I believe they are modded.
They're highly modded. I've worked on these bloody things on and off for the past 2 years. Custom damping and I drilled all those holes in the back of the cups, and added the headband padding and tension support beams I also made the YH1 open back.
Very cool to see the FR! So the slightly grainy/rough sounding treble is actually just a lack of extension. I tried sooooooo hard to get it smooth, but the only thing you can do is create a peak, the driver just won't put out more treble extension.
This is all fascinating. Thanks Marv!!!