KZ AZ09 Bluetooth 5.2 IPV5 Waterproof Noise Reduction Bluetooth Module Upgrade Cable Ear Hook for ZST/ZSTX/ZS10/AS06/AS10/BA10/ZSR/ES4(B pin)

After ordering 2 different sets of IEM BT cable adapters from KZ (TRN BT3S and KZ HD gray cable) and I picked up the AZ09 against some of the reviews and was pleasantly surprised that 1) finally my callers could hear me properly. 2) it connected very fast like the KZ HD but I could use just one ear if I wanted and 3) the case is slick, magnetically grabbing them into position and charging them on the go. The led indicator is helpful and these finally let me wear my glasses much easier than the other two which I had to constantly trap the wire underneath the legs so they wouldn’t fall off. The BT3S were not bad mic wise but its not BT5.2 and connection was so so. Cutting in and out with a snapping audio cut everytime was irritating and replacing iphone clicking sounds with these annoying loud beeps sucked. Latency was terrible as well, had to re-pair them quite a few times to get them to sync up again. The KZ HD set was a good one and I hesitated returning them but the one main flaw was the length and arrangement of the wire. If they update the BT3S with the guts of the KZHD and shorten the cables a bit they would have a winner. Alas whenever I would take off the left one it would drag the mic and buttons to the back of my neck and that SUCKED. As a listening set it sounded great. I might say maybe better than the AZ09 by a bit. Louder and cleaner. By 5-10% Overall I am very satisfied with these AZ09. Sounds close to wired sound and I have them paired with KZ ZAX Metals in black which sound fantastic on them. Little bit of noise floor but tolerable for a day to day device. But they win all around. Definitely recommend them.

I bought the AZ09 to pair up with my KZ ZAX and iPad Pro 11 (2nd Gen). The sounds was great, pairing was easy. After about 10 minutes the audio skipping started. Followed the standard instructions and removed the device, rebooted my iPad, re-paired and same thing happened. I than paired to my iPhone 11 and no audio skipping with a super stable connection. I than paired them to my iPad Pro 10.5 (1st Gen) and again no audio skipping, so I relegated the AZ09s to the closet never to be heard of again. However, I went on the internet to search out this issue on the iPad Pro 11 and it turns out that there is a bug with “hey Siri” enabled and audio skipping. Turned off “hey Siri” and problem solved. I am now finally enjoying the AZ09s full potential. They do produce a slightly warmer sound signature. Bass and mid-bass ranges will be slightly more pronounced, mids and highs still sound great paired with the KZ ZAX. You will also get a little bit of audio compression but the is the price of Bluetooth. There is a high performance mode that cuts the audio lag in half meant for gaming and works as advertised. Battery life is excellent with fast re-charge rate. If you are getting audio skip on you iOS device, disable “hey Siri” and try again!

