The Audio Technica ATH-M30x are excellent sounding headphones in the sub $100 range. I'm using the M30x as a second pair of headphones to listen to music and when watching movies or TV shows on an iPhone, iPad, or through an AV receiver. I wanted headphones that would sound great, be well built, be portable, and yet be affordably priced. In those regards, the M30x delivers.

The M30x is a nicely designed successor to the popular M30 headphones which they are replacing. I really like Audio Technica's styling update for the M30x, giving it a look similar to the iconic M50 and newer M50x headphones. Like the M50 and M50x, the M30x now features a collapsible design for space saving portability. Both of those are welcome changes from the dated looking and clunkier M30. A few months back I purchased a pair of M30 headphones, used them for a couple of weeks before returning them, and then purchased the M50 headphones. The design and feel of the M30x is much improved from the M30.

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SPEC COMPARISON BETWEEN ATH-M30x & ATH-M50x:
The M50 and M30 were the most popular headphones in Audio Technica's Professional Studio Monitor Headphone lineup so my guess is that the M50x and M30x will be also so I've written a spec comparison between models.

1. The M30x has a 40mm driver compared to a 45mm driver in the M50x.
2. The M30x has a frequency response of 15-22,000Hz compared to 15-28,000Hz with the M50x.
3. The M30x has a maximum input power of 1300mW at 1kHz compared to 1600mW at 1kHz with the M50x.
4. The M30x has a sensitivity of 96dB compared to 99dB with the M50x.
5. The M30x has an impedance of 47 ohms compared to 38 ohms with the M50x.
6. The M30x weighs 7.8oz compared to 10oz with the M50x.
7. The M30x has a built in cable compared to detachable cables with the M50x. The straight cables are both 9.8'.

With a higher sensitivity, lower impedance, and higher maximum input power the M50x are a little easier to drive, are a little louder, and can handle more power before clipping than the M30x.

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COMPARING AUDIO TECHNICA's PROFESSIONAL STUDIO MONITOR HEADPHONE LINEUP:
If looking at other models in Audio Technica's lineup, the M20x, M30x, and M40x all have 40mm drivers whereas the M50x has 45mm drivers. All have a frequency response on the low end of 15Hz but as the headphone models get better so do the higher end of the frequency response, 20,000Hz with the M20x up to 28,000Hz with the M50x. The M40x and M50x feature detachable cables whereas the cable in the M20x and M30x is built in to the headphones. The M20x isn't collapsible while all the other models are. When examining sensitivity, impedance, and maximum input power, as the models get better the headphones tend to increase in dB's, become easier to drive with a lower impedance, and are able to handle more power before clipping.

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SOUND QUALITY OF M30x & COMPARISON TO M50:
The M30x offers excellent sound quality for its price. The headphones produce a rich, clean, and detailed sound with a good amount of bass. I'm really impressed with the sound they are able to produce.

Having the M50, I was able to do a comparison between the two headphones. Since many reviewers who own both the M50 and M50x headphones state that the two models sound identical, my sound comparison between the M50 and M30x should provide a good comparison in sound between the M30x and newer M50x headphones.

The M50 headphones are a little louder. They produce better bass as a result of the 45mm drivers compared the 40mm drivers in the M30x. The sound from the M50's is also fuller and has better separation. You do get what you pay for but when considering sound to price the M30x offers great bang for your buck.

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PROS:
1. Produce a rich, clean, and detailed sound with good bass.
2. Affordably priced, great bang for your buck.
3. Comfortable to wear.
4. Attractive design and lightweight.
5. Collapsible for space saving portability. When collapsed they are noticeably smaller than my M50's collapsed.
6. Comes with protective carrying pouch and 1/4" adapter for headphone plug. The 3.5mm plug allows the M30x to plug into smartphones, tablets, laptops, and desktop computers. The 1/4" adapter allows the headphones to plug into receivers, mixers, and other audio equipment.

CONS:
1. The "L" & "R" indicators for the cans are inside the headband area and are hard to see in dim lit areas. I much prefer their placement on the can swivel mechanism with the M50/M50x. I know its minor especially if you just remember that the cable comes out of the left side but I thought I'd mention it.

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SUMMARY:
The ATH-M30x headphones continue Audio Technica's legacy of producing amazing headphones. At the price point of the M30x, they are very hard to beat. If you are looking for a pair of headphones that sound great, are well built, are portable, and yet are affordably priced as I was, I highly recommend the M30x. If considering other Audio Technica models I recommend spending a little extra money and purchasing the M30x over the M20x. The collapsible design is very nice and the M30x allows almost double the maximum input power than the M20x. If sound quality is your concern over price, the M50x is superior with better bass, separation, and a fuller sound. The build quality is also nicer with the M50x. My M50's feel sturdier, the headband extender feels more durable, and I like the swivel feature of the M50 cans. That's not to take away from the M30x because they are well built headphones for the price.

