Yo dude, your not going to get the most out of those cans unless you amp them and eq them. Now that I know that you are using those cans with your phone, it makes my recommendations simple. You need to get a Fiio A3, which is going to be your amp, its battery operated and the battery will last all day of use before it needs to be recharged by USB. As far as EQ, I would recommend Power Amp, which is a music player software with an EQ modual built in.
When you go to EQ the cans with Power Amp, you want to raze everything bellow 100 hertz to plus 10DB. And you will want to raze everything at 8K to 16K to plus 10DB. And raze 2K to 6K to plus 5DB. And you might have to lower your Preamp slider but maybe not, it depends on weather you hear distortion and or crackle, if you do, lower the preamp slider, if not you can keep it flat. And keep your phones volume around 70%, razing any higher could cause distortion due to the poor DAC inside.
Basically you will use the Fiio A3 Amp as a volume adjust, cause it has a volume knob on it for the power. You will want to turn the bass boost ON, on your amp, and you will also want to turn on the HIGH gain. These settings should really help you to open up the cans. Remember these cans have burn in, so don't push them too hard for the first 30 hours of use. Then after 30 hours, crank them up to vibrate the crud out of your skull. And then after 300 hours, the cans will be fully burned in and will sound better then they did when you bought them. Hope this helps!
EDIT: Just realized that I read your post wrong and you already got the E12 which is an even better portable AMP. Apologies, everything else regarding EQ still applies, as well as settings on your AMP.