The ED9 is overall a good and very funny iem from China. 
 
 
 
build + design:
The metal housing shows confidence and it looks like it won't break for a long time. I did like the looks overall (but the color of the cable is ugly in my point of view). No driver flex, which is very good from a low-budget iem (oh I remember you, AWEI). The cable is noting special, but the plug didnt fit very well in my Sony M4. Didn't have the chance to try it out with other phones, but  I used a bunch of IEMs with this phone and they did fit fine.
 

 
 
package + accessories:
the acoustic filters are FUN! at first. They come with 2 acoustic filters which changes the soundpicture completely, one highlights the bass and one is kinda like a reference filter with no filter at all (at least I guess so since no instructions came with the package which is a shame and a big black point for KZ). I liked the bassy one a lot more: the reference one was too boring for me (no bass, no dynamic, less fun) but IMO a lot of bassheads will like the bassy one since it surely has tons of deep and bass. It has 2 pairs of filters and 3 pairs of silicone air tips. The package is plastic and can be used as a bag if you remove the accessories from it which is a great idea.
 

 
 
SoundQuality: I spoilered it at the acoustic filters: overall I did like them very much (for 9$ very-very good SQ), a little too much deep for my taste, so be careful, if you like neutral or balanced EQ then use the other filter. The soundstage and the details very better then expected (yet again, for this price): this one is surely a fun thing to use.
 
for this price I would recommend this IEM to everyone who likes to experiment, looks for a decent, metal housing earphone or just likes a lot of bass: value/price ratio is 5/5. Recommended.

I am a music lover and an engineer by profession
Things I own:
Fiio X1
Shure SE215 in ear
audio technica ath-m40x
Harman Kardon IENC in ear
Harman Kardon AE in ear
JBL TMG81BL Tim McGraw Artist Series On Ear Headphones
Knowledge Zenith (KZ) ED9 in ear
AKG K451 on ear

I happened to stumble upon this by mistake on head-fi and thought lets order one. 13$ there is nothing much to loose.

Packaging: Good

Build quality: Wow, did not expect that for 13 bucks. Solid Steel casing, Great solid wires and Brass Tuning nozzles.

Audio Quality:
I use my fiio x-1 to test any earbuds or headphones with some excellent flac flies (lossless music files). I usually connect my earphones to lapop and play a 20+ hour play list to ensure new earbud or headphones burn in.

I dont love extra bass in my music. I enjoy music the way it is without any altercation. So I switched onto the filter less nozzles (No User manual by the Manufacturer to differentiate between the nozzles. The one with black filter on it is extra bass)

Post a day Connected it to my Fiio X-1 and started with my favorite song, Riders on the storm (The doors), Oh man I was blown away. I was getting the feel that these earbuds gonna be my favorite ones.
I was skeptical about the fit, I get cranky when earbuds dont give a comfort fit and with 13$ i was really not expecting a good fit. (I hate silicone tips as they always give me an annoying fit. So changed the tips to Memory foam). With Memory foam tips on it, I can say they are quite comfy and give adequate noise isolation.

After playing some Jazz, played some adele songs (I love her voice and I really love good vocalists). Then turned on to MJ thriller album. I was blown away. They reproduce the sound the way it is no added bass perfect lows and mids.

I doubt they get better with more burn in, I already have played good 60+ hours and no change. As it is they are just perfect.

You cannot go wrong with this.If these were made by any other famous brand, they would be selling it for 100-150$).

Build Quality: 5 stars
Audio Quality: 5 stars
Pros: Everything
Concern: No instruction on Nozzles, Some of the members have posted concern on QC (I did not encounter any)

Suggestion: Keep good music source and quality music files

Conclusion: If you love good music and you want something under budget, here it is. T

Knowledge Zenith (KZ) ED9 - Another contender for the 'Best Value'?
 
 

 
 
Specs:
 
Frequency Response: 7-46200Hz (?)
Sensitivity: 108dB
Input Impedance: 18Ω
 
 
 
Price: not sure about the retail price, but it goes under $20 (or even under $10) 
 
 
Accessories:
 
4 pairs of silicone tips (1xS, 2xM, 1xL)
2 pairs of interchangeable nozzles
 
 

 
 
 
 
Design:
 
The KZ ED9 model looks quite nice on its silver and gold mix; silver housings and golden nozzles, both made of a certain metal alloy. Strain relief is flexible but a bit short. Cable a bit rubbery, doesn't hold a memory effect, but is kind of springy and average on microphonics. The plug looks well made from the outside, but can't really say about the internal QC, as some noise was noticed at times when just touching the plug.
 

