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Phenomenal sound. Makes other good IEMs sound low-fi. My reference IEM.

A Review On: AKG K3003

AKG K3003

Rated # 38 in Universal Fit
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Pros: Expansive soundstage, extremely articulate and detailed, musical, lightweight and non-obstrusive

Cons: Cables not detacheable, bass may be lacking for some

I must admit, the AKG K3003 was not something that I ever wanted to purchase when they first came out.  At $1,600 CAD ($1,200 USD), they were probably the most expensive IEMs available at the time. 


In a world where you could buy custom IEMs for less money and have more drivers, I (like many others) dismissed these initially.  A pair of JH Audio JH13 was much more appealing to me at the time, although I had never bought one (more on that later).


Enter 2015, when the price of the K3003 could be found for about half of MSRP.  The K3003 thread here on Head-fi, combined with the more accessible MSRP had really gotten my attention, and so I finally bought a K3003i (same IEM, but with the inline iphone mic./cable) because the original K3003 was not much discounted.


In the Box:

Once unboxed, the K3003i looks and feels expensive, dispelling some of my initial thoughts about this being a massively overpriced/marked up product.  Included are three sets of "filters" that could be swapped out to alter the characteristic of the sound.  There is one for "reference", one for "extra bass", and one for "extra treble".  An inline adapter for the iPhone-ready 3.5mm terminal to a standard terminal was included, as well as an airline headphone adapter and a high quality leather pouch. 


The box of the AKG K3003i


Contents inside the box.  (Original clear silicone tips not shown)



What is Special about this IEM, and why does it matter?

In my daily work, I am an engineer and also a fine art and portrait photographer.  However, I will refrain from presenting too many technical details that may not be relevant to most people.

The K3003i is a special because it features a hybrid driver system with one dynamic driver and two balanced armature (BA) driver per side.  In AKG's own words, the dynamic driver is used for distortion free lows (bass), while the two BA drivers are used primarily for accurate mids and for sparkling highs.  Most conventional IEMs feature dynamic drivers, whereas offerings from Shure, Noble Audio, and most custom IEMs feature BA drivers.  


Literature with cutaway diagram showing placement of the dynamic driver and 2x BA drivers


Coincidentally, I have experienced both types of IEMs and the strengths of each.  


Dynamic driver IEMs are probably less expensive to make.  Typically, dynamic driver IEMs have a nice, coherent sound with the ability to produce sufficient bass, but may be lacking in articulation and detail.  In my opinnion, they are well-suited for vocals and drums, but not so much for instrumentals where you want to hear everything sparkle in the background.  

Some dynamic driver IEMs I have are: Sony EX1000, JVC FX850, and just about every other inexpensive IEM out there I have listened to.


BA driver IEMs, on the other hand, are a much newer technology.  BA drivers are alot smaller and are used in things like hearing aids.  The strengths of BA drivers is exactly the inverse of the dynamic drivers.  That is, BA drivers excel at playing back fast paced music, such as dance, instrumentals, etc., without a hint of incoherency.  The problem with BA drivers is that they often sound shrill and lacking body, similar to what your speakers would sound like if it was missing a woofer or subwoofer.  This is also part of the reason why most BA IEMs use multiple drivers in their design.

BA driver IEMs I have, or previously owned included the JH Roxanne, Fischer Audio DBA-02, Audeo PFE111, Sony XBA3, and Earsonics SM3.


Essentially, the goal of the K3003i was to create an IEM that combines the strengths of both dynamic driver and BA driver technology.  This is not a new concept necessarily.  In fact, AKG also tried a hybrid-driver setup in the 70s with the K340 Electrosat-Dynamic Headphones, which I have, and mostly enjoy.  The K340 combines electrostatic drivers with dynamic drivers for the same reason that BA drivers are paired with dynamic drivers in the K3003i. 


The K340 is very rich and full sounding, detailed, and has good bass impact.  Where the K340 falls short is its ability to handle fast-paced music, where it may sound a bit muffled or incoherent as the dynamic drivers could not keep up with the speed of the electrostat drivers.  If we use a photography example, this would be simliar to a picture of people on the street, where the speeding cars are blurry, but the pedestrians are in sharp focus. A technically perfect photograph would be one where both the cars and the people in the picture are in sharp focus for us to see, and this is the challenge that the K3003i needs to address.


