Hey guys, I've done a bit of research in choosing the right pair of headphones but now  I am stuck between the:
 Audio-Technica ATH-M50x;
 Audio-Technica ATH-M40x (is there a difference in audio?) ;

OR

 Sol Republic 1601-30 Master Tracks (heard mixed reviews)

 Or if anyone has any suggestions of headphones in the $130-200 range.

here's a useful site for comparing frequency responses of headphones. personally i use sennheiser HD598's and i like them a lot, they're ~$150, had them for 3 years or so. heard good things about  audiotechnicas too tho.

I was thinking of buying those and I also found a good deal on amazon for them. But I heard that those are better for acoustic rather than electronic music. Not sure if that is true or why.

I just got my beyerdynamic DT 990 pro's in and boy do I love them. They run about 190, I spent 210 with over night shipping on amazon. Great buy honestly, It opened the way I listen to music.

I can support the beyerdynamic DT 990 pro's as well, I've used them for mixing for many months now and were SO worth it.

I saw that your original headphone selections were all closed-back headphones. Was that on purpose? Have you considered open-back headphones like the beryerdynamic DT 990 Pro? If you are confused by the differences between open/closed back, here's a great article that describes it simply:

http://www.howtogeek.com/191416/ask-htg-whats-the-difference-between-open-back-and-closed-back-headphones-and-which-should-i-get/