Hi,
 
I bought  a pair of AKG K550 recently and today when I received them I noticed something that seemed a bit odd to me. On both the headphones and the box they came in it says 'AKG K550 MKII'. When i googled for this i couldn't find any other K550 MKII, not even on AKGs website. 
 
Does anyone have any information regarding this? I don't think they're fake due to the great build quality and amazing sound.
 
Here are some pictures:
 
http://forumbilder.se/ECSB9/img-20151023-154536.jpg
 
http://forumbilder.se/ECSBA/img-20151023-154543.jpg
 
http://forumbilder.se/ECSBA/img-20151023-154622.jpg
 
Picture of what they're supposed to look like: http://www.son-video.com/images/dynamic/Casques/articles/AKG/AKGK550/AKG-K550_P_1200.jpg

Hmmmm... maybe contact the distributor and AKG? If you like the sound, then that's good .

I bought these "mkii" last month as well in Sweden. One strange thing is that these where sold at a lower price than its predecessor at ~107 euro. Personally i thing these sound fantastic. Best headphones i have ever had! 
 
After looking around a while i finally found some information on this. Found this Japanese site that have some information:
 
http://www.itmedia.co.jp/lifestyle/articles/1512/03/news100.html
 
Apparently these are launching officially the 10th of December. Had to use Google translate so its a bit hard to understand some parts of the article. But from what i can understand is that the only change from its predecessor is the driver unit. The new one is supposed to give improved resolution.
Here is the translated text i am referring to:

 However, the driver only has been changed to the new generation, it has improved the resolution feeling in sound quality. Sound field with a sense of openness while being sealed unchanged "K550", the low-pass became perhaps claim to impression perceived resolution increases. and "although not a high-resolution correspondence, has changed to naturally modern tuning through the four years" (the company). Playback frequency band 12-20000 8000Hz in impedance is 32 ohms, the numbers sensitivity such as 94dB's exactly the same as its predecessor.

Click to expand...

 We will probably get some more information on dec 10:th.

So AKG had the K550, now they are releasing the K550 Mk. II, they also have the K551 which looks like it just has the in-line mic, and then there is the K553 Pro, which looks to be an upgrade from the K550.  Seems like they have a lot of overlap...?  I just purchased a pair of the K553 Pro and have really enjoyed them.

Hi guys,
 
It would be interesting finding out if there is a real sound difference between K550 and K550 MKii and also between MKii and 553 Pro.
 
I was reading a review on Amazon about MKii versions and that fellow said something about high clamping force? Is the clamping force better on MKii vs. original K550? The main issue with K550 was a really low clamping force, making these headphones prone to bass leakage; I was bending mine to increase the clamping force and to adjust it to my head, so if MKii resolves this issue than it may be a real upgrade indeed.
 
Thank you,
Raul.

Very interesting! Thanks for sharing TheoHem!
 
I owned the original K550 a year ago, but sold it off (for stupid reasons). I now own the K553 Pro and love it too Transmaniacon!! (I live in the U.S., and the K553 Pro is only available here.) 
 
I agree raoultrifan, I TOO would like to know how they all sound different. I wonder if this MK II is any different in sound from the K553 Pro? 
 
I wish AKG would release this headphone with the detachable cable like the K551 but with a STANDARD cable included, not the in-line remote one, which people on here say can slightly distort your sound quality. And also, I'd really prefer a shorter version too, like 4 feet or 1.22 meters. The one it comes with is fine as I just tie up the extra slack anyway, but I'd prefer not to have it at all. 

Hi again.
I completely agree with you RockStar. These headphones would be a lot more versatile if the cable would be detachable. Tried taking these on a train ride but fast realized it would be the last time largely due to the extra bulk of the long cable. 
 
I still haven't found any official information on the mkii's but i found this russian article that seem to explain the difference of mki vs mkii in more detail:
 
http://prosound.ixbt.com/news/2015/december/25/akg-k550-mk2.shtml
 
Here is the interesting (google translated) part:

 

Their main difference from its predecessor - a 50-mm radiators new generation. 

Also in these headphones have ventilation holes and uses a technology Bass Reflex, which provides improved bass response.

Click to expand...

This actually confirms my own impression that the k550 mkii doesnt have a problem with the bass response as reviews of the mki suggested. The bass is perfect in my ears and i don't consider my self being a bass fanatic.
 
I wonder why the release of the mki's have been so quiet from akg so far. I thought they might release something with CES.

Many thanks for the russian link; I read it but I see no pictures with those "ventilation holes".
 
I dismantled recently my K550 to get some dumpening stuff inside and also to make them balanced with a new cable. Will you be so kind to find those vents, please? Just trying to understand how can these headphones get improved (maybe is it about the vents from the main/front side, immediately under the leather/covers?)
 
Thank you!
 
L.E.: For installing mini-XLR plugs (one for each cup for balanced operations or only one plug for single-ended) it's not very complicated, though I prefered to drill smaller holes and get the cable thought the holes without mini-XLR plugs, because my "preferred" Neutrik/Amphenol mini-XLR plugs were out of stock.

