I've purchased my MC5's from Ebay around a year ago (If I remember correctly.)
 
Since then I've kept them as a backup IEM whenever my main IEM would break on me.
 
The build quality on these are just fantastic, I've tried recabling one before but I broke one of the drivers on it because my soldering iron was too hot.
But yeah, the build quality is really good, the cable is of average thickness however it is strong.
The metal housings are quite strong aswell, the thickness of the housing is big (1mm if I remember correctly)
The plastic on the housing is decent, however on my pair a very small piece of the plastic on the corner where it connects to the metal broke off.
But it doesn't seem like an issue to me. The strain reliefs are flexible but very strong, especially where the cable connects to the earpiece.
 
Sonically I found the MC5's very neutral and boring at first but after listening for longer periods with them you'll start noticing how much detail these IEMs produce.
The bass is obviously not huge in quanitity but the quality however is good. Its quite tight, and extends well.
Mids are detailed aswell, I found vocals lifeless at first but after a while I really started to enjoy vocals, the detail just makes it alot more immersive in my opinion.
Highs sound good, its detailed but its not sparkly. It also doesn't extend very far and they can be quite sibilant with poor recordings.
Soundstage is average, its not very wide but depth is quite good. Compared to the Vsonic GR06 soundstage depth seems a bit better with the MC5's
 
Comfort is okay with these, atleast for me. I can insert them quite deep into my ears since I have deep ear canals. But poeple who have narrow ears might hate the MC5's, yes there are foam tips included with them but they feel very rough, as if they're sandpaper. But yeah, comfort hugely depends on your ears.
 
Isolation is what I love with these IEMs, I can't hear poeple talking around me. I can barely hear a TV playing at around %50 volume from 4-5 meters away. I wouldn't recommend using these while cycling or doing anything that requires you to hear the area around you. I would recommend them for poeple that travel with a bus or a train.
 
Overall, I really recommend the MC5's for poeple who are looking for an analytical and neutral IEM that isolates really well. I'm now a fan of Etymotic, especially because of the build quality. Can't wait to buy the ER-4S.
 
Update: Also, it matters how deep it is inserted. I just decided to try out short single flange tips on my MC5's and now the soundstage is a bit wider and theres also a bit more bass. Highs extend further when using short tips with a big barrel.

Sound comparison to the hf5:

Slight increase in bass (may be due to the dynamic driver moving air). Drum kicks and low bass feel more realistic on the mc5, however the bass is of higher quality on the hf5. It's a good compliment if you love Ety's sound with a bit more kick in the bass. And it responds to equalization much much better than the hf5, I could turn this into booming bass monsters with a degree of clarity being remained. Lovely.

Lastly the treble isn't as bright and rolls off earlier than the hf5, this could be a good thing or a bad thing depending on what you want. The mc5 while being a lower model above has some advantages due to its dynamic driver, but in terms of speed, detail retrieval and clarity, the hf5 murders it.

I ended up returning it, I have a much better DD IEM: EX600. The mc5 is no slouch though, it's just that I won't use it, I'd rather use the EX600 for DD and the hf5 for BA.

I’ve had the Etymotic MC5 for over a year and a half and thoroughly enjoy them. They have excellent noise isolation; especially when using the foam tips. The sound comes out very crystal clear without distortion. The cable has held up to much wear and tear throughout my time owning this iem. My main complaints are that the jack is not right angled; but rather J shaped making it easier to damage the headphone jack. Also, if you wear it for very long periods of time with the tri-flange tips you will feel some irritation. Said irritation is non existent in the foam tips. When I purchased my MC5, there wasn’t an option for in-line controls. Nowadays they do give you the option of in-line controls or not.
I’m really impressed with the accessories that come with the MC5. You get 3 sizes of tri flange tips, basic tips and one pair of foam tips. Also, you get a filter kit to clean out your IEM, ie a tiny filter and a small steel rod to retrieve and insert said filters. You also get a shirt clip; however I myself don’t care for shirt clips as they’re more of a burden than a help in my personal experience.
If you’ve never bought a pair of Etymotic in ear headphones before, this would be a great introduction to the brand; especially if you want absolute noise isolation. As soon as you put the MC5 in your ears fully; you will not hear any outside noises even when no audio is being played. When wearing these, be very aware of your surroundings as you will be deaf to the world when these headphones are properly inserted in your ears; especially when using the foam tips. The foam tips seemed to have even more noise isolation than the tri-flange tips.

