Here's a picture of the dimensions: http://storage.googl...P_3096492_en_v0
I haven't made a header for a channel in a while, so I'm not sure what the 'average' width for the desktop safe area is.
They also put your icon in the very upper left, at a dimension which I believe is 240x240, though I'm not entirely sure, so if you could slide it to the right and put black space there (the outside of my icon is black), then that would be great!
I really hate to ask so much, I've just been needing a header for a long time now. I don't have a ton of subscribers, but I will certainly mention you in a video and give credit in my 'about' section. Thanks again for everything that you are doing!
EDIT: Also, I only really care about the desktop area, I'm assuming very little people actually view youtube on their Tv's, so no need to add anything else above and below, just resizing