Anyone in search of the Auvio 6-foot cable, I will sell you mine at cost. I tried it out today, but it seems to really increase the harshness of the highs. I spent all of 10 minutes at Radio Shack and $3 at the register, so worth a try. Just not an improvement to me. Just PM me if you want the cable.
Right now, I am happy with the stock ML90s and the stock cable. I actually like it with just my HP out on the iPhone 5, using the Onkyo HF EQ app (a slight bass tweak). I am at 40 or so hours of burn in and not changing much to my ears. But will let them on for 60+ and see what happens. I like them, great value at $68. But just not up for modding them. Worried I will destroy them or at the very least, make them sound worse. So to me, they are not going to replace the Fidelio X1s any time soon as my home phones. I'll use both, try and see if the ML90s are better with some genres than others. I also prefer the X1 fit, of course, but that's a no brainer.
Make it 80+ hours to be safe. You should notice a change by then. How are you burning them in again? I had some bass and drums tunes beating them at fairly high volumes (but not high enough to destroy anything).