these headphone bring together the best of two world : high-end , audiophile sound and portable music player . I be very particular about the quality of sound , and before I audition a friend 's 595 , I have assume that I would need a headphone amplifier to be able to drive the anemic amplifier in my portable music player . as most of you know , pmp be build for portability and simply can not accommodate large amplifier , such as the one that exist in home music system . unfortunately , most audiophile headphone be design with a high impedance -lrb- or resistance -rrb- , such as 300 ohm . while these type of headphone be perfect for home receiver or amplifier , they make pmp unlistenable because even at maximum volume , the pmp do not have enough wattage to drive these headphone . imagine , then , my surprise , when my friend tell I that the 595 have a impedance of only 50 ohm , surprisingly efficient for headphone of this quality . I be able to plug they directly into my pmp -lrb- without the need for headphone amplification -rrb- and listen to glorious sound at volume level that would suit any hard-core rocker . the 595 come with two jack -lrb- a 1\/4 '' jack for home receiver and a 1\/8 '' jack for pmp . -rrb- they be comfortable to wear for extended period of time and they produce stellar sound in all genre . they reveal excellent detail in music , they reproduce bass , midrange and high without coloration , and they have a excellent soundstange . as evidence of they soundstage , one can identify the venue of a recording and easily place the perfomer in that venue . -lrb- while listen to a Radiohead album , I be immediately place in a recording studio , with the musician in various part of the studio . moreover , while listen to a fine chamber music recording , I be immediately place in a small concert hall and be able to pinpoint the musician there as well . the 595 also faithfully and accurately reproduce surround sound from well-recorded movie . -rrb- it be rare for I to review a product and not find any fault , but this be the case with the Sennheiser hd-595 . and since they be introduce several year ago , they price have be substantially reduce and be now under $ 200 . they be a audiophile bargain .