These are pretty solid cans, especially if you're a fan of electronic music as Sol Republic (a company I'm a huge fan of) has pretty much tuned their cans for that exact genre, as can be seen from their overall sensibilities with marketing, etc. Don't let that statement fool you though, these aren't boom-tastic basshead cans like say the Beats Solo HD or something along those lines. With their "Ultra" version of the popular Tracks line Sol Republic has toned down the level of bass while still making it more tight and high quality and cleaned up the higher registers in an attempt at audiophile territory. Did that attempt pay off? Well, sort of.
 
First of all, if Sol Republic was targeting die-hard audiophiles with this headphone, their going to be in for a disappointment. These are not going to blow the socks off any audiophile who has heard anything from, say the Sennheiser HD line, but they may wow more average consumers who's reference points are Beats or Skullcandy. These are super nice, clean headphones in terms of their styling as I think most of the Sol Republic headphones are. They sport a headband that they claim is unbreakable and I'm sure as hell not going to try to dispute them on that; these are MEGA durable cans. You can skate with these on and not even have to worry. I wiped out on my longboard flying down the street with these on and they flew off skidding down the road for a good solid way. Aside from some minor cosmetic damage they didn't even seem to notice. 
 
As for more details on the sound, well they sound like Sol Republic Tracks cans still, but with a much more neautral sound overall. The bass has been dialed back, but they still sound punchy. The highs sound less sharp and more smooth, and the mids are less recessed. They are a very fun and lively set of headphones, but with one major caveat: the soundstage sucks. This is something all of the Tracks series struggles with, and despite being a huge fan of them, I must admit this simple fact. The sound you get out of these will still reflect basic stereo choices in the production of the music, but they won't do the soundstage subtleties very well. All in all, they sound good, but not THAT good, and certainly not "audiophile" good. 
 
In conclusion: I like the Tracks Ultra. It's a fun headphone with a good sound and it's a logical progression to the tracks series, but it's not the most compelling one. The reason the Tracks HD is such a great headphone is how cheap you can get it, and these aren't as good of a value as the HDs pure and simple. Sol has corrected this misstep in their line with the much more compelling Tracks Air since the Ultra's release, but this is a review of the Ultra, and the Ultra just doesn't stand up in terms of value to the rest of the line. It's a good pair, but far from the best.

The Grado SR-80 has been on pretty much every list of best value in headphones ever made (or at least any that know what they're talking about) and they're there for a good screwing reason. These are probably some of the best audiophile headphones priced under $150 dollars ever made. They have a great sound all the way from their warm, fun bass to their nice and detailed mids, to their fairly open and airy sounding highs. This last bit is enabled by their open-backed design, which does allow some sound to leak, but you know that if you're buying open back headphones. There's really not much to say. These headphones look great, sound great, feel great, and have an insanely great price. If you're looking for a pair of headphones that show off why Grado has become a household name among many headphone enthusiasts then look no further than the AMERICAN company's timeless classic: the SR-80. 

Wow, where to even start with the insane, surprising, and amazing looking package that is the Beats Mixr? Well I'll start by saying this: these are headphones exclusively for DJs and people who are going to be listening to music that has been created using electronic rhythms or beats (house music, trap, dubstep). That's IT. If you try to listen to The Beatles or Arcade Fire on these your ears will puke. They're just not for that. These are headphones made for the sole purpose of listening to and DJing electronic music. However, if that's what you're in the market for then whoa boy Dr. Dre and crew have cooked up a delicious treat that you can't help but fall in love with. 
 
I am a DJ. I've been a DJ for many years now and so between mixing tracks in my studio and DJing live, headphones have become very important to me. The Beats Mixr are some of the best DJ cans ever made. Yup, you heard me. Despite being made by the same company responsible for the sonic atrocities that are the Solo HD, and the 250 dollars over price Beats Pro (fun fact: in my opinion the Mixrs actually sound significantly better than the Pro, even for the most "hood" of all trap and rap music) these cans are a really high quality product. Everything from the travel ready hardcase and fold-up design, to the coiled cord and 1/4 inch adapter that comes stuck on them are design to make life as a DJ the best it can possibly be. Plugged in to the super high-performance sound card of the well loved Traktor S4, they sound detailed enough to pick out every little subtlety you want to hear to be immersed in your mix, while bringing the backbeat and percussion to the front, making beat-matching a breeze. The flip up cans are sort of fun and certainly make one-ear monitoring easier, something pretty much every DJ likes, as well as giving it the ability to fold up into itself for travel; a useful little feature. Oh and the design? Look up any picture of these cans (I have the green neon edition, which seems to pretty much catch the eyes of everyone in the room when I walk in) to see how insanely sporty and cool they look. These cans have also gone for a design that hinges more on metal and tough, road ready plastics that give this can a vast amount more durability than anything Dre's brand has every put out in the past, ignoring the Pro, which pretty much has build quality as it's only advantage. 
 
