[ArrowMaker]

What I Have:
So, I've only owned the beyerdynamic DT 770 and 880s. The 770s were definitely bassy, as I've seen some posts implicate, and the 880s are pretty flat, or neutral, as I've seen on some posts as well. The 770s unfortunately broke and I have yet to repair them. The 880s are great for a pretty unbiased sound when arranging and mixing. I only use them every-so-often when I need to specifically polish some sort of detail. The 770s were great for hearing those lows and mid-lows that I can't grasp with the 880s when I'm trying to detail my work.  
 
What I'm Looking For:
...is something with a wide soundstage; clear robust bass that doesn't muddle or conflict with the mids or hi-ends. I make music with hip-hop beats and some rock with large drum sounds that are pretty hip-hop reminiscent. I like thumpy, poppy, kicks with a warm, solid kick, but with a nice thick undertone of sub-bass. I'm mainly use Abelton Live 9 on an iMac and I sometimes use an MBox2 to hear through. These headphones would have to be pretty well-rounded as I don't have a whole lot to spend. I ultimately want to keep upgrading my set-up as time moves forward, so I want something that reflects that movement. Further, I want something that is true to what I've created on Ableton, as best as possible. 
 
Over-Ear headphones are what I'm going for and I'm assuming open is better than closed? When recording open headphones pick up on the mic, but...that's not my top concern. The top two recommended are the Audio-Technica ATH-M50S and the Sennheiser HD 650 Headphones and I've also been looking at the Audio Technica ATH-AD900 and beyerdynamic DT 990s. I'm new to the world of amp-needed headphones and I'm not sure I can afford it. Any other recommendations would be greatly appreciated. 
 
I realize headphones aren't the main means of how one should produce/mix/master, but I love the intimacy of headphones and the fact that there's a huge market out there that mainly listens to music on headphones. I also realize that I need to get out there and listen for myself, but I wanted some experienced feedback as well.
 
Any questions about what I'm looking for, etc. in order for you to better help me out are welcome, for sure. Thanks for taking the time to read through this!

 

[xFairyxTailx]

Why would you consider the HD650 over the HD600?

 

[billybob_jcv]

I would like to know where the HD650 is under $350...

You might also consider the AKG line - the K701/K702/Q701

 

[pbui44]

Why would you consider the HD650 over the HD600?

He is not familiar that many feel that the hd600s sound more neutral than the hd650. I have the hd580 and prefer it to the warmer hd650, but that is just me.

If you use hip-hop samples a lot and you already have an open-back in the dt880, the ultrasone hfi-780 will give you great bass and everything else. My Pro 2900s are the best I have heard at combining quality+quantity+impact bass, and I have read here from someone suggesting the hfi-780s and not the pro 900s because of the "overly bright treble" and many pretty much agree.

 

[adupree]

I vote for the AKGs

 

[ArrowMaker]

Thanks you all. I invested and saved up for some studio monitors instead of getting the headphones. Though I'm still looking to get some in the future. Now I have a better idea of what to look for in the vast world of headphones. My only concern with the hfi 780s are the mids and the possible overall fatiguing of phones. I just hope the mids aren't too recessed or plastic. They certainly look like the direction I want to head down though. Thanks again and sorry about the delay in response.