Help with a complex procedure.

Hello everyone. I need help with a certain type of procedure.

I want that when I'm wearing an armor piece with a specific enchantment and I'm in a radius of 30 blocks, any entity who dies drop more experience.

But I have a problem : Either I have to define the player as a source entity, so I have to kill the entity myself to have more experience. Or I have to define the player as a target entity, so it works only when I'm the entity killed. 

I have tried to do a procedure that detects me in a radius and automatically makes any entity who dies drop more experience, but it does not work.