 
 
              
Fit, Comfort and Isolation:
 
No issues here. The housings' shape is rather straight, not too wide or long, so the fit is quite easy. While they do feel just a bit heavy on hands, they stay fixed once on the ears without any discomfort.
Isolation is quite good. The large vents on the back don't seem to have any negative effect. I'd say isolation is about same level of SoundMagic E50/80 and Hifiman RE400.
 

 
 
Sound:
 
There've been many good impressions about the high SQ performance of the Knowledge Zenith earphones for their very affordable prices. While this is the first KZ model I get to try, I can now confirm what the whole 'hype' is about. For something that goes below the $20 range, the ED9 offer a really good sound, not just for 'quality for price' alone, but as a whole musical experience.
 
While the ED9 feature exchangeable nozzle, the overall signature leans towards the warm, very warm, and bassy side of things, but still very smooth and enjoyable.
 
Starting from the low frequencies, they're obviously dependant on the nozzle choice. With the 'bass' ones, the bass is very prominent and dominant, quite strong and full-bodied. Quantity wise it is not far from being classified as a bass-cannon with an unforgiving impact. Fortunately, it manages to keep a more than acceptable level of control and doesn't really lack in detail for the asking price. Sub-bass is quite good, actually; reaching the lowest freq. without much effort with a very enjoyable rumble and speed.
 
Switching to the other nozzles is like almost turning a 'bass gain' switch off. The enormous quantities turn into a just north neutral in comparison; but still present nonetheless. The extension remains unaffected, but it's a much thinner and tighter bass, leading to a more balanced overall sound. That said, the whole fun factor is also missing and might be found even boring for some.
 
Despite the bass results from each nozzle, both midrange and treble remain pretty much unchanged. Yes, there are the obvious effects of the strong bass response, but the positioning and detail differences are less than what would be expected.
With the bass nozzle there's some bass bleed and general warmer tonality from lower to upper mids, while cleaner and a bit thinner and less veiled than with the other nozzles.
The midrange itself is somehow recessed and lacks a bit of presence. Detail and separation are rather good; nothing outstanding, though. Where the ED9 mids' real strength lays is in its musicality factor as it's more focused in presenting a very enjoyable and catching sense of warmth and detail.
Vocals are a bit distant but are sweet and full in body for a bassy earphone. Not my first choice for vocals centered genres, but would take the ED9 over something like the Xiaomi Piston 2 anytime without a second thought.
 
Treble is very smooth, a bit laid back with just a bit more authority than the midrange, but still kept in the safe zone. It will still give enough energy when really called, though. Upper extension is average, nice for the overall signature. Sibilance is not perceived at moderate volumes, unlike the Piston 2, and it's less grainy at lower highs than a Fidue A31s, but is also less resolving than both.
 
Stage is wide and deeper than average, but height is not enough to give a whole 3D effect. With the bass nozzles, the ED9 still sounds much bigger than the A31s or the Penon IEM, even without applying extra EQ.
 
 

 
 
 
Value:
 
The KZ ED9 is a very strong contender and very well valued for an IEM that just goes under $20. QC aside, the sound is very well tuned and very fun for the warm and bassy signature. Bass is quite addicting, a bit tiring at times, but well meant for bassheads in a tight budget. Not much to add here, simply a new addition to the 'best value' list.

Intro

 
One of the myriad of IEMs from the brand I most love to hate, the KZ ED9 offers an otherwise excellent budget package were it not for its manufacturer’s poor (if not outright lack of) quality control.
 
Before I begin I would like to thank George at Gearbest.com for providing the review sample of the Xiaomi Pistons 3.0 shown in this review. Please note that I am neither affiliated with Gearbest or any of its staff, nor am I being paid for writing this review. Unless otherwise specified, everything you see written in this review are my own honest opinion, so please take that with a grain of salt. All photos you see in this review are also my own unless otherwise specified. Thanks!
 
