Please have a look at; http://www.youtube.com/watch?v=DI8T-K64LAY It seems an unfair test with the K3 filter settings much narrower than the 590. The 590 sounds noisier despite the extra S level. These guys seem to think its proof the 590 outperforms the K3, but I don't think it's a fair test. Comments? Adrian ... vk4tux