KZ SA08 Balanced Armature 4BA AAC TWS

General Information




Professional 4BA HiFi TWS
As a professional HiFi earphone manufacturer, KZ integrates 4 balanced armatures for SA08. With 22955BA for bass, 29689BA for mids and 31736BA for high frequency, you can enjoy a loose and natural bass with wide frequency response, transparent and full instrumental music and vocals, high resolution and rich details. It will restore the sound as original

Physical Passive Noise Reduction Technology
KZ SA08 adopts the latest technique to reduce external noise interference. The outer curve of the cavity is designed for the structure of the human body fits closely with the auricle. After being worn correctly, it can effectively reduce the interference of external environmental noise and enjoy music quietly

Bluetooth 5.0 AAC Decoding
Equipped with the new Bluetooth 5.0 chipset, the transmission is greatly improved compared with the previous version. It brings more stable connection and supporting high-quality music transmission. AAC coding format reduces the hearing while the volume is more compact. It achieves a good balance between sound quality and transmission efficiency

Single Use or Both? As You Wish
Both earbuds of KZ SA08 can be used independently. It’s easy to switch between single and double ears. Most TWS distinguishes in the use of the main and sub-headset. It usually only support the independent use of the main headset. However, SA08 is not like the rest. The left and the right earbuds can be used separately and even for normal calls

High Performance Mode&Auto Pairing
For SA08, you can click 3 times to turn on high performance mode. The signal is stable and continuous and no delay in the sound effect of mobile game. The quick synchronization is amazingly pleasant. It also improves battery life and lower power consumption. Besides, the auto-pairing function avoids complicated operations, simply connect once and save the rest


Driver Configurations:
-22955 balanced armature*1 for bass -29689 balanced armature*1 for mids -31736 balanced armature unit combination*1 for highs
Charging case weight: 44g
Single earphone weight: 5.7g
Earphone battery capacity: 30mA(single ear)
Charging case battery capacity: 400mA
Charging case dimension: 32*61*61 mm
Earphone dimension: 19*24*27mm
Earphone battery capacity: 30mA(single ear)
Frequency response: 20-40kHz
Sensitivity: 102dB

Latest reviews


100+ Head-Fier
Great sounding lego bricks that fail in the practicalities
Pros: All-round audio quality, sound stage elasticity, acceptable mic
Cons: Form factor, battery life, fit, no IPX rating


How I review:

Sound Quality

Subjective and objective assessments. I listen to a few key tracks, some FLAC, some bad quality mp3's, streaming services, audio books and tracks I know have been so badly produced they will probably clip the top or the bottom end. Usually I listen to one album in particular on FLAC as a reference class, and also Andre Rieu's Bolero, which again I also know inside out and has sufficient orchestral content for me to discern separation and sound stage.

I then test a few key variables such as FR and Spectral Flatness using an acoustic mic setup and a few different programs on my PC running Windows 10, which are not perfect but the results give me something to reference against. I may elaborate further with additional checks which are pointed out where applicable. I usually also check what's going on with the codecs using Bluetooth Tweaker.

I test on a Poco X3, Apple Iphone 8 and Windows. Mostly I'm reviewing bluetooth headphones so no need for any complexities. If there is an app, I'll test firstly how intuitive it is, and secondly review the EQ settings. If none are available, I'll use Wavelet and customise the EQ to try and get my signature sound, and also test how they perform with certain presets.

I do this just for confirmation of what I'm hearing. I'm not Scarbir, I'm not The Sound Guys. I have a demanding day job, study, and have three kids, so no long essays in these reviews.

I test using:

Stock tips
Spinfit Silicones
Tronsmart Apollo Bold tips (which seem to fit me perfectly)

INAIRS foam tips (where appropriate)
ikko i-planet foam tips (where appropriate)

Microphone Quality

I conduct a few different tests, as follows:

Indoor, static, silence
Indoor, static, ambient noise 40-60 dB-A
Indoor, static, high frequency ambient noise
Indoor, static, low frequency ambient noise

All of the above but moving
All of the above moving away from the receiver

Outdoor, static, ambient noise 40-80db
Outdoor, moving, ambient noise 40-80db
Outdoor, under a nearby railway bridge where lorries pass through
Outdoor, in the wind and rain when possible

On Zoom or Microsoft Teams
On IOS (Iphone 8)
On Android (POCO X3)
On Windows 10

All are recorded for 1-3 minutes for future comparisons. I look for voice clarity, voice clarity among noise and glitches, suppression, naturalness and consistency.

