Originally Posted by nathan
There the Koss KSC75 which are about half the price ($15 on Amazon right now) of potrapros and have pretty much the same sound as they have the exact same titanium drivers. I have the KSC75 and I really enjoy them for exercise. Great clear sound with decent frequency extension. I haven't listened to the potrapros but I believe from what I've read that the KSC75 in comparison have a slightly less boomier base, slightly better treble, and slightly more airier/open sound do to the KSC75 more open design.
The Porta Pro does not use titanium drivers so the KSC75 actually potentially sounds better, depending on what you like. The titanium drivers have more defined treble but the downside is that they can be a bit harsh (and have some of that 'metallic' sound signature). The Porta Pro does not have as much clarity in the treble but it has a more pleasing, bass-driven sound signature that some people prefer. Best to audition them both before buying.