I bought KZ ZS10 Pro's a while back, and have been loving them since, and decided to go ahead and try this bluetooth set for them. I figured at the price point, even if it didn't work right or was just unpleasant to use, I wouldn't even be that upset. That said, I absolutely love them, instead of meeting expectations, they blew them away, and I've been super happy with them in almost every way. Also sorry this is so long.... Small side note, the cons list is *not* longer, it's just more specific because I kind of had to nitpick a little bit, I genuinely don't have much bad to say about these personally, the star rating should speak for itself. TL;DR - If you want these for your pair of KZ IEMs, just get them. Do it. Pros - Sound quality - Obviously when paired with a set of IEMs that sounds good, I didn't notice any real quality degradation. My ZS10's sound just like I expect, and that's exactly what I wanted - Comfort - I wear these for 10 hour shifts at work, one ear at a time, swapping at lunch, and they haven't been uncomfortable yet - Battery Life - They will last well past 6 hours of continuous use, when I make my swap at lunch, I've been at around 40% life, and that's 5.75 hours into my shift - Connectivity - As of yet, I've not seen them even hesitate to connect to my phone, I open the case and I hear the little voice say "Connected", seamless and super fast - Build quality - While the case will be mentioned later, the bluetooth bits themselves are awesome, they're solid, the buttons are well placed, and I'm not nervous at all that they're going to fall apart or break on me - The Case's Function - The case genuinely belongs in both the pros and cons, it's here in the pros because it does have a USB C charger (that it comes with, a cable at least), it has never had an issue with actually holding the modules to charge, and it has a foam bit in it to hold the IEMs in their well safely. It's well thought out, and I think it does its job great - Buttons - There's physical buttons. You can't press them accidentally, you won't double tap if you didn't mean to, they *can* be pressed with just one finger, they're leaps and bounds above dealing with touch sensors. Yes it's technically a "moving part to break" but they seem robust and they're pleasantly tactile - Value - While these obviously aren't capable of producing sound by themselves, even including the price of these in conjunction with the ZS10 Pro's, I spent around $75, which puts them at about half the price of the (original) Galaxy Buds I'd been using, and I like them so much more in terms of comfort, sound quality, and the fact that there's no touch sensors - Call Quality - They are described to me as "7/10" and "about what should be expected from a good quality pair of true wireless earbuds", and I consider that beyond good enough for the price Cons - The Case's Build Quality - To be fair, I don't think it's *that* bad, and it seems sturdy enough, but the hinge is a little flimsy when open. It also is a little chunky, but considering the size of the modules+IEMs, that's not surprising(and not that bad) - Button function - While I like that there's no companion app, it's a little unfortunate that you can't change what the buttons do - For example, I'd like a double click on *either* side to do "Next Song", but double clicking the left side's button does "Previous" instead, which I almost never want. (This is a minor complaint for me though, I do have a smartwatch that I can use to control media anyway) - Where the IEMs connect - Again, this isn't a huge issue, but I did cut away a tiiiiny bit of the plastic around the connector that connects to the IEM, it doesn't quite fit around the IEM's connector, and feels like it should push all the way in, but there's like another 0.5-1mm of length on the contacts. It felt fine how it was, and I'm sure it would have been, it was holding just fine before I modified them, but I feel cutting away a tiny bit of that plastic surround made a bit of a better connection - If you have a smaller ear, or the original cable that comes with specifically the ZS10 Pro's(potentially others, I've only ever had these ZS10's ) doesn't fit you well, these bluetooth bits may not be the best fit. They fit me *perfectly*, but the original ZS10 cable does as well, so that may be something to consider if you know your ears are smaller than average - ANC/Ambient Modes - I don't think there's any ANC or Ambient modes, or if there are I haven't figured out how to get them active. This is *not* a con to me, those aren't features I want, but I figured it's worth a mention

I'm just trying this out now, straight from the packaging. It comes fully charged. I used a pair of cheap ZST in ears I got also off Amazon a few years ago to test them. Pairing and setup was as easy as it could possibly be! So the Bluetooth tech is good tech inside! The voice samples that tell you the device is on/paired/etc are REALLY poorly recorded, which gives you the impression that the audio quality won't be good. But that is not the case. But the actual audio quality is quite close to a cabled connection, the signal has enough drive to push out bass frequencies on the ZSTs I used. Frequency response seems to be pretty flat and true, with maybe a hump around the 1-1.5khz range but that might be the ZSTs. Triple tapping the earpiece will put the drivers into high performance mode which gives a small boost in volume. I'm going to use these in the gym today and I'll edit this review to provide the battery percentage. But so far, this is an incredible buy!!!

I would like to start my review saying I only have bought one pair of these and therefore I could have gotten a lemon. With that said there is some good and bad, so here's the Pros & Cons. Pros: Good sound quality - I used the KZ AS10s and these drove them well so no issues there. Fit - I like the fit, they do look like hearing aids tho, but style points aren't huge on my list. Can get a little uncomfortable after VERY long use sessions. Battery life - I get a few hours out of em, no complaints. Cons: The case - large, clunky, the LED is annoyingly bright if you charge overnight and it could use a non-slip coating. The earbuds constantly rattle around but this is because you can use any IEMs that are compatible so this is fine. The connection - Dear god this is the worst issue. They constantly connect from the case and discharge overnight. The left earbud constantly cuts off audio for 0 reason, 2 feet away from my phone which normally works 100% of the time. Usability - Only Play/Pause, I would appreciate more buttons or other button combos to control media. Overall: Again I do not know if I got a bad pair or what but the connection issues are so so so annoying. It makes using them a pain and I wish I could like them more. Good idea, good build quality but PLEASE FIX THE BLUETOOTH CONNECTION ISSUES!