Knowledge Zenith, otherwise known as KZ, is as the title says – an enigma. That’s because we don’t really have that much information about them, and also because they’ve never bothered to release any of that. All we know is that they’re a Chinese manufacturer that makes a crap ton of ultra-cheap IEMs that they sell through online marketplaces like Aliexpress. That, and they have a massive cult following on Head-Fi that practically worship the brand with every post they make on the Asian brand thread or their official appreciation thread.
 
But I’m gonna get straight to the point. I don’t like KZ. I’m not gonna lie about that. I don’t like their lack of presence as a company. I don’t like their lack of ways to contact them. But I couldn’t ignore the cultish hype. It had me curious as to if they really were worth the continuously-spreading hype. And just a few weeks ago, the opportunity presented itself. And so here I am, reviewing one of the many IEMs from the brand I love to hate. Will they stand up to my expectations? Find out after the jump.
 

== Aesthetics ==

[size=20.007px]

​

[/size]

[size=20.007px]Packaging, Accessories[/size]

The ED9 comes in a plastic shield-shaped case devoid of marketing buzzwords and text, save for a list of specifications on the back of the case. It’s no Pistons 3.0, but at least it isn’t a shameless cardboard box. Inside is the ED9 itself, along with its surprising accessories package of three extra eartips and – get this – a pair of extra tuning filters.
 
 

Design, Build, Microphonics

Yes, tuning filters. I know, I couldn’t believe it myself. You really don’t get to see tuning filters – a feature more commonly found in IEMs priced $100 or above – in an IEM priced below 20 dollars. There is nothing on the package that explains what either of them is, but from here on out I’ll just call them the bass filter and the balanced filter. Build-wise, they don’t disappoint either, with rather weighty full metal housings and a surprisingly robust cable. The strain reliefs are built pretty well, although I feel the diminutive Y-split might become a point of failure for the IEMs in the future. As much as I hate to admit it, I’ll say I’m impressed at how much KZ is able to pack into this sub-$20 package.
 
But no audio gear is without its faults, and the ED9 does have its fair share of failures, mostly in the build. Once you go past the first glances, full metal housings don’t really matter anymore when the drivers themselves have a channel imbalance issue straight out of the box. The robust cable doesn’t seem as much of a good thing anymore when it’s practically a partially-uncoiled spring that’s almost impossible to completely straighten out. And worse yet, the audio started to cut out the very first time I plugged it in. (I’m not exaggerating anything – that really did happen the first time I took it out.) But let’s face it – KZ is your typical Chinese manufacturer of cheap products. Knowing this, there’s really no surprise that they have little (if any) quality standards when it comes to mass-producing their products. But if it’s this praised throughout the budget Head-Fi community, this is an issue that becomes all the more important.
 
 

Fit, Comfort, Isolation

The ED9 actually doesn’t fit too badly, staying snug and secure in my ears whether you wear it straight down or loop the cable around the ear (that is, if you can – the cable is incredibly stubborn and literally jumps out of my ears when I try to loop it around the back). However, the ED9 seems to have a sealing or damping issue, as the IEMs do not isolate equally (one side isolates less than the other). I don’t know how exactly this happened, but it has already been like this straight out of the box, so there’s not much else to blame other than poor quality control on KZ’s part. Again.
 

== Sound ==

Specs

 
 
 

Equipment, Burn-in

The source equipment used in this review is a fifth-generation iPod Touch and an iPad 3 directly running the KZ ED9, and a PC running iTunes 12 and Foobar2k powering the Jive through a Schiit Fulla DAC/Amp. The EQ apps used in their respective test is TuneShell on iOS and Electri-Q on the PC. The eartips used on the S3 are the included medium size eartips. The list of the test tracks I listen to while reviewing the Jive can be found here, although I will include links to specific songs in the review for a more direct point of reference.
 
The ED9 was burned-in for around 50 hours prior to writing this review. I noted no changes over this period, so I doubt there would be any more over time. In any case, let’s talk about how they sound.
 

