If you have the itch to try something new, use EQ. If you want to get something simple to EQ the sound to another headphone, use the Morphit plugin on USB Audio Player Pro. Worth every penny and that app is the best one for playing lossless files.

You can use it with your HD 560S and Sundara (as they are both on the Morphit list). I use it all of the time and it is worth it. There is a trial for it if you are interested.