“ I am lost for words for 2 reasons, 1st: These in ears behave much more like over ears headphones in all the good ways. 2nd: these deserve to be much more popular than they are, I am simply shocked that there is not much more renowned! I currently own the Shure SE535's as well as Sennheiser IE8 and have used and owned many of the 500 and under earphones, such as Monster Turbine Copper Pro...” --Tenor123
“ The PK3 is a great, warm earbud. It does vocals especially well because it is very mid-focused. It has impressive bass extension, not especially strong impact; the trebles are smooth and may roll off too soon for clarity and detail nuts. But the mids are what the PK3 are all about. ” --kmhaynes
“ 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
“ I love the full size grado HF2 and older grado's but these do not sound good to my ears. Strident and uneven. These were not lovingly crafted or dialed in. There was no 'man' behind the tuning of these and this is evident in the final product. I'd love to see grado come out with a smooth yet dynamic sounding iem similar to the HF2 but am not holding my breath, especially when I've found...” --thelostMIDrange
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.