Where possible, I ask my kids to also test to see what sounds the CvC or MEMS compression method is really trying to stifle, and whether it succeeds

ANC (where applicable)

As per the call quality tests, I usually test the ANC at the same time, looking for low and high frequency performance. I simulate white noise, use a fan, then take them down to a railway bridge. PNI is also attributed and scored where applicable. Ambient mode is also tested, and particularly important for earbuds designed for exercise.

I suffer from vertigo, jawache and migraines when the ANC is really strong, so I will highlight this where applicable. To date no earbuds have induced this from the ANC alone and the last headphones to do so were the Sony WH-1000XM3.


I use earbuds in four activities - calls, exercise, commute and relaxing. All three are taken into consideration to try to find the use-case, as finding the perfect earbud is, lets face it, probably never going to happen.

For fitness I am looking for the ability to stay in the ear, for commuter / home office use they would need good all-day comfort, and for relaxing they ideally need to pass the pillow test and stay in overnight, and at the very least provide comfort for prolonged use.


I find most perform almost identically, but do the usual walk test, especially around congested 2,4ghz wifi areas, putting as many barriers as I can in the way to . I leave a router on 40MHz just in case it messes with it, why the hell not?! When possible I would take them out and see how they perform in the pocket.

Other Features

Wireless charging, long battery life, a feature rich app, intuitive controls, good codec support, dual-mode and multiple latency modes are amongst the attributes that get the high scores.

Model: KZ SA08
Price: $60
Distributor: Aliexpress
Link: Buy Here
Vendor Website: Here

Manufacturer Blurb:
  • Brand Name: Linsoul / KZ
  • Model: SA08
  • With Microphone: Yes
  • Connectors: Type C
  • Sensitivity: 102dB
  • Frequency Response Range: 20-40000Hz
  • Bluetooth Version: Bluetooth 5.0
  • Audio Decode: AAC, SBC
  • Bluetooth Profile: AVRCP/HFP/HSP/A2DP
  • Bluetooth Chipset: Not known
  • Maximum Working Range: 10m(no obstacle)
  • Earbud Dimension(L*W*H): 19*25*27mm
  • Waterproof: IPX4 (stated)
  • Dual/Single Modes: Yes
  • Earbud Weight: 12g (stated 5.7g each)
  • Case Weight: 44g (stated 44g)
  • Driver: 22955 balanced armature*1 for bass -29689 balanced armature*1 for mids -31736 balanced armature unit combination*1 for highs
  • Microphone: Yes
  • Playtime: 2-3 hours (stated 4 hours)
  • With Case: 12 hours

1 x pair wireless earbuds
1 x battery charging case
1 x Type-C USB charging cables
1 x User manual, quick guide, warranty card

Real Life Experience

Firstly, let me introduce my excitement at this release. KZ are known in the IEM market for, whilst somewhat inconsistent, cost-effective buds with an incoherent naming convention and seemingly no target sound signature. That said, they are a fun vendor to experiment with in order to try to find the sound that suits you best - and remember this is always transient anyway (otherwise we wouldn't have EQ's!)

The prospect of 8 balanced armatures in TWS is almost unheard of. Well, it is unheard of other than this model! Whilst this may not be anything spectacular in the IEM world, for TWS my first thought was 'what are they going to trade off', because eeking out this level of power or performance from a bluetooth chip is going to be interesting - even if they have come on leaps and bounds lately.

KZ's foray in the TWS world has been mixed to say the least. As good as the T1 sounded, they suffered with dropouts and poor battery life. Subsequent releases didn't improve matters either.

The SA08 delivered exactly what I was expecting - and probably what everyone else is too, but without giving too much away, on to the review:

The Unboxing - 6/10

After waiting 2 months for these to arrive, it was great to see these finally land on my doorstep. The construction of the case is on the premium side although very minimalist, almost Bauhaus! The Tronsmart Apollo Bold wow factor, taking you on a journey through manufacturing has been ignored in favour of durability - it's more substantial than your TaoTronics/Mpow/Soundpeats budget boxes - and it needed to be given the battering it took on its epic journey through Europe (the joys of buying through Aliexpress)


The excitement is quickly quelled when you realise you need to be Edward Scissorhands to get it open, because it sits completely flush. And unlike the iPhone, who adopt a similar style, teasing the base and the lid apart is not an option. Brute force and warranty voiding are the order of the day.


