for 120mm fans (or 140mm mounted with 120mm holes) but it looks as if the fans would be mounted too close together. The 2 sets of 4 mounting holes on top are not centered in the fan slot but pushed toward the middle (closest to the other fan opening), so that the space between one set of holes and the other looks roughly about 5/8th of an inch apart. I don't know if this would be enough space to mount 2 NF-P14 FLX fans. The R4 IS listed as being able to fit 2 140mm fans on top, but I can't quite see it happening unless it's with square-framed fans. Can anyone advise me on this as well?
I'd appreciate any help.