AKG K3003 Sound Quality - Grey Filters
Earphones of this grade are difficult to assess, because where lesser headphones can be defined by their faults, it's much harder to do so here. And we're not the gushing kind at TrustedReviews.
The best summation of the AKG K3003 sound is that it is exceptionally involving. The partnership of the carefully-tuned dynamic driver and the top-quality armature drivers that handle the upper mids and treble gives quite a different signature to triple-driver armature models.
The low-end is more expansive, superbly punchy and there's none of the treble roll-off that you'll find in Shure's top-end in-ear models. Soundstage is wide, imaging is excellent and separation is terrific. There's just so much detail and texture from the bottom of the frequency range to the top that you won't find a fuller-bodied and more assured performance from another universal IEM. Or at least, we haven't come across it.
Never has such a "no-compromise" sound been packed into such a small, innocuous package. It's enjoyable, it's well balanced and it's accurate. The one downside is that the top-end can be challenging with any music that's not well-mastered. For once it's not the fault the earphones themselves, but it doesn't change that harshness in recordings is relayed, where some less expensive but still great earphones are able to soften these sharp edges without creating the perception that they lack clarity of detail.
Of course, such unremitting accuracy is the whole point of a reference earphone. And the grey tip is what brings it closest to this holy grail of the earphone world.
AKG K3003 Sound Quality - White Filters
You might assume that the white, treble-focused filters would exacerbate this problem, but they don't. What they appear to do more than artificially increase the treble is to alter the weight of responsibility between the upper-mid range and top-end frequencies.
With the white tips, the weight is pushed further up the frequency spectrum, amounting to a reduction of mid-range presence. As any spikiness is also pushed into a thinner frequency band, any source harshness can be less apparent, but the overall signature is less satisfying. The sound remains highly impressive with wonderful separation, but there's an unmistakeable reduction in overall body.
AKG K3003 Sound Quality - Black Filters
The black "bass" filters pull a similar move, but this time the onus is pushed downwards, with an increased low-mid presence. This in turn increases warmth, which as a whole pulls attention away from the top-end.
As with any warm-leaning earphone, though, an increase in warmth does lead to a certain thickness in the sound that just doesn't compare with the lean muscularity of the "reference" grey filters. Low-end bass performance doesn't seem to be particularly improved, either. It creates a swell that's pleasant, but in technical terms doesn't benefit sound quality
AKG K3003 Verdict
The AKG K3003 are probably the best universal fit in-ear headphones in the world right now, and they can compete with some of the best customs too. They excel in every sonic aspect - soundstage, bass response, detail, balance and imaging/separation - especially when used with their "reference" sound customisation tips. Construction is superb too, all-steel and yet offering perfect weight management. The lack of a removable cable makes them feel a bit like an earphone equivalent of a concept car, but contrary to what you may assume, they do wipe the floor with most £200-300 earphones.