Ivan's Bri3fcas3: 2017

Disclaimer: This review is written based on a normal listener (a.k.a not audiophile) and I believe that everyone has a different listening experience. My listening preference is balanced sound and treble-happy (I enjoy clarity over bass). My listening setups are Flac file format, Samsung A7 smartphone with Poweramp, laptop with Dolby Advance sound plus foobar2000.

Short Summary

Cons

Subpar construction quality.
Screw-on housing has no purpose and doesn't enhance the aesthetic (personal opinion).
Imbalance channel (The right side is louder than the left)
Piercing treble if paired with a headphone amp.
V shape sound characteristic. High treble and bass. Mid-range frequency is tad laid back.
The bass is a little artificial, especially the bass drum. A bit more rumble and bloated.
Sound leak and average isolation.
Rubbery cable plus edgy housing causing discomfort.
Large housing may not fit people with small ears. Not comfortable for long listening.

Pro

Dual Balance Armature produces detailed sound characteristics. (if you don't mind the sibilance)
Very good price-per-performance ratio. 4 drivers (dual BA + dual dynamic) with price less than $30.
Easy to drive with a smartphone. A headphone amp is NOT recommended.
Replaceable cable.
Aluminium housing.

Long story

After reading the online reviews and most of them reported with a positive conclusion, I finally bite the bullet and order a pair (with android headset cable) from Gearbest with AUD $29.37 including shipping.

Afterall, 4 drivers in-ear-monitor with price less than $30, what could go wrong?

After 5 weeks of waiting (impatiently) and finally got my hands on the earphone, things start to go horribly wrong.

Quality Issue

The first thing I noticed is that the left earpiece cover is a bit loose. I thought this is a small issue as the screw on the housing was loosened. So I try to tighten up the screw but it has no end. It seems to me that there no internal thread and caused by manufacturing issue. Then I thought maybe I tried something else later to jam the screws but they are so loose that I ended up losing one of them. Disappointment plus frustration, instead of sending back to Gearbest for the repair (more waiting), I went to the nearby stationery shop and get a $3 superglue to end this frustration once and for all.

Both screws do not hold up the cover. One end up missing and the other I kept it in a safe place.

Aftermath after putting the superglue. A "scar" between the top cover and the housing. It's not perfectly aligned but the seal does not matter because there is a bass port on the cover.

Please be warned this earphone I got has a physical quality issue. Or perhaps it was just me who happens to be the unlucky one.

Furthermore, the screw on the housing doesn't enhance the earphone aesthetic nor provide any advantage to the listener (e.g. bass/treble tuning). In my opinion, I don't think anyone would unscrew the cover and do something special about it. If you are a KZ engineer or designer, please throw away the screws design and have it clip-on on the housing.

Right earpiece has no issue.

Another quality issue is the cable connection gap is different between left and right earpiece. There is a slight gap in the right cable connector while there is none on the left (See screenshot below). I have tried to push in hard but it won't budge any further. Fortunately, the connector stays in place and does not fall out easily.

Left & right connector looks the same.

There is a gap on the right connector but there is none on the left.

Then, there is the rubbery cable that is easily picked up microphonic noise (e.g. cable rubbing on a shirt while moving) and the memory ear hook does not help to stop the noise much. Furthermore, the rubbery cable irritates my skin when I tucked the cable inside my t-shirt. In short, I don't really like the cable much. However, cable splitter, L shape 3.5mm plug, and the headset controller is well built.

The housing is made of aluminum and it's big compared with others similar earphone I have. It carries some weight and eventually caused some discomfort after long session of listening. People with small ears will definitely have difficulty on the fitting.

Sound

On my first listening, I noticed there is an audible channel imbalance where the right earphone is louder than the left. I used my smartphone to run a pink noise check with 80% volume and I can confirm that the imbalance is real. Adding more salt to my KS6 injury. Ouch. However, low volume listening might not able to notice the difference.

On the bright side, KS6 is my first pair Balance Armature (BA) earphone and it does really bring out the details in a song, up to a point where I can imagine the song environment (e.g. reverb, echo, guitar string picking, live concert ambient noise). With a headphone amp (Fiio E11 Kilimanjaro), KS6 shines until that the treble went overly bright and hot, resulted in some of the reviewers reported hissing/sibilance with this earphone, which is true.

Please be warned that sibilance effect on electronic genre song is the worst of all where high pitch electronic sounded annoyingly buzzing and piercing. Never in my life that I have experienced this before.

Luckily, to remedy this issue, I got a Samsung Galaxy Tab P1000 (with voodoo sound app), which has fall-off starting from the 20khz treble region. Without headphone amp, it pairs really well with KS6 without too much hissing/sibilance except it reduced sound imaging. Another workaround is low volume listening will help ease the sibilance issue. I have tried using comply foam tips for toning down the sibilance but it doesn't help much.

Next is the bass region which I find it a bit artificial, bloated and rumble. Some might even enjoy the coloration. After a long session of listening, I'm not compelled to tune down the bass so I guess it is acceptable.

Soundstage is above average but not spaciously wide.

Overall sound characteristic, in short, it's a V shape with high treble and bass. Mid-range frequency is a tab laid back but doesn't overrun by the bass or treble. Instrument separation is superb and surpass my other earphone collection (All non-BA).

I have tried equalizing it to my preference by tuning down the treble and bass for a better sound balance but I find it hard to control.

Isolation is average and the bass port on the housing will leak sound but not enough to annoy other people in public transport unless they sit really close.

Conclusion

So in the end, how's KS6 performed? In my opinion, this is the first earphone review that I put up a Not Recommended. To be honest, I had high hopes on KS6, as Chinese companies nowadays are producing high-quality products (e.g.XiaoMi, Huawei). However, this KS6 that I have gotten does not live up the hype from reviews I read on the Internet. Well, we can all argue if I get a replacement, my experience might change to a positive note. But I would rather move on than deal with the quality issue.

On top of that, here are some points to ponder:

Is channel imbalance a deal breaker? For me, yes.
Is potential sibilance presentation a deal breaker? I can work around it but not ideal.

The only joy that I can get out from my pair of KS6 is that the BA sound signature comes with lots of details and clarity, differentiating itself from my other earphones with its own unique listening experience. So, it's a keeper for now until I find another pair of BA earphone (perhaps KS6 version 2?) that can match up with KS6, then it will be stored away.

Update: After couple of week of listening, the bloated bass start to becoming a problem, sounded unnatural. It's affecting the sound quality when watching video or youtube and some of my favorite tracks. I even bought the silver cable just to see whether that help improve the sound quality and channel imbalance. Unfortunately, that didn't work either however, it is more comfortable for the skin and less microphobic issue.