AKG K340 Electrostat-Dynamic Headphone, circa 1970s


Illustration showing the hybrid driver system of the AKG K340




Fortunately, there are no incoherency issues in the sound of the K3003i.  That is, both the pedestrians and the cars in this photograph are in sharp focus all the time.  AKG has successfully solved this engineering problem.


But, how does it sound?  To be perfectly honest, my ears did not understand the sound from the K3003i in the beginning.  They sounded very, very detailed with an expansive soundstage, but somewhat anemic and lacking in bass compared to all other IEMs I have tried.  I almost returned these for something else.  However, I stuck with these for long enough to try them with different DAPs and music and finally understood what the problem was.  All IEMs I have listened to up to now were very much coloured, non-articulate, and have much more bass.  These are the important points to understand.    

Let me explain.  The K3003i has a neutral presentation and doesn't add too much to the sound.  Additionally, although these IEMs are easy to drive from any portable device, they prefer a slightly warm sounding source.  In this way, the K3003i is similar to headphones like the HD800, which do not offer much of an enjoyable listening experience when paired with most cold-sounding amps due to its overly-analytical nature.  The K3003i is far more forgiving of the source music bitrate than the HD800, and far less analytical in that regard.  


Once I swapped the included tips to a set that was more fitting with a better seal, the bass quantity and impact became just right.  It was perfect in a way that the rest of the music does not become overshadowed or overwhelmed.  This solved the bass problem.  


Next, I compared these to my other IEMs: my previous favourite Sony EX1000, the JVC FX850, and the very expensive JH Roxanne.  A comparison with other high-end IEMs is a big part of the journey to understanding and enjoying the K3003i.



All these IEMs provided more bass quantity (but not quality) compared to the K3003i.  In particular, with a slight exception for the JH Roxanne, everything else sounded plain muddy in their bass.

There is more bass quantity in the JH Roxanne, but it is defnitely coloured and less articulate.



After doing many back to back comparisons, I also realized that the K3003i presents a tonally perfect presentation of the music.  This simply means that a pluck of a guitar string does not sound like a plucking an elastic band, and that foot drums do not sound like a bouncing basketball.  In this regard, all the tested IEMs failed except for the K3003i.  You may not realize this until you do the comparison yourself, but the K3003i is perfect here.  



The soundstage of the K3003i was very expansive, and immediately reminds me of the soundstage of my HD800.  In reality, the soundstage is closer to my T1, but for an IEM, this is the widest soundstage I have ever heard.

-From best to worst: 1) K3003i, 2) JH Roxanne, 3)Sony EX1000/JVC FX850

Yes, this beats my JH Roxanne custom IEMs.



In terms of vocals, the Sony EX1000 was my favourite because of it being very warm sounding, especially for female vocals.  However, the K3003i's wide soundstage and tonal accuracy makes the vocals sound very convincing and even more enjoyable vs. the EX1000's approach of colouring the presentation to make the vocals standout. The K3003i also has a certain depth and extension in the vocals that are not present in the EX1000.  The only reason I still have the EX1000 is for purely nostalgic reasons now.  



The AKG K3003i wins here with no contest.  Being the most tonally accurate and also the most articulate IEM in this group, the AKG presents instrumentals in a very musical yet detailed way that is every bit as good as my T1, but on a smaller scale.


A Note on Changing Filters:

Although three sets of filters are included to increase the treble, bass, or for "reference" sound, I found that I preferred the "reference" filter the most.  The other two filters are not as refined, and alot of Head-fiers echo the same sentiments too.


The "Reference" filter removed.  This is a simple threaded design.


*Other Comparisons

At some point in time, I owned the Shure SE846 together with the AKG K3003i, and have also listened to my friend's Sennheiser IE800 extensively.  These are three IEMs that alot of people will compare, and fortunately, I was able to do some of my own back to back comparisons between them.



