I just send him a PM.   I'm interested in this pads.   Thanks guys!

    I'm going to buy it from this website, I live in Europe, so the shipping costs are reasonable for me.   http://headphonespares.sennheiser.co.uk/hifi-tv-headphones/hd-650   As you can see, the HD650 is cheaper (I don't know why)   £ 7.88 HD600 Headband padding   £ 6.91 HD650...

Thanks for enlighten me!   I've seen that other mod with Senn headband, it's easier and looks nice.   The question now is about what Senn headband should I buy, the HD600 headband has some bumps in it, and the HD650 has only two big bumps on the sides.   I'll probably buy both headbands...

 Looks great with the Beyer headband.   I have a HE-400 too, and I have a really small head, ¿does the beyer headband fit properly?   Thanks for the idea, these is what i'm looking for.   Regards from Spain!