Yeah, I go through phases of liking one or the other better, and when I need a bit more bass, the sporta pro drivers go onto the headband. I only have one of those parts express headbands, and it's half broken, so I need to score a couple more. The headband itself costs about $1.99, but shipping to Canada is $30US lol. Hopefully @carpman will be the "parts express headband saviour" lol: http://www.head-fi.org/t/638757/koss-ksc75s-dont-forget-this-giant-killer-in-all-the-hidden-gem-hype/630#post_11480209
For the uninitiated, the sportapro and portapro headphones (and ksc35 clips) use the exact same drivers, and they look the same but sound different (mainly bassier) than the ksc75 drivers. All of the drivers can be interchanged amongst the other's headbands and clips. Confusing but cool.