N/A

(Bear with me, this is my very first review...)
 
Included in package:
Triple Flange tips, small
Triple Flange tips, normal/medium
Glider tips
Black Foam tips
Replacement Filters (+ Filter replacement tool)
Zippered Carrying Case
Snap-on Cable Clip
Etymotic MC5 earphones
 
 
Comfort: 3/10
I found these iems fairly uncomfortable; my ears ached moderately after long listening sessions. All tips included never really provided much comfort. The "normal" Ety Triple Flanges plunged deep into my ears and stretched them out. The "small" Ety Triple Flanges were too small and I could not get a sufficient seal with them. The black/grey foam tips were just terrible, they sounded significantly worse than the triple flanges and felt like they were shredding my ears to pieces. Maybe I got a bad pair? The Glider tips were the most comfortable by far, but the sacrifice of SQ for comfort was too large, so they went away.
 
The casings are pretty bulky as well, I'm sure that contributed to some of my discomfort.
 
 
 
 
 
Sound Quality: 7/10
Coming from cheap bassy iems when I purchased these, I was very disappointed in these at first listen. But within a few days, I began to understand how to appreciate the Etymotic house sound. Sure enough, I rediscovered my whole collection.
 
NOTE: *These iems WILL reveal bad sources. But not as severely as some make it out to be.
 
After discovering head fi and getting these, I began to update my media library to FLAC. At first, I could not hear any difference at all. But during very long listening sessions, I began to hear faults in my 192 kbps mp3 files. After burning the same music to FLAC, I noticed a definite difference. Thank Etymotic for training my ear and turning me into a neutralhead or...?
 
As I gained more experience (haha) I began to realize the Ety's faults and strengths.
 
As others have said, they are dry and clinical at times. With some songs this can be very boring and not enjoyable. While doing something else, such as browsing the internet, these can really fade into the background and before you know it, completely disappear.
 
During most loud rock songs, the Etys can sound congested and boxed in to the point of annoyance. The soundstage certainly is below average.
 
The detailed treble of these really did amaze me. I enjoyed all the details and nuances in my rock. Yeah, call me crazy for liking rock on the Etys. But, as mentioned before, on most of my heavier rock, the soundstage is less than adequate.
 
I do have a few gripes about the mids. They are dry and congested, but, in a contradiction, I think electric guitars really rock on these iems.
 
To my ears, the lows seem to just blend in to the background, not overly present or offensive. Just "there". But when they do show themselves, they rock. Their quality really does allow me to discern different bass notes. Although I tend not to pay much attention to them, because hearing bass (keyword: hearing) isn't very appealing to me vs feeling it.
 
________________________ _ _ _
 
Overall, would I buy these again? Maybe. For a throw around pair or for a gift, but never again for serious listening.
 
*Please take my opinions with a small grain of salt, as this is my very first review, and hearing is subjective.
 

Etymotic Mc5 vs. Etymotic Hf5​

 
[size=11pt]Both are are very ‘true to the ear’ as Etymotic would say... both have amazing tri-flange eartips for superb noise isolation, best in the business actually... and both led me to feel that clarity was an essential part of my music, perhaps even more so than dynamic bass and shiny treble... but in the end, well, lets just save it for the end, shall we?[/size]

[size=11pt]Mc5[/size]

[size=11pt]Fullness of vocals, more bass quantity, slightly recessed.[/size]
[size=11pt]Better construction of the housing[/size]
[size=11pt]Memory free cable is just that... Memory free[/size]
[size=11pt]More difficult to fit.[/size]

[size=11pt]Hf5[/size]

