That is until you try something like Stax. It is all a matter of perspective, really. They are relaxed and a bit dull compared to my stats. But I can perceive both as fairly balanced, depending on what I am used to at the moment. Even though I havn't come up with one thing they have in common... Like at all
Source or not, the HE-500 will always lack some depth. I find it to be somewhat adequate on most well recorded tracks, though. But a good source really does make a difference in my opinion.
They don't sound dull or relaxed with the Emotiva behind them. They sound aggressive and fast--the speaker taps really add to the dynamic range on both ends, making them sound more explosive and fast.