Sound Quality

 
Bass Filter:
The ED9’s sound is honestly really hard for me to assess as the channel imbalance is practically splitting the IEM into two different sound signatures, each channel having its own twist on the sound. And I’ll be honest, I literally have no idea which is supposedly the “correct” sound of the ED9. The right channel is just a bass monster, with massive bass whatever you listen to. Its extension and sub-bass presence is phenomenal, easily taking the “Most Sub-Bass in an IEM Award” in my entire collection. It’s so massive that it tends to overwhelm the rest of the signature with all its slightly-distorted glory (Daft Punk – Motherboard). It’s so massive that I can practically feel the bass in Condukta’s Virtual Oasis. But the strange thing is, they manage to fall back and make way for the midrange when the song doesn’t explicitly have a heavy low-end (Yiruma – Fairy Tale). Its soundstage is also pretty good, with an airy space that reminds me of the Pistons 3.0.
 
The left channel, however, has a much more subdued low-end, sounding quite like the Pistons 3.0. The bass doesn’t overwhelm at all, instead sounding very controlled and refined. Again, I really have no idea which is supposed to be the “correct” sound here, but as the right channel seems to actually seal properly, I’m pretty sure the bass monster should be how the bass filter sounds.
 
 
 
Balanced Filter:
The balanced filters, in my opinion, really bring out the “true” sound of the ED9. The reason why I call it its “true” sound is because the balanced filters, well, don’t have any actual filters – it’s little more than a brass tube to hold the eartips. (In contrast, the bass filters have a black mesh that dampens a treble spike as seen in the image to the right.) The ED9 sans damping filter is more bass-light, bringing out more clarity and focus to the midrange and treble. The bass is still there, but it’s taken a few steps back, really bringing out the rest of the music to life. Guitars sound great (Sungha Jung – Coming Home). Pianos sound great (Yiruma – Indigo). Pretty much everything sounds great (Daft Punk – Give Life Back to Music). Can’t really say much more than that.
 

Summary:
Substandard quality control aside, I’ll admit, the ED9 sounds pretty great (how many times have I said that already?). It doesn’t have the straight-up versatility of, say, the Pistons 3.0, but its two pairs of filters do an equally effective job providing two different flavours of a similarly refined sound. So yeah, I’m gonna say it – the ED9 sounds pretty darn good.
 
 

Other Media

Okay, now I have a really hard time gauging how well the ED9 does here. Simply put, the channel imbalance really messes up the soundstage enough that I simply can’t use this for gaming properly. Audio cues coming from the left are rather distant and hard to pick out. Movies have the same problem. So no, I cannot give a proper rating of the ED9 in this section in its current condition.
 
 

Amp & EQ Response

The KZ ED9 was designed from the outset to work with phones and similarly weak sources, so one will have no trouble using it with your phones or iPods or whatever audio device you might have. Pairing it with the Fulla, I didn’t really notice any major differences sound-wise, beyond them sounding cleaner out of the Fulla’s improved DAC chip. Now, about EQ’ing the ED9…I really don’t see any reason why one would bother to tweak the sound through software when you’ve got an excellent hardware “EQ” from the get-go. So I guess I’ll leave it at that – there really isn’t much more to say at this point.
 
 

Value

The KZ ED9 can be bought from the official KZ store in Aliexpress, or a bunch of other sellers such as Gearbest for under $20. I would say the KZ ED9 offers incredible value at its price point, with its great build, great package, and innovative tuning filter system that really pinches the profit margins. But as much as I’d like to gush about its merits, all of it is shrouded by the fact that it came in partially broken. Is it really worth getting? To be honest, I can’t really bring myself to say yes, despite all the positives.
 
 

Comparison

Versus MEE Audio M9 Classic ($10):
The MEE Audio (formerly MEElectronics) M9 Classic was an impressive budget IEM, offering an unprecedented level of quality across the board at the rock-bottom price of ten dollars. From a sound standpoint, the ED9 easily blows the M9 out of the water with its refinement, its more balanced sound, and its neat tuning filter features. But when you consider the rest – the rest being the ED9’s iffy QC – the M9 ends up standing out as the winner in this face-off.
 
Versus Pistons 3.0 ($16):
I don’t think there’s anything to say here that I haven’t already said throughout the review. In the end, pretty much everything else beats out the ED9 by the fact that it’s not half broken. If, however, you manage to not get a dud pair, the ED9 will give you a brighter, more forward, and more aggressive sound compared to the passive-sounding Pistons 3.0.

