AKG K3003

The AKG K-3003 is at least close to a landmark Universal IEM, in my view. Pricey, yes, but one of the first Universals to aspire to the heights that the best of the Custon IEM's aspire to. They are well built (though some may not like the idea of non-detachable cables) and attractive enough. But the real issue is, of course, the sound, so let's get right to it.

The first thing that hit me about the AKG's is that they invite comparison to full size phones in certain ways more that other IEM's. The combination of excellent coherency top to bottom, excellent but not hyped detail and resolution, low distortion, good dynamics and relative neutrality show up even good IEM's such as the Sony MDR-EX1000, Audio Technica CK-10, Ortofon EQ-7 and the like as pretenders. Let's take some of these features forward for further scrutiny.

Coherency 

These sound quite consistant as a solo instrument (piano, violin, guitar etc.) is played up and down the key/fret board. Lesser IEM's will tend to, worse case, sound uneven in amplitude or, less destructively, thin or fatten the harmonic envelope (this is where our ability to discern instruments of different model/construction comes from) under these conditions. A good example of this is the album The Virtuoso Guitar as played by Alirio Diaz on a Vangard recording. If the guitar doesn't sound like the same guitar through its range, the illusion of an expert musician playing his instrument is damaged. This coherency pays off even further during the Castelnuevo-Tedesco Guitar Concerto #1 off this album where the interplay between soloist and orchestra is preserved.

Detail

The high linearity (low distortion) of the 3003 allows one to hear deep into the lower levels of recordings without the masking effects of distortion products. This allows low level information to be heard in the mix of popular music or orchestral presentation. This allows things like the "humming along" Ivan Moravec provides in his VAI label Beethoven recordings (original on Connoisseur Society) or the various sonic manipulations on the Beatles "Strawberry Fields" to be heard clearly for what they are. This detail is not the "thrown in your face" detail of certain treble emphasized phones but is an organic part of the recording not obscured by transducer playback artifacts.

Dynamics

This is where the 3003 really excells over lesser IEM's. The combination of lack of low level artifacts and high (for IEM's) level linearity makes for a wide dynamic envelope. The Fritz Reiner RCA recording of "Isle of the Dead" (off "The Reiner Sound" album) is a great example of this. This recording starts very much hushed (as befits a piece called Isle of the Dead) but swells to quite loud crescendos. The AKG's can accomodate this without distortion (beyond the slight tape saturation on the highest peaks endemic to the otherwise excellent late '50 recording) or without compromising the soundfield by coagulating the instruments together, quite a feat for an IEM. Careful, don't listen too loud! The low distortion and high levels attainable can lead to this...

Relative Neutrality

I use this term because I am not sure what absolute neutrality would be. Neutral to the recording? Neutral to the original sound of the original performace? Neutral to some preconsceived idea how a phone "should" measure? Neutral to the your personal preference? Or some combination?

The AKG tends to be neutral to the recording, which tends to result in a somewhat front-of-the-hall perspective. Still neutral to the original performace, but some may like a bit of a more distant perspective as personal preference. One of my tests for the "gestalt" of the concert hall is the EMI recording of the Barbirolli Mahler 9 with the Berliner Philharmoniker. This is a good, but somewhat forward, recording of an excellent performance of this evocative piece. If the playback puts you into the hall without putting the forwardness "over the top", it's good playback. The 3003 does this, to be sure.

For further evaluation, let's go to the classics. I personally use Iggy and the Stooges "Search and Destroy". This is a recording made with the VU meters pegged, as it should be! An IEM that can deliver the swagger, threat and excitement of this is doing it justice and the AKG does it justice, in my view. A particular favorite group of mine is the sound world of The Legendary Pink Dots. The combination of the Silverman's swirling keyboards and Edward Ka-Spel's wispy lyrics and vocals (inside joke) make for music that can take you to some less-visited places inside. The fact that I can be sitting on the train on the way home from work and still escape to the Dots' world is as good a recommendation as I can give.

Bottom line. Between AKG, Final Audio Design and various of the custom designers the IEM has been brought into higher levels of performance than ever before. Here in the States, one has to give credit to Ultimate Ears and JH Audio for pioneering the idea that custom IEM's can aspire to greatness and that audiophiles would respond to the performance by paying the price. And now we can thank AKG and Final Audio Design for believing that those of us who don't want customs would also pay for high performance.

Some will balk at the 5 star rating for value. The K3003 are indeed not cheap, but I know of no way currently to get equivalent performance in a universal IEM at a lesser price. To me, that's priceless.