The true strength of the SE846 is its very delicious sounding sub-bass, which is both very articulate and impactful, and feels like a real subwoofer in some ways without clouding up the rest of the presentation.  I did not enjoy the very confined and small soundstage of the SE846, and once again the tonality was not accurate and fairly coloured.  It was a unique and fun IEM, but clearly outclassed by the K3003i in all areas except for a textured, impactful bass output.



Best described as organic-sounding and musical.  The soundstage is also very large in this IEM, but not as large as the K3003i.  Like most Sennheisers, the IE800 is warm sounding and easy to listen to, but has less detail retrieval and clarity compared to the K3003i.  On the other hand, the bass on the IE800 may be a little better than the K3003i, but not by leaps and bounds.


Final Comments:

It took some understanding and comparisons for me to appreciate and fully enjoy the K3003i, but it was well worth it as this is now my favourite IEM.  The AKG is lightweight, easy to wear, and sounds as close to an IEM version of my HD800 as possible (without the overbearing sibiliance or shrillness associated with the HD800).  The fact that the AKG manages to trump my JH Roxanne (discarded) speaks volumes about the perception and the reality of high end equipment from large, established companies vs. smaller, emerging outfits that are only popular within niche circles.


When you buy the AKG, you are not buying it for the number of drivers it has, nor any special bells and whistles.  The K3003i is a meticulously engineered IEM that is phenomenal to listen to.  It is a true reference IEM in which its sonic qualities represents the best that I have experienced, while remaining fun and musical all the same.  The K3003i is so spectacular that it makes my Sony EX1000 and JVC FX850 sound like walmart specials, with the JH Roxanne sounding just average.  I have had these AKGs for over a year and also had many other IEMs and headphones come and go.  For home listening, I have a T1, HD800, and Koss ESP/950, as well as a set of Sehring S700SE boutique speakers. When I just want to enjoy the music without using my speakers, I often choose the Koss or these K3003i.  Yes, I use the K3003i even at home because it is that much of a treat. For the low price of admission of the K3003i today, you really owe it to yourself to try one of these out with a sufficiently good DAP. 


Happy listening!


Great review. I have the K3003's and T1's and enjoy them both very much. I am having serious issues with the cabling on the K3003's though; the shroud has come away at the earpiece revealing bare wire. Am trying fixes, but it really worries me, one snag and they'll be toast :-(
Lovely review, though I'm curious about your comment in the IE800 section about all Sennheiser headphones being 'warm sounding and easy to listen to'—are you including HD800 in this category?
Enjoyed your review of these IEMs - although I did not think they were as good as the IE800s. The IE800s have more detail and a warmer sound and a wider presentation. This is the bit I got stuck with. "The soundstage is also very large in this IEM, but not as large as the K3003i." The 3003i's have a more energetic feel to them than the IE800s. The IE800s sound more refined and more spacious
Let me clarify - I preferred the IE800s over the K3003is. The AKGs are a more accurate representation of the music to me. The IE800 is a more artificial one. The IE800 sounds more refined the 3003 more lively 
@salla45 I know that AKG will repair/sell replacement cables.  If anyone can create a detachable cable solution, that would be awesome!
@bosiemoncrieff The HD800 is definitely not warm sounding, but almost all the other Sennheiser headphones and IEMs I listened to are.  I feel that the HD800 is designed to be more neutral so as to sound more reference and are a departure from other Sennheisers in this regard.  When I have the perfectly recorded file playing through my CMA800R > HD800, then these headphones sound pretty amazing with the widest soundstage and the best dynamic range and detail retrieval.  The problem is, this is something that happens rarely, and I suspect that a proper setup for the HD800 to create a first-class listening experience requires components in your audio stack where the HD800 is the least expensive component!  
@Takeanidea In my back-to-back listening, the IE800 indeed proved to be very good.  To me, the AKGs have more detail retrieval, tonal accuracy, and a wider soundstage, but the IE800 was pretty close.  Perhaps the IE800 has a deeper soundstage vs. the K3003i with a wider soundstage, accompanied with the higher bass output of the IE800 and its more mid-range forward presentation.  The IE800, to me, sounds quite nice with vocals (albeit more coloured sounding) and the overall sound signature is smoother compared to the K3003i in my opinnion, with a tube-like sound.  It's interesting because I actually find the K3003i more refined, but the IE800 more energetic because of this.  For me, the accuracy of the K3003i's presentation and its wider soundstage makes it more preferable to the IE800, but both are top tier IEMs from respected companies and the technical differences between these IEMs are probably smaller than our personal preference of how the music should be presented.  I recall someone in the forums owning the SE846, IE800, and K3003i because they are different enough to have altogether. 
And in the end of the day:
JVC FX850 < ie800
ie800< AKG 3003i
AKG 3003i < Sony XBA-Z5
Sony XBA-Z5 < ak t8ie (mkI\mkII) 
I prefer the IE800 if I had to have one IEM in that price range. I loved the K3003i when I've heard it. But immediately I put the IE800s on I'm reminded why they are so great to listen to music on.
I managed to get a pair of cloned 3003s which come close to their sound. I agree with you on that they are totally different, it's probably unfair to say one is better than the other. They are both truly great earphones. Thanks for the insights. @RuFrost your reply makes no sense to me whatsoever. It looks like an equation and needs explaining 
Nice review.
Personally I'd never buy an earphone that has a permanently attached cable, regardless of their sound. I have the same opinion on the Shure KSE1500, and the AKGs have a much flimsier one, so not optimistic about this one.
Interesting review and comparisons. I love my K3003s very, very much. It's interesting to me that you didn't mention the (IMO) harsh highs of the K3003s. The first thought that crossed my mind when i first heard them was ''oookay this will be hard to get used to''. I have more than gotten used to it, in fact i absolutely LOVE the sound that it gives them. I still can't listen for very long without fatigue though.
Very nice review, but to clarify "....features a hybrid driver system with one dynamic driver and one balanced armature (BA) driver per side"

