[DivineCurrent]

Hey, so I have a budget for some headphones in the $500 range. I currently use mostly the Senn HD650 at home and the Klipsch X10 on the go. I really like warm sound with neutral non-emphasized treble like the HD650. So, I have been eyeballing the Klipsch X20i for a while, and they are apparently a big improvement in treble extension over the X10s, so they are something I would be very interested in buying. But, I don't want to pass up the opportunity to try another over-ear headphone. Is there an open headphone that is a similar sound signature to the HD650 (besides the HD600)? Maybe something with better soundstage but not too different sound signature? I feel I would like the AudioQuest Nighthawk purely by looking at graphs, but graphs don't always give you the full story. Any suggestions for open and/or in-ears that are warm but not too recessed treble?

 

[cskippy]

If I may, you might want to consider putting that money towards a better amp or DAC.  A Vali 2, Valhalla 2, or possibly used Crack+Speedball would give you some tube goodness and give you a much better soundstage compared to solid state amps.  
 
If you're set on getting a new headphone, the HE-500 is hard to beat, especially for the money.  I haven't heard the Nighthawk but looking at the graphs and people's opinions I trust, they lack the mids that the HD650 are known for.  

 

[DivineCurrent]

Yes the Hifiman headphones do have raving reviews, the HE-500 is slighty over my budget but the HE-400i looks great. Are the HE-400i significantly brighter than the HD-650?

 

[cskippy]

400i have a U-shaped sound compared to the HD650 but also have a slight treble peak at 9lHz.  Not sure if you're treble sensitive but it's something to keep in mind.
 
Here are measurements I took of each:
 
HD650

 
 
HE-400i

 
 
Don't compare my measurements to others.  These are just for comparison sake.  I would personally find a used HE-500.  I might actually be willing to sell mine with Jerg Pads(these improve the midrange dip of the stock pads).
 
HE-500 w Jerg Pads

 
Let me know if you have any more questions.