Correct, these are just aftermarket pads. The quality is good, pleather is soft and doesn't irritate even with extended listening (had them on for 4hrs straight last night). The padding itself is a bit stiff initially but even after 4hours they've become softer or conformed. As for sound, I'm somewhat fighting a head cold at the moment so I wouldn't trust what I'm hearing. However, the bass has more impact with the pads it seems. More than even HF non-angled pleather. It does sound a bit like it's bleeding into the mids but this could be due to the lack of venting. I might try a back vent opening mod, similar to Jerg pads to see if that takes the bass away from the mids. Again it's not drastic but with certain songs with the mid-bass emphasized it encroaches into the mids.
I wonder how those same pads would sound on my W1000x?
I'll know soon enough honestly. I'm getting new pads onto my D2k and I'll have the old OEM pads to test
but man that L3000 Leather feels so Good! Not sure If I can part with it :3