How noisy are Lian Li fans compared to other aftermarket ones? I'm considering replacing the two stock ones, but don't know how big a difference it'll make. I have a PC-A09.
Good/low cost solutions would be a pair of low speed Yate Loon 120mm fans. Get them from Petra's and you'll get two very high quality fans for $10 + minimal shipping.
They will be significantly quieter than the Lian-Li fans, especially when undervolted.
I second Yate Loons. I replaced the 2 stock 120mm fans in my Lian Li PC-A05B in addition to the stock fan in my Tuniq Tower with a couple of low speed Yate Loons, and have noticed no change in temperature, but my computer is now indistinguishable from ambient noise.
I bought my fans from yesbuy.net OEM for 19.99 and free shipping for a 4 pack.
The LL stock fans aren't as low noise as some, but then they put out about 25% more air than many OEM fans. Plus they are ball bearing, so they should last. It was tested in the first 120mm fan roundup in the forums on XtremeSystems and Vapor didn't much care for it. I've got a Rocketfish here running three of them full speed and it's not too bad. I'd probably go with Scythe Ultra Kaze medium speed f/r on a controller. Those should be a good setup.