I have been in radio and TV broadcasting over 40 years. I currently do a regional radio morning show on WBYZ-FM in southeast Georgia, USA. Headphones are a VERY important tool in the work I do. I have owned a lot of pairs from different manufacturers. I did a little more research this time before I bought anything. There are so many brands, styles and specs in the market now. Our station control room monitors a signal right from a digital FM receiver. I just finished my first four hour show with my new headphones. At my age and with my experience, it may seem silly, but...I was excited and surprised at the sound between my ears when I opened the mic for the first time this morning. Great sound and a comfortable fit! For the price, I don't believe I could have done any better.

After giving these pair of headphones about a month of casual listening and breaking in, I can say that I'm quite satisfied with my purchase. I am not audiophile and just you average casual listener of music, however I have done a decent amount of research before purchasing these pair of head that fit into my budget range.

Comfort:
Firstly I will state that I am a slightly above average size person standing at about 6 feet tall and 185-ish pound, with a head to match such body. This will provide you readers a frame of reference when I talk about my experience with the comfort with these headphones.
Overall the comfort is ok-decent for me.
Goods
-The ear cups are fairly large and elongated such that my ears can fit into nicely
-The padding on the top is also subtle and nice such that it does not bother while you where them.
-Clamping force is comfortable and will get better as you wear them overtime.
Bads:
-After about 30 minutes to an hour of wearing these you do start to feel some heat build up around your ears and sometimes the top of your head around the headband. I can usually last 3 hours before I need to take them off.
-Bringing these headphones down and around your neck does feel tight and almost choking-like, flipping the cups outwards helps a bit.

Build Quality:
Overall I feel that for what you are paying for you get a very solid piece of audio equipment.
Goods
-The headband is very flexible and resilient
-The pleather padding are quite nice and soft and have not experience and flaking or damage so far
-The flat adjustment bars are nice solid metal, not sure if steel or aluminum but are nice either way.
-Cable is nice and thick and has a nice flexible rubber outside which will help prevent breakage.
Semi-Bads
-The cup themselves do have the sort of hollow plastic feel, however this is obviously a small nitpick of mines
-THE VERY LONG CABLE that several other people have complained about, HOWEVER I have found a neat trick on the web on how the reduce the length and actually make it look quite stylish. You essentially briad the cable the same way you braid hair in the 3-way braid style.

Sound Quality:
Now for the most important and obviously most subjective part of the review, and that is the sound quality.
I personally quite like the sound that these pair of headphone create, though I would like some minor tweaks done to them personally.
Trebles/Highs (High Pitch range of sounds): For the most part it is nice and clear and note can easily be discern, however I do feel like it slightly lacks a bit in emphasis.
Mids: Audio Technica advertise these has great mid range studio monitors headphones and that is exactly what they are, the mids are the best part of these headphones. Male vocalist and other instrument often shine and and are great to listen to.
Bass/Lows: Relatively tight bass, the amount of bass present here is enough to satisfy me as it i quite punchy and pretty decent amount of emphasis. However hardcore bassheads might not find these satisfying and I would recommend other headphones such as the Audio Technica Solid Bass line or something. A more fuller sounding bass would be nice, but that would defeat the purpose of accurate studio monitoring that these headphones are meant for.

Sound Leakage/Noise cancelling:
When I'm our in public or in a room with other people, it doesn't seem that I'm bothering people even when I have my volume up to round 90%. So I would assume that the passive seal around your ears is sufficient.
As for noise cancellation, it does a decent job, however strong winds, loud motors, and other loud ambient noise might not be fully blocked out.

Appearance:
The least important, but still important aspect is the way these look.
Obviously you can judge from the picture but I personally think they look nice, sleek, and modernized from the old variants.
The Audio Technica Logo really set it off on each side of the ear cups.

PS there are 47 ohm headphone and I am able to power these with my iPhone 5 with no problem. I usually listen to around 75-90% volume depending on the genre and song. However for people who like to crank their music and you might want to consider a portable amp.

Overall I give these a 4/5 as they are a great solid performer with a nice price.

These are not the M50's but for the price they make a really good day to day headphone that you can take with you on the go without fear of damaging them etc. These can easily be connected to a mobile device like an iphone and deliver a good listening experience that is truly enjoyable for the price. Sound appreciation is subjective, these offer a similar signature to their brothers, the M40's but at a lower price.
The cans fit around my ears quite well and the fact that these are not round really helps with comfort.
I am thinking of changing the ear pads as they do get hot after long periods of time but other than that I have no other complaints.

Do your research and know your needs. If you can try in person the multiple headphones you are considering, it really can help you make an educated selection. Also go to the forums and lurk/ask around.