Just wanted to write about my experience with the Custom Gaming Interactive...yet another version of the COP/COPP. This version comes with a mic, a separate Y adapter and another cable. I've had these now for about a year and I loved them in the beginning. However, I recently came into a set of DT770 Pro's(250ohm). I also have a bit of high frequency hearing loss, so ymmv.
I find the DT770's as my new favorite between the two. Much better clarity and presence up top. Deep and impactful sub-bass with, to me, tighter mid-bass. A wider soundstage. The COPs, in comparison, seem to have a muddier lower end and far less clarity up top. I've opened Pandora's box up, and I can't seem to enjoy the COPs as much anymore.
With that in mind, I've found this page discussing some of the mods someone has success in:
https://diyaudioheaven.wordpress.com/headphones/measurements/brands-a-i/custom-one-pro/
So in short, I'll be purchasing the DT770 velour pads as recommended in that site (as well as in this thread). We'll see what that gives me first as I don't mind a brighter tone. If it's too bright of a mod, I'll start with the felt in the cups and see how that effects things...the TP behind the pads will be a last resort. I'll post up my thoughts when I've finished.