Pros: clear as a bell, the mids and highs are crisp and clean with good definition and separation.
Cons: lacking bass. bass is very distant and hollow.
Looking at the picture of the PK3's I wasn't expecting much. They look and feel cheap using a generic case for the drivers. First I tried them without the foam covers and they sounded awful. I originally thought I had been sold a pair of fakes but after using them with the full cover foams I am impressed. they have good definition and separation in the mid and high frequencies. The bass is there but its distant and hollow. I had heard that these had more bass than the PK2 and PK1 this is one of the reasons I bought these (that and the price :-) but I was very disappointed in that area. over all i think these are a great buy but not for the people that like a little extra bass. Using sansa clip + with rockbox.