With my finger nails already bitten to the wick due to their prolonged AWOL period in Liege, you can imagine the state of them by the time I finally prized it apart.


The contents are offer no surprises - standard fare for KZ - everything you would expect, USB cable, reasonable quality transparent silicone tips, and all documentation stored in a small envelope, mostly in Chinese.

The Case - 6/10

The case is becoming seemingly more and more important as earbuds have evolved. I find myself moving the case around in my palms and scrutinizing stuff like the hinge strength and portability in far more detail than previously. I think it comes down to trying to find faults as earbuds have improved dramatically in the last 12 months.

Having seen my artsy opening pic you'll probably recognise the case. We've seen this 'puck' design somewhere before haven't we?! I don't remember who has the bragging rights if you could call it that to the design, but it's the same shape as previous KZ releases, and I'm pretty sure they used MIFO for the S1D, and identical to the Zen 233621, Cleer Ally Plus and Tronsmart Apollo Bold. And it gets the same score as they did, because it suffers the same issues.


They've replaced the hinge with a smaller, but noticeably stiffer component, although whether this is down to the period of time I've had the Apollo Bold, I don't know.

The etching of the KZ logo is very shallow compared to the Tronsmart, not that that makes the slightest difference to anyone, but is an observation that I'll note here anyway. You can tell I'm struggling here can't you :D


The dimensions are outlined below:


This makes them one of the larger TWS cases around, and is a 'jacket pocket' job - i.e. you wouldn't want it weighing down your trousers. The case weighs in at around 56g - a touch on the heavy side.

One of the big problems with the Apollo Bold case was the recess on the ceiling of the lid being too deep. This meant if the case turned upside down with enough vigour to break the magnetic hold, it could cause battery charging woes - i.e. you take them out and they're dead.


Getting the earbuds in and out of the case is also an ordeal. Getting them back in being the lowlight - they're a nightmare. The notch you can see in between the two buds lights up different colours depending on how much charge it has - IIRC it's green for 75%-100%, amber for 25%-75% and red for below, but I can't get the box back open to check!!

The case is 400ma and charges the buds a further three times - it is connected by USB-C, doesn't support quick charge or Qi wireless charging.

The Ergonomics - 6/10

I guess there's two parts to this - how they look and how they feel.


The profile on the outside is fine - it's the teardrop shape they use with other IEM's and is popular with the likes of MIFO and TFZ. The lights change blue or red depending on whether they are paired, are pairing, etc.

The problem for me is that whilst they have tried to get a custom fit against your concha, whilst they achieve this, in order to squeeze in all those balanced armature drivers they end up looking, and feeling, like you've got lego in your ears.


We thought the Apollo Bold were beasts, but these are in another league.


The problem is exacerbated further, as whilst they aren't excessively heavy, they are somewhat lopsided. Due to the weight displacement being so disproportionate, they can come loose very easily, even with foam tips (as pictured above). Adjustments galore! This can ruin the sound, as even a micro adjustment can screw with the deliver, and be pretty annoying at the best of times.

However the drivers are round and the neck is long, so depending on the proportions of your inner and outer ear, this could allow deeper insertion, which would improve the already very decent isolation they offer even when balanced tentatively like a learner swimmer taking their first dive off the top diving board, as they were in my case!


Clearly some thought has gone into the ergonomics, although the alloy battery connectors still touch the skin - not one for those with allergies.


Everything about the finish is what sets experienced manufacturers like KZ apart. Despite their relatively young life - they're around 5-6 years old - this is not their first rodeo, and it shows - the materials used are high quality and well finished, although you can't help feeling this doesn't help with the weight displacement issue.


Without the ridged are that you can see beyond the L to the outer edge, these would actually be really nice fitting - and that, my friends is the first trade off.

There is no waterproof rating evidenced anywhere other than a few aliexpress sites stating IPX4 -

Audio Quality - 10/10 (for the price paid), 9/10 (raw score)

Well well well. KZ have somehow managed to balanced technicalities and clarity with warmth and depth. Honestly my mind was blown - I mean it's not in the league of IEM's, and it certainly plays fast and loose with the idea of being balanced, but everything sounds magnificent.