 

== Conclusion ==

 
Earlier in this review I called KZ an enigma. But having studied and reviewed their ED9 I can say I have KZ all figured out. KZ is a manufacturer that designs very promising earphones that look to be worth it for the price, but their apparently horrible quality control leaves me still wondering why they have such a massive cult following – a cult following that bothers to spend over $100 dollars on 10 pairs of IEMs instead of two or three actually well-made pairs. They seem to not care about anything beyond designing the IEMs and stuffing them with neat features and an otherwise excellent sound. Beyond that, no, I don’t think they seem to care about actually making their products properly and consistently.
 
Whatever the case, as much as I want to like the ED9, I cannot recommend them under these circumstances. I know my complaints will fall on deaf – or rather, non-existent and foreign – ears, but KZ, straighten up your production process.
 
 

Suggestions for Improvement

FIX THE QUALITY CONTROL. I don’t think I’ve pressed a point any harder than that.
 

Shout-Outs, Gallery

I would like to again thank George at Gearbest.com for providing the sample of the KZ ED9 you see in this review. You could check out the rest of the images I took during the shoot here (link unavailable), and you could check out some more of my reviews here.
                                                                                                                               
This has been thatBeatsguy of DB Headphones; thanks for reading!
 

Changelog

The KZ-ED9 is one of the best in-ear phones i ever heard. Tried a lot and spend a lot on very expensives ie earphones.
This one is my favorite, very detailed sound! Use it with the Ibasso Dx90 and the FiiO E12A, love it! 

FIRST OF ALL I WOULD LIKE TO THANK HIFINAGE.COM FOR SENDING ME THE EARPHONE WITHIN 3 DAYS.....
         I AM ACTUALLY WRITING THE REVIEW AFTER NEARLY 2 WEEKS OF LISTENING AND TWEAKING IN ALL SPECTRUM OF THE SOUNDS WITH DIFFERENT SOURCES ......
  ONE THING IS FOR SURE,THIS PARTICULAR EARPHONE IS VERY SOURCE SPECIFIC AND ALSO QUALITY OF THE FILE SPECIFIC......
    SO WITHOUT WASTING TOO MUCH OF LINES ,LETS GET DOWN TO THE IN DEPTH ANALYSIS OF THIS IEM....
 
IEM WITH BRASS TUNING NOZZLE-
 
1.PACKAGING- CAME INA VERY LITTLE BOX....3 PAIRS OF EAR TIPS,TWO SEPARATE TUNNING NOZZLES,A GOLD ONE AND A BRASS ONE
2.BUILD QUALITY(4.5/5)-GREAT CABLE,AND METALLIC EARPIECE,AT THIS PRICE ITS NEARLY UNBELIEVABLE THAT THE COMPANY HAS REALLY THOUGHT ABOUT THE BUILD QUALITY.THE EARTIP NOZZLES ARE THOUGH PREETY HEAVY FOR THE EARS...AT FIRST I THOUGHT THAT I WILL DEFINITELY HAVE PROBLEMS WITH THEM EARING ON,BUT THAT IS NOT AN ISSUE SERIOUSLY.U WILL GET USED TO IT..
3.ISOLATION(3.5/5)-GOOD ISOLATION,AT MORE THAN AVERAGE VOLUME WITH COWON J3 THE AMBIENT SURROUNDING NOISE IN AN OPEN BUSY STREET CAME DOWN TO 70%.
4.SOUND QUALITY(4/5)-AH THE MOST IMPORTANT PART.......
            WHEN I FIRST GOT THIS EARPHONE AND PLUGGED IT TO MY COWON J3 I WAS REALLY DEPRESSED AND SHOCKED....I THOUGHT TO MYSELF WHAT ON EARTH IEM I HAVE BOUGHT....THE PREVIOUS DAY I WAS LISTENING TO HIFIMAN RE ZERO....AND TRUST ME MY FIRST IMPRESSION ABOUT THE IEM WAS DAMN BAD....BUT THEN I THOUGHT TO GIVE THIS IEM A GOOD DEAL OF TIME TO SETTLE IN...I DONT BELIEVE IN TOO MUCH BURNING AN IEM IN A WAY IT SHOULD BE...I JUST KEEP LISTENING TO THEM FOR HOURS AND HOURS UNTILL IT SETTLES DOWN.....
 
