CoolerMaster Silent Pro series.
I went with a 1200AX Corsair which was a bit oversized for my needs mainly to keep things quiet. I love it and it is very quiet.
Your HX1050 also has a large (140mm) relatively quiet fan but the more you tax the p/s, the more it needs to cool.
For example, 0 to 20% load = silent (fan is not even on)
25 to 50% load, pretty darn quiet (Corsair has a graph that shows around 25 db - just about silent)
Then, starting at 50% load and increasing up to 100% load they advertise the variable speed fan getting as loud as around 40 db
I can second the 1200AX. It's excellent and quiet
Second that, although in my specific case it would not matter at all. The machine is loud anyway with 18 fans and 25 mechanical disks inside, so I don't care. It is my work horse in my office, so nobody cares about the noise, and for voice-overs, I never do them in my office, but in a separate room with all windows closed etcetera.
In general, the higher the rated power of the PSU and the lower the actual power used (the more surplus you have) the lower the noise.
As far as I can tell, the fan of the HX1050 run is always running (though relatively quietly), regardless of load -- maybe because of the overall temperature in the box. When MB temperatures are 35C or so, it's hard to believe the PSU is going to be able to stop spinning, even if the load is under 1%.
It would be grand to know if your AX model is any quieter, but short of an A/B comparison, we'll probably never find out.
See the following noise curve from Newegg for the HX1050:
And here is one for the new, very configurable, and pretty expensive AX1200i (I have theAX1200 which does not have the user configurable load vs. fan speed capability):
So, let's say you are really pulling 450 watts.
For the AX1200i you would be at 37.5% load and from the chart, 10db (pretty darn quiet)
For your HX1050, you would be 43% loaded and from the chart at about 25db; every 3db of sound level makes a significant difference, so 15db is certainly substantial
Their charts show fan speed per load, but I'm pretty sure the fan speed is actually thermostatically controlled, so if the inlet for your p/s is getting warm air, it will be running faster for a given load.
My p/s is pulling air from underneath the case so it is the same temperature as the room. If yours is configured with the inlet from inside the case, then that air will indeed be warmer. For my Coolermaster case, I can choose which way the p/s is installed; your case may or may not allow for this mounting option.