Hi, I'm in the market for a great, long-lasting pair of full-size closed headphones. I've been browsing the Head-Fi forums for a while now and have gotten quite a lot of great information (thanks!). After demo-ing a few models at a local pro-audio store, I'm left with a few questions that they (at the store) couldn't really answer. I should probably mention that I'm not an audiophile but I do appreciate sound clarity across the spectrum. Also, I intend to use these headphones for various activities: music listening (mostly electronica but not limited to it), movie watching, and some mixing (hobby)... in other words, they should be more "fun" than "balanced". My budget is 500$ give or take. So here I'll list my impressions of the various models I've demo'd and used in the past, and I'm hoping this would be the best way for you guys to come up with ideas and suggestions on what I should be looking for. Koss TD55... First decent cans I've ever owned, about 12 years ago. Not sure on the exact model number, but anyway, these were my first love. Definitely not head-fi material, but to put things in perspective, after they broke I've always wanted to find headphones with bass that rumbles as much as these did. And I do mean rumble... it was like a mini massage chair for my ears. Sony MDR-V150... After trying to find a decent replacement for my Koss, I settled on these because they had a decent amount of bass (I'm a bit of a basshead if you didn't pick that up already) while the presentation wasn't completely garbled like most other models I'd tried then. After a while I forgot about the Koss, and I must confess I actually liked these very much. Bose TriPort... When I demo'd these about 4-5 years ago, I was very impressed by the isolation, sound clarity and separation, and by the bass and especially the sub-bass. They didn't rumble as much as the Koss, but the overall sound quality (much higher than anything I'd tried thus far) had me buying them on the spot. They lasted me until recently, and now I'm looking for a replacement that sounds as good if not better. Dre Beats variety... Yes, I figured I'd try them on just to see what the hype was about. They didn't stay on my head much longer than a few seconds. Here's what wasn't bad about them: bass quantity, and looks. Everything else was sh**. Now if I could find some headphones with that much bass, but with the whole spectrum being as clear as my Bose were, I'd be happy. Bose AE2... Obvious choice, at least for a test-drive. Their presentation is pretty much the same as the TriPort, but they don't isolate as much, and that's a downgrade for me. They're not as comfortable either, as the TriPort basically snugged my ears while these just frame them. Also, possibly due to lesser isolation, I find the bass to be slightly less impressive than in the TriPort. Beyerdynamic DT-770 Pro 250Ohms... That's where my demo adventures started at the pro-audio store, and my first time listening to true head-fi material. Now, you should know that I was testing this (and all others below) with my iPhone, amped by a FiiO E7. First impression: holy cr** the sound is clear! Second impression (after cranking the amp to max volume): holy cr** the volume is low! Obviously I had to try the 80Ohms version to get the kind of volume I'm interested in. Beyerdynamic DT-770 Pro 80Ohms... Ok, now we're getting somewhere. I really love these, and at less than 200$ it almost feels like a steal. The only thing that kept me from buying them outright is this: the bass doesn't rumble. The bass is great, I hear it better than ever, but I don't feel it. If I'm never gonna find headphones with rumbling bass like the Koss, these would be my first choice. Now, I realize that maybe the lack of rumble might be due to the high impedance which would require a much stronger amp than a FiiO E7 to get the drivers shaking. If that's the case, then I should probably look into lower impedance models. I'd very much like some input on this. Sennheiser HD25... Can't remember the exact model number, mainly because I wasn't impressed by the overall presentation, nor was I looking for on-ear headphones. But I had to try them, as I'd never tried closed Sennheiser cans before. Good, but not impressive enough. Ultrasone Pro650... I had read a lot about Ultrasone on these forums and was looking forward to try them on. This quest for head-fi basshead cans actually started with me reading a Dre Beats customer review stating that the Pro900 would re-educate anyone who thinks Dre Beats bass is where it's at. The store didn't hold Pro900's, and to keep it short, the Pro650 were disappointing. Not enough bass, not by a long shot. Overall sound quality was good, though not as good as the DT-770 Pro. That's my story so far. With all this info, I'm hoping some of you could answer the following questions for me: Would the Ultrasone Pro900 produce bass that rumbles my head at decently high volumes without killing the rest of the spectrum? How clear is the sound in the Pro900 when compared to the DT-770 Pro? I hate sibilance, and some people seem to experience it with the Pro900; personally I thought the highs were perfect in the 770 and a little too strong in the Pro650 I demo'd. Would the bass in the DT-770 Pro actually rumble if I used a more powerful amp than a FiiO E7, EQ or not? I read about the Denon cans being great for bassheads... given all I've said, should I look for a store that demo's them or has a lenient return policy? Or is it obvious they wouldn't sound right to my ears? What about the AKG K550? Reviews I read on these forums seem to imply that I should try them before making any decision. Would there actually be a Koss model with that rumbling bass I'm so obsessed about, but also with the kind of sound clarity found in the DT-770 Pro or even just the Bose TriPort or AE2? Thanks so very much for taking the time to read my wall of text and helping me make the right investment. Cheers!