Your header area is 960×364 pixels but the image you used is 2830×1073. You can use this one which I’ve resized to 960×364 http://i.imgur.com/8Z04WG5.png It’s just 234kB which is a lot smaller than your original 5 MB image.
Thank you. I’ve replaced it with your version and it loads much faster.
Happy New Year!
Your site still loads pretty slow on my end. I’m still seeing the old header logo (bigger). Now, 2 images are being used. You should remove/hide the Background Header Image on Appearance -> Header. Then replace the Header Logo on Frontier Options -> Display -> Header Logo with the image linked on my post above. The one you used for the Header Background is a BMP and is 1.3MB which is still a lot bigger than 234KB.