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.
“ 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
Portable Isolation Earbud Stereophone
Noise Isolating in-ear Stereophone
SportBud headphones by Koss are molded in the colors of your favorite NCAA team, including their collegiate logo This 2 pair pack of ultra-lightweight in-ear SportBuds is perfect for music on the go You get both home and away colors This dual portable stereophone unit includes a see-through, compact, wind-up spool carrying case for easy storage and protection when not in use 4-foot straight...
“ Overall I have been satisfied with these phones. I would not recommend paying full price for them like I did. ” --Skoch
The KEB70 is a high quality aluminum isolation earbud that delivers accurate acoustic reproduction in a compact and comfortable design. The KEB70 features a dynamic element that is positioned just outside the ear for extended frequency response. The KEB70 includes small, medium and large silicone ear cushions for a customized fit to enhance isolation when you want to eliminate ambient sounds...
The KE/29 is lightweight with an in-the-ear design for deep bass and listening to music on the go. The KE/29 features a dynamic element that is positioned just outside the ear for extended frequency response of 15-20,000Hz. The KE/29 includes small, medium and large silicone ear cushions for a customized fit to enhance isolation when you want to eliminate ambient sounds that interfere with the...