I strongly favor IEMs for portable listening, since I'm a runner and nothing works better, but now my listening appetite's been whetted and I want to start improving my home setup. Off a PC, I'm running a pair of old, old Sony MDR V6s through an old, old Go-Vibe amp (the one that takes 9 volts) and I'm not unhappy, but I wonder whether there's more I could be doing. Assume a budget of $100-$150 per component. I'm now playing 320k mp3s, but will transition to FLAC soon enough. My listening habits are eclectic, so genres are probably unhelpful: classical, jazz, blues, soul, rock (punk and metal), reggae, hip-hop, electronica, and DnB. Sound qualities I need: Bass extension: it doesn't have to be loud, but it has to be present through the full range. The extension of the V6s falls off a cliff at around 55hz and it drives me batty, because a lot of my tracks have energy there and it sounds plainly wrong to have that energy go missing. Accuracy and speed: If you're pardon the IEM reference, one of the things I fell in love with in my RE0s was it's ability to handle high frequency transients smoothly. When listening to high-frequency percussion attacks--cymbals, high-hats, snares--there's a layer of stick-on-drum detail that I won't do without. (Please, please don't let this cost me a car payment.) The RE0s also taught me about soundstage, and it's fun but not a dealmaker. I'd pay $25 extra for it, maybe, but not $50. If it helps, my impressions of my current rig are moderately positive. As long as you don't drive the music too deep or too fast, it sounds good. Moderate soundstage, with a bit of pleasant airiness, they're good-enough phones. My question, then: What is my upgrade, and what will it cost me?