Inside the headphones I can see 3 holes on the outer circle and 8 holes on the driver here: https://i.imgur.com/P40fQuT.jpg (taken from http://www.adsforwebsite.org/t/764773/how-to-akg-k553-pro-detachable-cable-mod-and-for-k550-and-k551-lot-of-images/15).
 
 
I believe those 3 vent holes from the "outer circle" are having correspondent on some the same 3 holes from the front: http://www.innerfidelity.com/content/wonderfully-competent-akg-k550-sealed-headphone-page-2#Om5Wrq8A5Jm6utVU.97. Perhaps these are those holes ixbt.com is speaking about; if so, then all existing K550 could be easily moded by rubbing off that white band and uncovering 1, 2 or all 3 vent holes, depending on the bass quantity needed (like punching Grado drivers and creating small holes, in case you know what I'm speaking about).
 
Anyway, perhaps Tyll, Frans (solderdude) or somebody else will make some tests for the new K550 MKii, because I wonder if making those vent holes will not somehow increase bass THD.

max, 
 
I agree that the long cable is bulky, but I just tie up the extra bulk, and leave it off to my side while on the train. Usually I am able to sit alone so it's not big deal, but even if someone sat next to me, I can always move it to the other side. I wouldn't let that stop you from enjoying it on a train. But up to you. Hopefully AKG wises up and releases the K554 sometime soon with those changes made (and ones below in this post lol). 
 
Well if that is true, then it sounds like the K550 MKII is sort of an "in-between" of the MKI and the K553, b/c the K553 also has that same improvement in bass (though not sure if it has the ventilation holes??), but it ALSO is said to have a more controlled treble that doesn't run off like the K550 MKI has been found to have under certain circumstances. More on that here. They say the bass is more clearer & cleaner now than on the K550 MKI, to be specific. 
 
So it's still an improvement, but I think the K553 is still the best option. The only very minor issue I have with the K553 (besides what I said already about the cable lol) is that the cushioning on the underside of the headband is slightly LESS plush than the K550's headband. Why AKG would do that is beyond me. Although one review I saw complained about this causing discomfort, I find the cushioning is STILL JUST ENOUGH to do the job. Still, I'd rather they'd just left it alone. (And I still would've preferred having the nicer box, but that's at the bottom of my list of issues. lol)
 
Yeah I dunno either why it's been kept quiet. Seem like a lot of overlap.......the K550 MKI, the K551, the K550 MKII, and now the K553 Pro. But it really says something when the "worst" one of the 4 wins ratings & awards like these, and the K553 I own is even better?! AKG forever!! lol Even the "Against" or "Cons" side of that review have a compliment......."Sound much better than they look". So, you're saying they sound amazing?! lol (And I don't agree at all about the size. Yeah they're not TINY but they aren't pretty big either. Just a little big at most.) 

@raoultrifan
I took a closer look at my mkii´s (and removed the ear pads. I can tell you that there is nothing on the outside of the phones that looks like venting holes. Everything seems to be like the mki´s. The white band like the one in picture number two looks exactly the same.
 
I didnt try to open these because i use them at work and because there is a scary sticker on one of the screws. Looks like i would have to void the warranty if i open it. Hopefully a more gutsy person can do that
 
@RockStar2005 
I think the cable just makes a mess everywhere. When you have it in the train, when it is in the bag. 
 
Yeah they sound amazing to me, But my previous experience is a modded sennheiser hd555, the mkii´s sound much richer compared to them. 

max, 
 
I agree, it does. Hopefully AKG does something about it. 
 
Wow. It's always amazing to me when a closed-back headphone like the K550 MKII can OUTDO an OPEN-back pair of headphones like those made by Sennheiser. 
 
Speaking of Sennheiser, can you recommend any solid CLOSED-back headphones that Sennheiser makes that can measure up to the K550 MKI or MKII, and are between $100-$200? I can't seem to find any. It's not really for me, just for people I know. And by "solid" I mean ones that have great sound quality, soundstage, and are NEUTRAL. So many headphones in this price range seem to always be bass-enhanced in some way, or not have great soundstage. 
 
I myself had the HD 598 a little over a year ago. They were my first premium headphones, and as great as they sounded and looked, the reason why I returned them was comfort, or lack of. lol They clamped just tightly enough on my sides for it to be an issue, so they had to go back. But in retrospect, that was most likely the right choice anyway b/c they were open-back, which of course meant that I would not be able to put the volume up around other people like on the train (etc), and that would've made me regret buying them. 
 
P.S. I bought this case off Amazon for my K553, even though it was actually made for the K550 (about the same size, so doesn't matter anyway). So if you're looking for a sweet case to keep it in for travel or home storage, I highly recommend it! 

maxonline said:

  @raoultrifan
I took a closer look at my mkii´s (and removed the ear pads. I can tell you that there is nothing on the outside of the phones that looks like venting holes. Everything seems to be like the mki´s. The white band like the one in picture number two looks exactly the same.
 