The all-round sound is reminiscent of my favourite budget IEM's - the Blon BL-01 - the bass is fast and pronounced but levels off perfectly with a rich but not overbearing subbass, I've seen some reviews saying low mids are recessed, but that certainly wasn't the case with any of the tracks I tested them with. In fact - I would say the opposite, it's the high mids that can be a touch harsh. The treble is far brighter than the ASF and for prolonged use you may want to EQ it a shade as the sibilance we come to expect with TWS is discernible. Vocals and instruments separate extraordinarily well for TWS,
I have seen some reports of white noise, and whilst I expected this given the sensitivity of balanced armatures, I can't hear it. That could well be my hearing though! I also read some criticism of them sounding tinny - I couldn't disagree more, they are quite the opposite in fact. I did notice that they are very dependent on positioning though - get that right and the bass shines through.

I was so blown away I tested them with tracks I produced years ago, and sure enough they sounded pretty close to my reference speakers. Very very impressed. They use AAC on all devices.

A final word for the soundstage - wow. It can effortlessly gravitate between intimate and airy, just as quality earbuds should.

The 9/10 score is for TWS. Remember, the results on TWS are not comparable to wired multi-driver IEM's, and this is clearly evident if you switch straight after.

Call Quality - Indoors - 7/10, Outdoors - 6/10

Far better than I expected and better than previous attempts from KZ. Not unusable and clearly some effort has gone into isolation, as they performed fine outdoors. Cars are audible but muffled. Sadly you can sound a little robotic, but clarity is retained, so a job well done.

Connectivity, Controls and Other Features - 6/10


Controls are awkward. The flat outer plate is not sensitive - you have to get them in the right spot, and often if you try and switch between high performance mode and normal, you will end up shutting the earbuds down or removing the pairing, which is most annoying. Unfortunately no volume controls :frowning2:

When you do make contact, they're responsive, and there's no 'lag'. Connectivity spoils them though - yet again the left and right earbud drop out periodically. This can ruin relaxing and listening to your favourite jams in full flow.


KZ don't advertise anything other than the low latency / high performance mode other than the Balanced Armature drivers. Unsurprising really, as that's about all they have to offer. You can use them in single or dual mode though.

Latency is OK-ish...even in low latency mode it definitely isn't close to lip-syc and Bluetooth Tweaker didn't give me any clues either.

As mentioned earlier, no wireless charging, no app, no nothing really - just very good sound.

Battery Life - 6/10

As expected battery life suffers. Even at 60% volume - and these are loud - I have invariably achieved between 2 hours 15 minutes and 3 hours 10 minutes on a single charge. That could mean 12 hours, it could mean closer to 9 - not enough for some.

Final Comments

The intro kinda summed it up. They sound great, without question - but the practicalities are hurdles that KZ still haven't overcome. Without good battery life, well-distributed ergonomics and strong connectivity, these offer one use-case - at home - when most of their customer base has amps and IEM's anyway.

The cynic in me thought the 4BA per bud would be a gimmick. It clearly isn't. They have managed to add detail and clarity to a punchy, v-shaped sound signature that will wow consumers but leave audiophiles wondering what the fuss is about - I'm somewhere in the middle, I love that they've managed to get this sound profile into a TWS, but hopefully this is the springboard to resolving the basics.

At £45ish they are reasonable value for money so temper expectations accordingly - these are evolution, not revolution.

Price Weighted Score: 80%

Raw Score: 77%
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If they had 5 hours or so battery life, I'd get a pair. I like my kz S1 but the battery life is too short. They need to squeeze 50mah cells into them.
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Reactions: blorg
That battery life is a dealbreaker in 2021, it's ridiculously low. I really like KZ 's wired IEMs but they don't seem able to actually integrate it into a well functioning TWS package. I tried the S1 off the back of how happy I was with all my other KZ IEMs but had to send them back due to constant BT dropouts. Battery wasn't great there either, and the case and IEMs were also a bit large and unwieldy and the fit off. Every other KZ IEM I have fits really well. Hopefully they'll figure it out.
How well does it perform compared to Tronsmart?


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