“I bought my first set of 8320 two years or more back. They were very flat in the beggining then someone sugested these should be burned in for a few days with white noise. An old cell phone and white noise generator helped break these things in. Man o man what a difference. Made my bose IEM look like dollar store headphones. Sound is a relative thing IMHO just like taste in food. Some like...” --engineerd3d
“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 making them easy to fake. (In fact my first pair were fake!) these earbuds sound GREAT! Especially considering the price ($44) I have a few pair of earbuds in this same and higher price range and these PK3's knock all of them out of the water. They have a flat sounding...” --thebluebulk
“I purchased these a long time ago after reading reviews that these were a good budget option in the earphone category. To save time, i am just going to jump in to the sound quality section.. Bass: A little bass light for my tastes, but i can live with it. I doubt people are going to complain with these at the price they are offered at. It has decent punch to it, but like i said, a...” --zach8278
“ These were my sweetest sounding head-gear yet. It would be brilliant all-rounder if it would not require a portable amp for portable use. This is the first reason i left it, otherwise i almost got an ear infection from those foams.., they get dirty in a few weeks of massive use. I recommend them to clean, i boiled them in water. ” --angevoi
“ Well firstly this is not a true iem. The sound is about as great as one could get from an earbud. In my limited experience and without trying the pk1, I would say these are the finest buds you can buy. With that said, these are not for everyone, this is a niche product within an already niche market. I find driving it with my D12 anaconda makes for a pleasurable sound,...” --Jamesdeandoa
“ Overall I have been satisfied with these phones. I would not recommend paying full price for them like I did. ” --Skoch
PK2 earphones are the low impedance version of PK1. Although not as good as PK1, PK2's sound signature is similar to PK1. You don't have to drive PK2 with an expensive head-amp. If you are looking for something with high performance/price ratio, PK2 might be the best choice.