I didnt try to open these because i use them at work and because there is a scary sticker on one of the screws. Looks like i would have to void the warranty if i open it. Hopefully a more gutsy person can do that

Click to expand...

 
Thanks Max!

Just wanted to add my 2c here.
 
I'm looking for something to outdo my SRH440 in terms of midrange and treble and would not ruin me financially. I was in a listening room yesterday with my old cans, the new K550 mk2, K550 old ones, Shures SRH840 and Brainwavz HM5.
 
Long story short - the K550 old version and Shure SRH840 were very good in terms of clarity, balance, detail, even bass definition without it overtaking the whole sound presentation. The Brainwavz were a bit worse due to some strange thing it did to vocals, and I would rate the new K550 mkII as the worst of the lot. You could here that the mids and treble are of high quality, but the upper bass does not let you experience that. There is too much of it. I was surprised how different the K550 mkII souded if compared to the old version. The new ones would surely be better for someone listening to pop and electronics, but any music with some live instruments and not overprocessed vocals just sounds bad.
 
That is my personal opinion. I wonder how far off my conclusions are if compared to what you experienced when listening.

jakkul, 
 
Since you mentioned that you really liked the original K550's sound, then I must recommend you look into my current AKG K553 Pro headphones. They are an improved upon version of the K550, but look almost exactly the same! There is a TINY bit less padding underneath the headband, but I still find them to be pretty comfortable. More about their improved upon features here, but a quick summary would be that the bass is said to be clearer and the treble is more controlled now. (I had the original K550, and they were the FIRST headphones I ever really loved, and were my third pair.) 
 
I've had the K553 for months now, and I can say they are the BEST headphones I've ever owned, and I've owned (and returned or sold off) several, including the original K550 itself. Other headphones I've had are the Audio Technica ATH-M50X ($160) (my least favorite of all of these, though super comfortable), the Sony MDR-1A ($299), Bowers & Wilkins P7 ($399), Oppo PM-3 ($399), and the new Blue Lola ($250). (My first ever was the Sennheiser HD 598 (($146 now, though I paid $208 at the time)), but since they're open-back, I don't count them here. They were a bit tight on my sides, which is why I returned them, though other people I knew found them comfortable.) The K553 IMO outdoes them all, because of the HUGE soundstage, but also b/c of the extra clarity and neutrality of these headphones. The bass isn't strong, but it's there and you can feel it. The mids and treble are VERY clear and not subdued or confined-sounding in any way. Listening to music on them is MAGICAL! They look very premium (little to no plastic), are a good size, have folding earcups, and are quite comfortable too. More about them can be found in 2 different comparison reviews I wrote which can be found here and here. They are closed-back of course, just like the K550. 
 
One thing is, even though you don't HAVE to have a good amp/DAC (amp is not enough IMO) or DAP to get the best out of any headphones, including these, I still STRONGLY recommend you get one if you don't already have one (hopefully you do). I can recommend 2 for you now that cost less than $130 (my current amp/DAC is the Oppo HA-2): 
 
1) The Cozoy Astrapi: I don't own it, but I'd tried it out before giving it to a friend of mine for his b'day last Fall. When I tried it out, it sounded very good and even a guy at the T-Mobile Store I was trying them out at thought they were fantastic and even took pics of the box so he could buy one himself. lol It's tiny..... like a flash drive, made of metal, doesn't have a battery so no recharging necessary (uses about 5% of your smartphone battery an hour), very easy to use, and nicely priced too. Best price is found by buying it from a reputable seller on eBay (free shipping). It's compatible with all phone types and PC.
 
2) The FiiO E18K Kunlun: Here you have a great amp/DAC which also offers Low/High Gain options, Bass Boost (I don't recommend it though), and more power than the Astrapi can offer. It has its own battery, so you must recharge it separately. It also doubles as a power bank, so you can use it to recharge your phone. Very nice quality, like the Astrapi. Reputable sellers on eBay (free shipping) (anyone who's sold over 100 items, or especially over 1000) are also selling it too. This is very similar to my Oppo HA-2 in features and design. 
 
The K553 is a "U.S. only" edition of the K55X series. If you don't live in the U.S., you can still buy them off sites that sell to other countries. (What country are you in?) For best price, I would check here (Adorama) or else eBay. eBay will sell internationally, though I would buy from the first link (Adorama) since they will for sure have a return policy, where sellers on eBay sometimes do not, though usually do. I don't see any eBay sellers pricing it below Adorama's price, so again, I'd recommend buying it from them. You can check to see if Adorama delivers to your country or not here. (Scroll down to "What countries does Adorama ship to?". If buying off eBay, always read full seller description first.) 
 
P.S. I bought this case off Amazon for my K553. Awesome hard case!! You could buy it down the line if you want. 
 
Hope that helps!