The TH-900s are an amazing headphone. It's a closed headphone, yet it sounds like an open one. The best sounstage in a closed headphone to date. It sounds great with any musical genre...it's an all-rounder. IIt isolates some, so wifey won't be bitching and moaning about the sound being too loud. The bass is miles ahead of the Denons. Treble is perfect. Mids a bit recessed, but just perfect for me. It trounces the ATH3000ANV (although this one has addictive mids) and Ultrasone ED8 (this is my go to portable headphone; I don't care about the bling factor drawing attention)...it's not even close. While most amps would drive these adequately, I've found the perfect one: The Hifiman EF-6. I originally bought it to drive the HE-6 headphones, but it failed miserably when playing large symphonic works (clipping and smearing). I was about to return the amp when I decided to try it with the Fostex and, voila, a match made in heaven. The sound is just sublime. You can listen for hours and there is no fatigue. Warm, inviting, addictive, euphonious, comforting. I've never heard anything better than Dire Straits and the Paul Simon Graceland album (i.e., wow, those African drums!) coming out of this combo. This could indeed be the headphone that finally covers all the bases...it does everything so well. I'm in love. Could the SR009 be better....it could, but right now I can't imagine anything being better than this. The EF-6 is a powerful monster, but I guess the Foxtex, for some reason unknown to me, thrives with a powerful amp. By the way, it also does rather well with the Burson soloist, but not as well as with the EF-6. Also does great with tube amps (i.e., wonderful with the Decware Taboo being driven by the CSP2 with mullard tubes all around; actually slightly behind the EF-6 in WOW factor). Right now this is my favorite headphone. It trumps all the others in my stable (i.e., HD800; T1; HE-6; LCD2; Ultrasone ED8; HD650; ATH3000ANV, AKG701; Beyer T5P; Grado RS1; Denon AD7000).