EXECUTIVE SUMMARY

1.      Not coherent throughout the audio band:

a. Overall neutral, but but but

b. What’s up with the peaks in the upper mids/lower treble?*

c. Little bit bloated in the bass

d. Bass not keeping up with the mids/treble

2.      Little bullet design = comfort/fit that blows monkey chucks

3.      Mid-fi resolution

4.      Aren't IEMs supposed to isolate?

Significant sonic issues indicated in red.

* Pop and rock do not sound good. However your results may be better with classical or music with acoustic instruments.

Treble: a little bit piercing, especially on IPC. However, if connet this with the Hifiman player like HM-602, HM-603 or HM-801, the treble would be bright but not piercing.

Mid: clean and natural. Some might say it's lack of warmth, but with a warmth sound music player, the mid will be warm and full of emotion.

Bass: when I bought this, I thought this IEM lack of bass. After run for longer than 700 hours. It has much better perfomance on bass, especially the depth of the bass.

Soundstage: the only word to discribe the soundstage of this IEM is UNBELIEVEABLE. I just can't imaging an IEM can have this range of soundstage. 

Imaging: Amazing, just like the perfomance on the soundstage. I can clearly feel the different locations of all the music instrument.

Vocal: very natural, slightly forward. clearly seperated to the accompany. clear and bright, might feel lack of warmth with some player.

Comfort: I have to say, the K3003 is very comfort for me, but not for the guys who have narrow ear canal.

Isolation: the isolation of this IEM is not that good, but still better than many IEM, after use the Comply foam tips, the isolation getting better.

About the dynamic and balanced armature units: I have to say, the K3003 is the best hybrid headphone I've ever heard. I think the coherency is quite good.

Gears used: HiSoundAudio Studio V, iRiver AK100

Tracks used: SoundProLab Absolute Sampler Album

                    Kamikazee's Maharot

                    Mary Stallings, Sunny

                    All in Lossless CD Quality 44khz/16bit

Value:

I think this is a great value for an IEM, to have this kind of sound quality yet very portable to carry around is just amazing. If you can save up to buy these they are definitely worth it.

Audio Quality:

I am not very technical so I'll just share you in a way that I can.

Transparency:

I think this is where the K3003 shine the most, It was able to provide layers and separation in all notes, not too many IEMs can do that specially at the low frequencies, other IEMs tend to sound distorted when a set of bass level instruments are produced simultaneously, with the K3003 the lows from drums, bass guitar, and rhythm guitar are significantly heard separately. The mids and highs are like that as well.

Imaging:

The presentation is simply amazing, you can close your eyes and imagine where the band is playing whether the music was produce to sound as if you were in a bar with a small stage or a large concert stadium.

Soundstage:

The largest I've heard on any universal IEM.

Sound Signature:

Very very very natural, very similar to Beyerdynamic T1 which is my favorite full sized headphones. Everything you will hear in K3003 is very real, the drum hits are just unbelievable, the guitar strings sound as if you're the one playing them, you can even hear the singer's lips open. I am not exaggerating this.

Bass:

Great but its just a couple notch to becoming excellent I just want a little more punch and a little more bass extension but very little.

Mids:

Great, maybe excellent if we are only comparing with IEM.

Highs:

Excellent, the most pleasurable highs I have heard, very clear but not fatiguing.

Comfort:

I guess if I can pin point a problem it will be the comfort, well its not actually uncomfortable but you get the feeling that the IEM is losing its grip inside after awhile but not really.

Isolation:

4 stars because of the comfort problem that I mentioned, this is with comparison to Westone silicon tips that locks up instantly without any effort.

Overall:

This is the best universal IEM that I have heard so far. I may come bias since I have not heard other expensive earphones available in the market other than the Sennheiser IE 800 and Westone 4R. I am very familiar with the headphones Beyerdynamic T1 and Sennheiser HD 800. Sure there are a lot of portable gear setups that can surpass the sound quality that you can get from a mere set of earphones and a dap, but hey its a mere set of earphones and a dap!

Short Review: All observations made with the high pass filters. Naturally I listened with each of the three filters, but the high pass was my preference.

Pros:

I really liked the tuning of these. With the K3003, you get an approximation of a neutral sound in terms of a good balance between treble, midrange and bass and the filter system gives you a means of adjusting this balance (at a cost of slightly loss of detail with the non-reference filters). What's great is that the sound is still very fun. I'm not sure I can put my finger on exactly why, but these were great to listen to. I think the combination of the brightness of the treble with the full bass give the fun of a more v-shaped sound, but I didn't find the midrange recessed. Add that to the nice detail in the midrange and treble, and you've got a tuning that lets you sit up an really listen to your music while still rocking out.