This is incorrect, each side has one dynamic and two BAs (triple hybrid). I truly love these and for 3 years they have been my go to IEMs. I recently came across the LZ-A4, same triple hybrid setup for under $200, bigger soundstage and simply stunning bass quality and detail retrieval. You owe it to yourself to try them. My k3003 have not left their leather pouch in quite a while (although I do still love them).
@Turrican2 You are correct.  I reviewed the manual again tonight and was reminded of the 3-way design.  Maybe I will give the LZ-A4 a try too.  The last time I ventured away from the K3003i and tried a Fidue A83, I was massively dissappointed and sold them pretty quickly. How would you compare the sound signatures of the two IEMs?
@Asiafood I did notice the extended treble at the very beginning too, but I don't mind them as it is very much crystal clear.  The treble was more fatiguing when I was using a DX90 as a DAP for the K3003i.  It was a great DAP with excellent clarity, but the sound signature was a bit anemic and treble happy.  At the moment I am enjoying music through a Headstage Arrow 5TX, which is highly customizeable (bass, treble, gain, and DAC ON/Off settings) and has a slightly warm sound.  
@audioscope not tried the fidue a83 sorry,
@Audioscope The treble is amazing in every way, no doubt about it. I use a Fiio X3 2nd Gen and a Fiio E11K. I have never heard anything else (except iphone 6 and HTC 10), but i've read that the X3 is a little on the warmer side. I think the K3003 performs incredibly well from those phones, the only improvement i notice with the Fiio DAP and amp is a little more full and dynamic sound.
@Turrican2 I think the Fidue A83 was not very good at all compared to the AKG.  There was no refintement and the soundstage was just not there.  What about the LZ-A4 vs. the AKG?  How do those compare to you?  
@Asiafood Haven't heard the X3, but I enjoyed the X5 as a reasonably priced DAP.  I suspect that the Fiio house sound is consistent in all their DAPs.  iPhone 6 played nice too - very smooth and a good pairing with the AKG.  I found that the AKG isn't terrible sounding even without the perfect file bitrates or a very expensiveDAP, and fairly forgiving, unlike some headphones out there.
The one more triple driver also features one dynamic and two BA which is coming in. So excited! Nice review. I saw these akgs on amazon and always wondered what's so special about them.
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