[DiscoBurger]

So a few weeks ago I had to send my ultrasone pro 900s away because the drivers mysteriously stopped working. I use a fiio e17 amp and while I listen to music loud the gain is only set to 6db and I never turn the amp up all the way. I sent away my headphones because the bass was sounding tired and wornout...sure enough the drivers had to be replaced, they did it for free because it was a warranty problem and sent them back asap. When i got them back I excitedly put them on and found the SAME tired, lifeless, and shallow bass as before, these headphones sound about half as good as my d2000s currently. Do you guys think I just need to let them burn in, do I have to send them out again, or do I need to turn the gain up to properly power them? This seems like a really bad problem to have with such pricey headphones, but let me know what you think...thanks

 

[DiscoBurger]

now it sounds like the right ear has more umph than the left one..no doubt about this the Denons sound better atm and are half the price...whats happened?  

 

[KG Jag]

The Pro 750 needs a decent amp to produce the bass of which it is capable.  They even sounded bass light out of two Onkyo receivers I tried with them.  Be aware that they can be very loud and still not be properly driven.  Perhaps the Pro 900 has the same qualitites.

 

[AlfredWong]

While I never had thought the Pro 900 sounded good, I still would recommend running it in for 2 months (yes really) before giving final judgement. My experience with Ultrasones was that they require a notoriously long time to run in. Don't trash you cans with loud volume... I don't know but 6dB seems damaging to the cans and my ear.
 
D2000 is fun sounding.

 

[DiscoBurger]

Thanks for your advice you guys, I just keep reading about how the pro900s sound better then the d2000s..I know this is subjective, but these headphones sound seriously broken, I think the fiio e17 should adequately power them, or at least what I've read has indicated that. Also I know there is something to be said of burn-in time but the left ear sounds completely dead...and "apparently" the driver was just replaced....ugh