Cons:

The main issue for me was the incoherency between the drivers. You can certainly tell the difference between the sound characteristics of the dynamic driver for the bass and the balanced armature drivers for the midrange and treble. I'm not sure why AKG used this particular dynamic driver, but it's markedly less detailed and has a slower decay than the armatures. It's not terrible, but it's a serious flaw in an earphone with a huge pricetag. I often listen to music where the bass, midrange and treble are equally balanced, string quartets are an example. Another is renaissance polyphony where the bass, tenor, alto and soprano singers must be balanced. The bass voices were less detailed and crisp than the sopranos with the k3003. I imagine there will be music where this issue is less noticeable, but if you listen, you'll hear the discontinuity in the earphone.

EDIT: After writing the review, I've come across a graph which may help: The CSD graph in this post perfectly sums up the issue with the k3003. You can see very clearly that the decay in the bass from the dynamic driver is way, way, way longer than in the rest of the frequency range as produced by the armature drivers.

The treble will definitely be a bit harsh for some using the high pass filters, but using the other filters takes a bit away from the detail resolution. It's a trade off that I don't want to make at $1,400.

Some found issues with isolation, I thought it was average. Others have reported fit issues, I didn't have any, but certainly it's always possible and one can carefully try different brands of eartips. The standard tips worked for me so I didn't explore that.

Reliability is a serious concern as well. The stress relief on the pair I used for this review was showing signs of wear after only a few months.

AKG K3003

Before jumping into the sound, I want to make a few comments on build and accessories, which I feel are important to discuss, due to how they may affect the sound and/or durability of the product.

Accessories include 3 pair of stock single flange tips that are very comfortable and well made with a good combination of thickness and flexibility.  My only issue with them is that I require a bit deeper insertion due to the shape of the housings and tip length; I can’t quite reach optimal positioning.  I had some extra Meelec triple flange (trips) tips lying around and these solved the fit issue.  Achieving optimum fit smoothed the treble out, improving its tone and realism, while tightening up the low end a fair amount.  Another benefit was the expansion of soundstage from left to right and improving imaging.  I would like to see AKG offer some dual and triple flange tips of the same quality of their single flanges as the changes I heard in sound were significant for me.

Other accessories include screw on swappable filters (bass, treble and reference).  The bass filter is basically useless.  It really muddies up the sound, wrecks clarity and timbre and just plain sounds bad.  The treble filter offers a very nice analytical sound that is very reminiscent of the Audio Technica CK10 and is overall more neutral.  The reference filter, which is my preference, slightly pulls back on the treble presence, while adding a very satisfying bass presence.  The build quality of the housings and filters are excellent and beautifully crafted.  I love the smart screw-in mechanism of the filters.  The housings are surprisingly small and tastefully minimalistic in overall design.

If there is anything to fault or complain about, it is the cable; in particularly the section of the cable above the Y split.  On the microphone version, there are no strain reliefs around it and I find where the cable enters the strain reliefs on the housings concerning as well.  Perhaps it is unfounded concern but these do appear to be weak points in an otherwise well built and very expensive, top of the line earphone.  I think I would have preferred the upper portion of the cable to be covered in the same nylon feeling material of the bottom portion, allowing for more flexibility without kinking at strain points.

Also suspect is the winding case.  While very attractive looking, I find winding the earphone in a large square shape to be impractical and creates odd memory to the cable;  but more importantly the method for storing the housings in the case seems overly complicated and could lead to kinking or damaging the cable, if one is not very carful.  An aftermarket case, like a Pelican, Otterbox or UE hard case is recommended.

Enough with the cosmetic and on with the sound.

Being that the K3003 is a hybrid design, coherency between the differing driver technologies seems to be one of the biggest concerns; so let me start by saying, to me, it is a non-issue.  I think the driver technologies are blended very well and I did not find anything distracting or disjointed during my listening sessions.  Instruments sounded smooth and cohesive from the bottom of the scale and up, contributing to excellent timbre.  Coherency Schmoeherency.  Just enjoy the music because it sounds damn good from the K3003.

Coherency Schmoeherency as performed by Van Halen.

The treble of the K3003 is simply fantastic, nicely weighted and has a very nice brassiness about it.  It is highly reminiscent of the CK10 treble, albeit a slightly tamed down version of that treble.  With the Meelec trips, I’ve had no issue with undo sibilance or issues with peaks or harshness.  Just airy, brassy and extended goodness.