[size=11pt]Great bass extension.[/size]
[size=11pt]Bright treble, a pleasant shimmer on cymbal crashes[/size]
[size=11pt]Articulation of stringed instruments[/size]
[size=11pt]Smaller housing is comfortable in the ear[/size]

[size=11pt]Music:[/size]

[size=11pt]Owl City - Fireflies - BBE ViVA[/size]

[size=11pt]Listening to this song, the first thing I notices about the Hf5 was the tinkling intro, sparkly, and close, as the song progresses the verse is laid out nicely, even tonality, and not much peaknesss throughout... then comes the chorus, a clashing crescendo of noise as more instruments are suddenly added to the mix, not gracefully, but with a sudden crash that is overpowering for a moment. Not so with the Mc5. It has a tighter, more controlled transition from verse to chorus in this particular song, it can handle the ‘dynamics’ better... pun intended.[/size]

[size=11pt]Elton John - Can You Feel The Love Tonight - BBE ViVA 2[/size]

[size=11pt]Stunning rendition piano in this track was heard on both earphones, though slight differences began to be apparent in the bass department. The low thrum heard in the background of this song extends progressively deeper with each note i the beginning of this song... and this is where the Hf5 came through the best, in its extension of the bass notes, which where satisfying on the Mc5, though not as deep as I heard them on the Hf5.[/size]

[size=11pt]Beight - Invisible City - BBE ViVA[/size]

[size=11pt]I listened to this song purely for is simplicity, and the use of warm vocal tones throughout. The presentation of the vocals, was, however, different regarding each phone. The Hf5 for example is stunningly accurate, more technically detailed, and clear, presenting the human voice as you would hear it from another person in an open area, with no reverberation, and no echo. While it was pleasant to hear something sound so precise with so natural an instrument, it wasn’t as ‘real’ as it could have been. It did not sound electronic, nor coloured, or fake in any way, but it was not a real as the Mc5. The Mc5 that made me anticipate the feeling of breath on my cheek, so close, I could touch it.[/size]

[size=11pt]Overall, I think the Hf5 wins in the sound department, but by a minuscule amount because it’s not readily apparent that it sounds nicer in general, but after a while, I could see myself justifying spending $20 more... But not $40, and definitely not if it is going to break a few hours later from changing the eartips.[/size]

[size=11pt]I the end, the dynamic won, by a small, but logical amount in the overall value department, helped by its durability and superior cabling job. Happy Hearing![/size]

Audio Quality: 1/10
 
These sound much worse than my cheap Sennheiser cx300s. They manage to suck all life and energy out of any track I listen to. I actually enjoy an analytical and neutral sound signature. These however don't have the detail or sparkle to make up for it's lame frequency response. They just sound thin, small, and dull. There is no fun to be had in the low end. It's there, but it will not make you bob your head or shake your tail feather. With super cheap IEMs, you at least usually get some silly fun bass for amusement. Sadly, these IEMs will just make you enjoy your music less.
 
The mids are the focus of these IEMs, and unfortunately, they also suck. Congested, boring, edgeless.
 
The highs are a joke. I thought the Ety sound was all about the treble?
These headphones have magical treble: they can make entire instruments, disappear! Where once there was a high hat, there no longer is! TA DAH! My Senn cx300s sound like $300 IEMs in comparison.
 
I don't really even understand how this happened. Its as if all frequencies are recessed, but turning up the volume solves nothing.
 
And obviously there is no sound stage, its an IEM you dummy.
 
Comfort: 6/10
 
I'm being nice, since I actually found these to be very hard to fit with the stock tips. But this is partially because my ears are jerks and are shaped stupid. I fixed this with some after market foam tips.
 
Isolation: 8/10
 
Great isolation, I can't hear crap!
To bad I'd rather listen to the outside environment than these pieces of crap.
 
Design: 9/10
 
Built extremely well. The cord is kevlar reinforced, which will come in handy when you try to hang yourself after listening to these crap IEMs.
 
Value: Whatever, don't buy these. Save your money, they suck. Others won't come out and say it as bluntly, but this is clearly the case.
 
I wish I'd bought 2 pairs of cx300s instead of these.