Yeah, I don't know why they set it so high by default. It's just too whiny and high-pitched for this type of under-the-TV use at that level.
The setting you need to tweak in BIOS is the % Duty Cycle. Cryptic, I know, but this is what controls the minimum fan speed. Set it down to 20% from the default 40% (and then reboot). It will then run about 1800 RPM or so avg, and anything under 2000 RPM is virtually silent unless you have your ear right up against it.
You do so at your own risk of course. But my CPUs run at a steady 40C avg at 20% duty cycle, which is just fine IMHO.