In comparison the Merlin and UM3X treble are much more subdued and laid back.  The UM3X treble is not only more laid back but also sounds less realistic, with less detail retrieval than the K3003.  Upon switching back to the UM3X, it’s takes a moment to readjust, making the UM3X seem a little too dark and smoothed over.  The Merlin treble is also more laid back than the K3003 but is certainly crisper and more present than the UM3X.  Both the Merlin and K3003 high end come across as highly detailed and resolving, especially when amplified with the cleaner signal of the Leckerton UHA-6s mk2, but over all I enjoy the treble presentation of the K3003 more.  It’s the CK10 like brassiness and realism that won me over.

The midrange of the K3003 is slightly forward and aggressive with a flavor I would term as sweet. Vocals are very engaging; strings sound lifelike and distortion guitars have excellent bite.  This energetic midrange presentation is right in my wheelhouse of preferences and is one of the most likeable traits of the K3003; in fact I think I’d call the K3003 mildly mid-centric.

In comparison to the UM3X, the K3003 displays much greater upper mid presence, which is what gives it the aggressive and sweet sound.  The upper mid of the UM3X is actually scooped out, with more emphasis on the lower mid, giving it a more lush, euphonic or analogue sound.  Both presentations are great but I’d say the balance of upper and lower mid presence gives the K3003 more versatility for a better all rounder and certainly gives it greater clarity.

On the other hand, the Merlin seems to split the difference between the mid presentation of the UM3X and K3003.  In my Merlin thread, I compared the similarities between the RE262 mids and the Merlin.  The K3003 mids are more aggressive and sweet sounding than the Merlin still, due to more upper mid presence.  The Merlin gives a more emotional, intimate vocal by being more laid back than the K3003.  I also find the midrange of the Merlin to be more resolving of micro-detail, especially with the Leckerton or Arrow 4g amps.

The bass of the K3003 can be summed up a number of ways - fun, satisfying, impactful, deep, textured and musical.  If ultimate neutrality is your goal, you won’t find it with the dynamic bass of the K3003 and the reference filter, although its boost isn’t as large as the overwhelming majority of consumer oriented earphones.  The amount of boost the K3003 offers is quite possibly the perfect amount for my preferences.  It adds realistic and believable weight to strings and keys and I could not detect any issues with bleeding into the midrange.  While certainly not as fast and as accurate as say, the CK10 bass, it is fast for dynamic driver bass and is tastefully colored and very lifelike.

In comparison to the UM3X and Merlin, the K3003 has less bass quantity, coming across as the most neutral of the three.  The K3003 beats the UM3X in lower end extension and resolution, while the Merlin has more of its bass focused on deep/sub bass, so it gives the feeling of greater extension and rumble.  With the Meelec trips, the tightness of the K3003 bass competes very well with the Merlin bass, both being some of the tighter dynamic driver bass I’ve heard. 

With the stock tips, I thought the K3003 soundstage width was just average to perhaps slightly above average but with a spacious and airy presentation within that soundstage, displaying much better than average depth.  With the Meelec trips, the soundstage is increased from left to right by a substantial margin to my ears.  Comparatively the Merlin soundstage is still wider and deeper but a fair amount taller as well.  The Merlin soundstage is the tallest I’ve heard to date, although with the Meelec trips, the K3003 soundstage is very satisfying.

Imaging and separation are as good as the best, or better than I’ve heard in most universals.  Dynamics are also excellent and the K3003 makes a superb low volume listening experience, and is in fact the best I’ve heard yet for low volume.  As mentioned earlier, timbre is very good - strings and keys sound lifelike and believable, with proper note weight; toms and snares snap to life; cymbals and rides have a natural brassiness.  The K3003 is one of better phones for portraying instruments as you would hear them in person.  I would love to be able to compare these to my previous timbre champs, the EX1000 and FX700.  It seems to balance nicely between earphones that come across as too thick or too thin in note.

Value

While I absolutely love the sound of the K3003, I do find the price point impractical for myself; but I am hoping AKG prices the K3003 more competitively in near future, as other companies release new hybrids and new flagships this winter.  If so, I would definitely be very interested in obtaining my own set.

Conclusion

If I had to sum up my listening experience with the K3003, I would call it a CK10 with dynamic driver bass.  It takes the same great, brassy treble of the CK10, tones it down just a bit; sweetens up the midrange and lifts it slightly; then adds a more subdued taste of the Merlin bass.  The majority of the music I listen to is distortion guitar driven rock with a healthy does of acoustic/indie/singer-songwriter selections - and it is without reservation that I can say the AKG K3003 rocks; but it does so much more and truly sounds excellent with everything I send its way.

Big thanks to Bizkit!

Review re-posted here.