QKZ AK6 Day Earphones Review – QKZ’s Ultimate Vocal Champion

First Impressions

The QKZ AK6 Day comes in the usual QKZ black packaging. 

Out of the box, I thought these IEMs looked like the KZ EDCX minus that shiny finish. The AK6 Day comes with basic accessories: three pairs of stock tips, an ear clip, and silicone ear hooks. 

The cable is non-detachable, which could be a problem in the future if they break since I won’t be able to replace them. But for around $5, I’m not complaining because I can easily just replace the entire set.

The first time I ever tried this set was after briefly testing out the CVJ SD1 IEMs and they were honestly on par with each other. 

Like the SD1, the QKZ AK6 Day was quick to flaunt its vocal forwardness and prowess. Its main difference with other QKZ IEMs is that the midrange isn’t only clear but it’s tuned to be expressive. 

It’s puzzling how noticeable this detail was just from the first listen but to be fair, it was a short session of extreme critical listening. 

Build Quality

The build quality on the QKZ AK6 Day is pretty good. 

Like most QKZ sets, it’s primarily made of plastic but it feels sturdy because of the resin-like faceplate. It’s not exactly resin though because when I tapped the faceplate, it made a very loud ticking sound instead of a diffused and fainter sound. 

The quality of the cable is also good. The cable lines up in a two-file fashion – very much different from the rest of the AK6 series. 

There’s a little bit of microphonics when you accidentally hit the cable and that’s because of the plastic insulation covering it. This isn’t really much of a problem but since the cables are soldered into the drivers themselves, any kind of cable swapping is not possible. 

All in all, I like the build of the AK6 Day. It’s less fragile because of the faceplate and the cable allows for some heavy use – just keep them away from something sharp.

Fit and Comfort

The fit of the QKZ AK6 Day is exceptionally good. 

The included silicone ear tips didn’t even need to be swapped out because they fit my ears well with the exact kind of seal I prefer. 

Comfort-wise, they didn’t cause any pain or discomfort even when I was using them for long listening sessions. They’re pretty light to carry. 

The only downside is when I wear them on walks, the microphonics are pretty noticeable because of how light the cable is. A thicker, braided one would’ve fixed this but it’s not possible because it’s not detachable. 

Aside from this minor gripe, the QKZ AK6 Day presents no other problems in this department.

Sound Quality

The QKZ AK6 Day is a warm set that has a W-shape tuning. This kind of tuning means that all three frequency bands sound emphasized. 

This isn’t to be taken too literally as the emphasis on all three sound bands would result in an utterly shouty and unintelligible playback response. They’re all emphasized to specific degrees and with the AK6 Day case, it’s done exceptionally well. 

The bass is something a bass head would approve of while still possessing decent speed. The midrange is lush and expressive and is forward in the mix. The treble has a great extension with a little bit of roll-off making sibilance non-existent. 

This is a pretty cohesive tuning in my books and would’ve been something I wanted to know back then before buying my more expensive sets. 

Bass 

The bass on the QKZ AK6 DAY has good quantity and is generally present on almost every track. 

It’s not intrusive like the ever-present bass tuning a lot of cheaper IEMs opt for but has a good presence whenever it’s needed. Unlike other sets that hide and jump out when needed, its bass leans more on the side of being readily available for deployment. 

The texture is decent but lacking a little bit due to a slight timbre bottleneck. The mid-bass speed is fairly good and has good punch and slam dynamics.

Midrange

The midrange is forward but unlike other sets, it doesn’t bet all its cards on vocal clarity. It’s tuned in a way that’s expressive and articulate.

The lower midrange energy is on point, providing tracks with much engagement, while the upper midrange is boosted just enough to highlight the highs but not to the degree that would make voices shouty.

This kind of midrange tuning is hard to achieve and at this price range, it’s impressive that the QKZ AK6 Day managed to do it.

Treble

The treble is well-extended, rendering transients crispy and giving playback some splash and sparkle.

There’s no sibilance in this treble tuning but I’m a little dissatisfied with how cymbal hits decay. I’m not exactly sure what’s causing this but something is preventing the transients from sounding as life-like as they could be. 

Overall, the treble performance and cohesion on the QKZ AK6 Day are great, especially when reeling back in the factor that it’s a $5 set.

Test Tracks

These tracks are more for the purpose of testing rather than song and unit synergy. 

I find that these tracks are effective at distinguishing specific details about the tuning and will provide better insight into how these IEMs sound.

• Fake Out by Fall Out Boy (Alternative/Indie) – The timbre of the QKZ AK6 Day was good in the first part of the song and served as my benchmark for midrange timbre. It wasn’t noticeable to the unfamiliar ear but it sounded a little off. The vocals sounded energetic and forward, and the lyrics were heard. The presence of bells was there, the tambourines and snares sounded crispy, and there was no sibilance. This is a good performance overall.
• Cupid (Twin Version) by FIFTY FIFTY (K-POP) – The sweet serenade of the intro was done well with good intonation and expression. This version of the song was speedier and well-suited to the bass response of the AK6 DAY which presents a deep and thumpy playback. The high notes were very mellow and bright as they tied in nicely with the main vocal line. Again, instrumental timbre seemed to be below my expectations but as far as overall enjoyment, it was a minor gripe at best. 
• Salamander by DECO*27 Cover by Ivudot (Vocaloid/J-Pop) – The vocal layering and instrument separation was good on this track. In tandem with sparkly transients and fast drum beats, the whole playback was a rollercoaster of addictive listening that paid homage to the kind of energy and excitement vocaloid productions present. This song is a cover with a male vocalist, and it lost its original high-pitched vocals in exchange for mellow and yet weighty male vocals that were articulate without being heavy. This accentuated that male and female vocals sound great on the AK6 Day.

Conclusion

The QKZ AK6 DAY is something of beauty at its price point. 

With its sonic capabilities and aesthetics, it definitely redefined the whole AK6 landscape. And with this, I officially retract my statement about the AK6-X being the best in this product line. 

There are a lot of sets in this line and I’d be surprised if anything tops the AK6 DAY further. 

With this set, the bass response is bass head certified with good speed and elasticity. The midrange is forward and has great articulation but comes with some minor timbral issues. And the treble is detailed and rolled off just right where it needs to: the sibilance areas. 

Caveats like the timbre and microphonics are minor and aren’t a deal-breaker.

It’s hard to find fault with the QKZ AK6 DAY and it took long hours of critical listening to pinpoint some flaws.

Overall the price-to-performance ratio is crazy good and I regard it as having one of the most pleasant midrange performances even when compared to more expensive sets.

This post was last updated on 2025-03-19 / Some images from Amazon Product API & some links may be affiliate links which may earn us a commission from purchases.