They are not the same. They're a little warmer, a little more mellow in the sound signature. They're also a bit lighter, a bit more comfortable, and a bit easier to drive. the HD500A has 150ohm impedance and these have 50ohm impedance. They'll work on a smartphone, for instance, where the HD500A may struggle a bit on a portable device. In terms of which sound "better", that's a matter of opinion since we all hear sounds differently. These kind of roll off the treble and boost the bass ever so slightly (it is NOT like a beats competitor or anything). Hopefully that helps!