As far as cons go, they are certainly a bit bass heavy, but honestly these aren't trying to be audiophile headphones, they're trying to be DJ headphones and the audio curve on these is PERFECT for that sole purpose. The only major con I can come up with about this headphone is that they can hurt your ears after long sessions of use, but this is only really an issue when listening to music casually, as when DJing you really don't notice, and can overlook this easily considering how much they stay on your head no matter how into it you're getting while mixing. This is great for me, as I like to really headbang and jump around on stage a lot to get the crowd hyped. These headphones really don't have any flaw, other than being associated with one of the most controversial headphone brands in the world. They easily jump to the front of the pack when compared against Denon's options and go toe to toe with the other DJ headphone greats such as the V-Moda M-100s and the Sennheiser HD25 DJ Headphone (which beats blatantly copied many aspects of, but who can blame them as the 25 is clearly the headphone to beat when it comes to DJing). The Beats Mixr truly are legendary headphones when it comes to DJing, and I highly recommend them to all DJs if you're willing to pay a little bit more due to that ever present B. 

Ahh, the Audio Technica ATH-M50: possibly one of the most positively talked about headphones of all time, and a smash hit for Audio Technica. This headphone really hasn't stopped selling like hotcakes since it's release. Walk into any college and you're going to see almost as many kids walking around with these as Beats (ok well maybe half as many). This is because people have been recommending them to audio noobs pretty much for as long as they've been a thing, so for many people this is the begining and end of their experience with Hi-Fi audio, as many people I've recommended these to say they're good enough for pretty much everything and never buy another pair of headphones until they buy another pair. While I personally think they end up being a bit overhyped when compared to some other headphones (granted, in a higher price range) due to the harshness of the highs, and their overall synthetic, unrealistic tone to my ears. 
 
Let's go with positives first, these cans have great bass that can really give you that hard-sub feel you want from bass heavy music like rap and house. They have a fairly comfortable fit that has served me well for years, as I use these on the daily to produce everything from hip hop beats, to indie music, to witch house in my home studio that i record many artists in, as well as running from my laptop when I produce hard hitting dance mixing for my DJ sets. They have enough bass to let you hear a general idea of what people listening on headphones that deliver heavy bass are going to hear, while still remaining fairly neutral, making them perfect for anyone who intends to due studio mixing for others to hear. You could also plug these into a smaller end amp and have yourself an great entry-level audiophile setup as well for those looking to dip into the now-crowded premium headphone market. 
 
There are some downsides to the universally hailed M-50. The first I would say is how harsh the high can be at loud volumes, but I already mentioned that. The second would be that the highs and mids have somewhat "fake" sound to them. They don't quite sound real, and almost come across as being a bit metallic or synthetic. This is probably my biggest annoyance with these headphones, and it is especially noticeable on songs that use the pure highs of something like and 808 drum machine hi-hat, or a loud mixed crash from a drum set. The cord is also a bit long, and they aren't the best for portable use. Overall, however, these are incredible headphones for the cheap prices you can get them for today. I think you can snag a paid for something in the $90 range on amazon now, so if you're looking at getting a great workhorse studio monitor, or your first set of real Hi-Fi cans, these are the way to go for any budget under 200 dollars. 

This is a really fun headphone, especially for on the go use from day to day. The bass is really nice and punchy, but it isn't that annoying "Beats Solo HD" rumbling bass that gets in the way and muddies the sound. It almost has a slightly held back, but warm round-ness to it. It makes rocky music and a lot of tight indie music (see Grizzly Bear, Arcade Fire, Morning Benders) and some hip hop sound great (see Earl Sweatshirt, Nujabes, DJ Cam, Blackstar), but they don't have the thumping sub bass of something like a Beats, Sol, or even ATH-M50 can that allow you to hear the raw bass energy of music like Trap or Dubstep, both genres literally designed around that sound. You probably won't want to listen to classical music or jazz on these either to be honest. The level of bass that IS present is still to much for very highly detailed music that would be better listened to on a home audiophile setup. 
 
These are headphones that can also go straight into a cell phone and be properly powered as well, making them a very odd device. They're for portable use, and sport a solid bass emphasis, but don't feel right for dubstep, trap, or even more bass heavy and/or aggressive house music. Who are these headphones for? I'll tell you who, me. They have a perfect sound signature for listening to indie music, or more experimental electronica (Aphex Twin, Burial, etc.) on the go or at a school, which happens to be EXACTLY what I bought them for. I'm a huge indie music head, and being able to listen to the chill but uplifting jams of The Shins, or the crashy rocking energy of Tame Impala on the go is just a treat, and the fact that you get that premium look and feel that Sennheiser have done so well is an incredible bonus. I guarantee that people will compliment you on them everywhere you go. 
 
In short, they're a classy, but not quite audiophile Hi-Fi level headphone that is perfectly suited to rock, indie, and some hip hop and electronic music on the go.