Monster Turbine In-Ear Headphones

I got these things on Amazon nearly 6 years ago, and still use them on a daily basis - as such, I am insanely happy with the durability of these things. 
 
They clearly have a big bass preference, as you can see on the frequency response chart, but what's most notable about the bass is the range, extending crazy far down. The bass is not particularly tight, nor particularly fast, but has a good kick to it, and can be slightly boomy. The term that comes to mind is "springy" bass. The mids and highs are actually fairly impressive for an IEM with such a strong bass focus. Mids are a little bit muted, but not terribly so. As others have said, the bass can muddy up the mids a little bit, but it isn't much. The highs to me are somewhere on the more fun side, with a little bit of sparkle, but no trace of sibilance. The sound signature is perfect for electronic dance music as well as hip hop. They're also good with rock, albeit with a bit of EQ tweak to lower the bass a bit. 
 
Apart from the sound quality itself, these things also have FANTASTIC isolation. On the downsides, they are very heavy, making fitting a little bit tricky, and the included tips aren't great, but they do at least come with a lot of tip options, which helps. 

To be perfectly honest, when I first heard of the Turbines, I thought that they were just another Monster consumer product like Beats. That is, heavy, muddy, bloated bass, recessed mids and highs. When I first heard them, I was pleasantly surprised and I don't own these. To start with, it will be worth knowing that these are extremely sensitive to insertion depth and when it isn't perfect, the sound can be odd, so make sure that they fit properly before you judge them. I borrowed them off a friend so I don't know what it comes with etc and I will just get straight to the sound. Also, these have already been used for a few years so should be fully burnt in if you are one of those who care about burn in. 
 
Sound
If you have read any of my other reviews, you will know that I split the sound section into 3 main parts - bass, midrange and treble, so here we go!
 
Bass
The bass is certainly north of neutral, there is no doubt about that, but it is actually really pleasant and it excellent for mainstream music which are mostly bass heavy. The bass really does lack detail though and that becomes very apparent when you hear other IEMs like the Brainwavz B2s which have little bass, but very good detail. The bass however, it not as fast as I like, but boomy bass may be your type of sound and in that case, this will be an excellent choice. Also, the bass does bleed into the mids and sometimes drown them out a little, but it is quite bearable. A lot of people, including me, would call the bass a bit bloated, but it is supposed to, and Monster has done a great job at making an IEM with just the right amount of bass for basshead audiophiles while still satisfying average consumers. 
Midrange
I was expecting the midrange to be recessed like the Beats tours, but they really did remind me of the Monster Jamz which have quite a nice midrange but sounded much more natural and a bit less recessed. The vocals sound quite meaty and impressive for an IEM of it's price, but again, female vocals still sound a bit metallic and lifeless. Instruments are quite nice, but lack a bit of realism  and sounded darker than what they should sound like. As mentioned above, the bass bleeds into the mids, but it is still quite nice and I doubt that it would really affect you if you haven't heard Vocal separation is OK, but nowhere up to the level of the slightly more expensive Rockit Sounds R50. The detail level is good, but not great because of the strong bass. I actually really liked the midrange and prefer it to many more expensive IEMs I've heard. 
Treble
I am actually most impressed by the treble. I was expecting a veiled mess for the treble, but it wasn't like that at all and improves greatly on the Monster Jamz's treble. The cymbals are not just a click, but actually have a very nice decay which, while on the short side, is still enjoyable. I has some sparkle, but doesn't go over the top like the B2s and is very smooth and non fatiguing. People who are used to a bright IEM will find these very dull and veiled, but these are actually just about neutral, but may be just that few DB off. There is no odd peak which plagues many IEMs that I have tried. Also, there is absolutely no sibilance even after I pushed it well past safe listening levels which is another plus for the treble. It really isn't like any of the other Monster IEMS. 
Instrument Separation
This is where the Monster turbines do not do well at all. It sounds very coherent, but it is quite hard to tell each instrument from another on congested tracks. The B2s really do do way better than these in that aspect.
Soundstage
The soundstage was rather impressive for a $100 IEM. It was wide and quite deep, but not very tall. 
 
Conclusion
If you are looking for a very nice bass heavy and fun IEM under $100, these are an excellent choice, but maybe you will want to check out the Shure SE215s as well. I did really enjoy the turbines and please don't just think that they will be terrible sounding because they are from Monster like I did. Give them a run and you might be impressed. 

After a six year love affair with a pair of Shure e4cs, they bit the dust & my wallet didn't allow for a similar investment. On my trip to J&R the day before an international flight, they were sold out of the Sure 215's I planned to try out. So I picked up the Turbines.
First out of the box I was greeted with several inner boxes, on my subway ride home a gratuitous pile of cardboard & plastics formed around my feet. What's that you say Turbines? "Life is too short for bad headphones." Did your CEO write that copy? What's with audio gear & embarrassing copy? Oh look, two carry cases, both disgusting.
So let me get this out of the way, within four months they were broke. Apparently this doesn't seem to be the norm so I'll try to hold my hatred at bay.

1. Bass good. When listening to tracks & genres with great bass these headphones became quite "fun".
2. Symmetrical buds means you must annoyingly use brain power & eyes to know which ear is left & right.
3. Broken

I replaced with Shure SE215. Similar price, I like them better, although the Turbine's have superior bass & comfort. But no "love" for either model.