Since no one's jumped in to help you, I'll give you my thoughts on the DT 440, even though I've never heard the HFI-580. The DT 440 is in my opinion one of the most overlooked headphones around, and I love it, but the Ultrasone is almost certainly better suited to what you want. I own/have owned numerous Ultrasones, and they are going to have more bass and be more engaging in general. The DT 440 has very nice soundstage, but the presentation is more on the airy and refined side. Plus they are not really portable, if that's a concern. They are large, open, and have a very long cord. Although I have been known to wear them around the house plugged into an iPod, and they sound great that way.