FIRST IMPRESSION-OMG TOO MUCH SIBILANCE,BAD TREBLE REFINEMENT,A HISSING SOUND EVERYWHERE...LITERALLY I WAS FRUSTRATED..
AT THE END OF THE FIRST WEEK--THE EARPHONE STARTED SETTLING DOWN...SIBILANCE WAS NOT THAT MUCH,IMAGING WAS GETTING BETTER AND I CROSSED MY FINGERS HOPING FOR THE BEST......
 
AT THE END OF 2ND WEEK-ITS LIKE THE EARPHONE HAS COMPLETELY EVOLVED INTO A NEW AVATAR AFTER TEWKING A LITTLE BIT OF EQ ON MY COWON J3...
 
BASS-APT,VERY GOOD EXTENSION,GOOD AND POIGNANT SUB BASS,NON OVERWHELMING,NOAT ALL BASS SHY,BASS RESOLUTION-MODERATELY FAST,PRESENCE ACROSS SPECTRUM-GOOD.
 
MIDS-FULL FRONT FACED,HAD TO TWEAK A LITTLE TO MAKE IT SLIGHTLY LAID BACK,VOCALS PRISTINELY CLEAR,SWEET AND BRILLIANT IMAGING WITH AMPLE SEPARATION FROM THE REST OF THE SPECTRUM.CLARITY-SURPRISINGLY VERY GOOD.A DEFINITE UPPER MID HUMP THOUGH STILL INTERFERING WITH THE TREBLE PRESENTATION
 
HIGHS-LACKS REFINEMENT BUT EXTENSION IS QUITE GOOD,RESOLVES PREETY QUICKLY BUT DEFINITELY SPARKLING.
 
5.SOUND IMAGING(3.5/5):WONDERFUL...SIMPLY NEVER EXPECTED THIS FROM THIS IEM..LOVING IT REALLY...THOUGH NOT QUITE IN THE LEAGUE OF VSONICS ,FIDUE,HIFIMAN .....BUT WHO IS COMPARING...ITS ACTUALY 1/10TH THE PRICE OF THEM...
 
6.SOUNDSTAGE(4.3/5)-OMG...PERHAPS THE STRONGEST POINT OF THIS IEM...AIRY,FANTASTIC DEPTH AND WIDTH.....SIMPLY FEELS LIKE BEING IN A SMALL THEATRE ...ITS REALLY THE MOST AMAZING FEATURE OF THIS IEM TRUST ME...
 
7.VALUE FOR MONEY(10/10)- WITH AN AMAZING BUILD QUALITY ,A VERY GOOD NEUTRAL SQ WITH AN EXCEPTIONAL SOUNDSTAGE AND GOOD CLARITY AND IMAGIING PERHAPS THIS IS THE BEST IEM  I HAVE LISTENED TO UNDER 1000INR OR NEARLY15$.HIS IEM IS HIGHLY RECOMMENDED FOR THOSE PEOPLE WHO LIKES A NEUTRAL SQ ,REVEALING SOUNDSTAGE AND JUST AN APT BASS.AT THIS PRICE POINT ITS SIMPLY UNBEATABLE....
 
8.OVERALL-FOR ALL THOSE PPL WHO HAS A CONSTRAINT OF SPENDING LAVISHLY...THIS IEM COMES HIGHLY RECOMMENDED.....PHILPS SHE3590(WHICH WAS MY RECOMENDATION PREVIOUSLY AT A LITTLE LESS PRICE)PALES AWAY IN FRONT OF IT.SO DOES BRAINWAVZ M2,M3 AND SOUNDMAGIC PL 30,PL50,E10....REALLY A GREAT EARPHONE FOR THE PRICE!!!
 
JUST A QUICK NOTE-AVOID BAD SOURCE AND QUALITY PLAYING FILES AS IT IS A PREETY REVEALING EARPHONE,BRINGS OUT THE FLAWS OF RECORDING GREATLY....
 
HAPPY BUYING!!!!CHEERS!!!!!