I just got these today. I've been looking for a good sounding, but good fitting ear bud since I started working out. I've been searching a lot, and the biggest issue is finding a pair that both stayed in my ears well with good comfort and that also sounded good.
I got these koss today and I have to say that I was really happy with the sound. Like someone else said, they sound like the porta pro. I'd say their sound is a little more "boxy" than the porta pro, like the sound stage is much more contained. I suppose that's because they are ear buds rather than an actual pair of headphones. But things like drums sound a bit "cut off", as though they don't extend enough. However, the balance is really good, and the detail is actually quite clear, even though these seem to try to create a mixture of sound, sort of like something with actual sound stage. But it doesn't reduce clarity. They work well with all types of music, and get loud enough. The overall quality of sound seems spacious and natural.
I was initially disappointed with the fit, but I decided to take them home and mess with the ear tips on them. The thing is, I have accumulated a couple of very cheap pairs of ear buds in my quest and one of them was the JVC marshmallow, which had the memory foam tips. I didn't take the JVC back since I was thinking that it was the best I was going to do with the sound/fit/comfort ratio for the money.
Anyway, I put some really thin bands of electrical tape around the part where the tips go over the speakers (so as to stabilize the memory foam tips, otherwise they would slide around on the housing), and widened the marshmallow tips enough to put them on the Koss. They work perfectly...they stay in my ears so easily now and they isolate like ear plugs. I also noticed a little bump in the bass after doing this, but it isn't too much. It's probably not as much as with these so called comply tips I hear about. But the electrical tape around the speaker housing does its job, as the memory foam tips don't rotate around on the housing, and they aren't so narrow as to not allow the sound to leave the speaker uninhibited. I can wear them for a long time and be fine with them.
I'm very happy with these, although I sort of think that I should not have to rig the ear tips to get them to be ideal. Anyone know where I can get some replacement JVC marshmallow tips?