The funny thing is that the P190 comes with three separate case fans, and even with all three on low it's still audibly wheezing. But unless you have some really hot and bothersome parts in your case, all you need is one actually running. I disabled the one near the PSU and the one at the back, and left the one at the top running on low. So all in all I have the PSU fan (which either never moves or is totally silent, I don't know), the GPU fan, the CPU fan (which I can control with a dial at the back of the system, I have it on in-audible levels) and the top fan running. I can barely hear my system now! And all the temperatures are as low as ever.
Well, I can actually hear it from where I'm sitting, but that's only because I have been thinking about it. Compared with what I had before it's silent as the grave. Now I can hear the radiator from the fridge and other people in my building flushing their toilets, not sure that's an improvement.