I've been pretty stubborn when it comes to trying out wireless headphones and earbuds, constantly preferring to buy phones with headphone jacks and always sticking with wired because I really never saw the cable as that inconvenient. And I've pretty steadily using KZ ZSN Pro's for the past year and a half, being some of the best value I've gotten from headphones to date. So when I discovered that there was an official bluetooth accessory for it at a reasonable price, I had to try them out. Well I'll start with the good: The packaging and build quality - As with the ZSN Pros, the packaging and overall build is phenomenal for the price you pay. I've had worse presentation from earbuds costing 4x as much as these things, and just the general feel of the actual case in the hand is nice. It's obviously a bit bulky, but it'd be a bit much to ask for Airpod like footprint from something this cheap. The magnetic hinge is a bit slippery for my tastes but works perfectly fine. Also glad to see Type-C charging and an included cable (albeit a comically short one but points for including one at all). The look - I absolutely love how these things look. Integrating the original braided cable design from the ZSN Pros with the small bluetooth receivers. I appreciate them not going with the usual long flat cable design that so many cheaper wireless earbuds do and making them look even more expensive. The case itself also looks as premium as something far more expensive (even if it doesn't feel quite as nice as it looks). Sound quality - This shouldn't be much surprise if you're familiar with the original IEMs, but they sound just as great when they work (not to bury the lede here). They sound maybe just a *tad* worse than if you use them wired, but it's such a minute difference I wouldn't notice if I wasn't looking for it. I've seen some people complain about increased static (something the original ZSN's struggled with), and it was maybe also a *tad* louder but if you're used to it on the wired version you'll be fine. And honestly, I didn't notice a difference really between the high performance and normal modes, although that might be down to my limited testing and not trying any lossless audio with them. The average to bad but inconsequential: Initial setup - I found it a bit clunky at first, because only one would pair at first (seemingly because there was supposed to be tape over the contacts keeping them from connecting without removal but one wasn't even int he correct spot) and it's not exactly intuitive if you haven't checked the manual beforehand, but it could definitely be worse. And chances are you won't be doing this much either way so whatever. The built in voice - There's a voice that comes on and tells you when a function has been done such as "disconnected" or "pairing". Normally this would hardly be worth talking about, but the AZ09's is so atrocious I can't help but mention it. It's rather inconsequential which is why I put it here, but they're using a text to speech thing very clearly not meant for English, as it manages to pronounce "disconnected" like "dis-cone-neck-tate" with a very odd accent. It's still usable, but it was an odd choice to not just use a voice designed for the language of whatever market they're releasing it in. And the bad: Staying connected - If there's one thing I can hope bluetooth headphones don't screw up, it's managing to stay connected to my phone while I'm listening to music. You know, the basic thing they're designed to do. But these don't manage to do that. For context, I decided to take these working out one day to test them out. My phone is no more than a foot or a foot and ahalf from my ears most of the time, sitting on a machine. I don't even end up moving my head much while using them period. But over the course of about and hour and a half, these were near unusable. I could not listen to a single piece of music without the left and right ears dropping out constantly, almost independently of each other. I switched to high performance mode hoping this would fix it, but found no respite from the godawful experience of using them. I kept hoping they would get better, but nothing changed over the course of my workout. In fact, I could swear they got even more flaky as time went on. They were at 100% battery as well, so I have zero reason to believe this was tied into my dropouts. I later tried them at home, literally sitting completely still at my desk and found the same exact experience as before. Overall, I just cannot recommend these when they can't even do something as simple as stay connected and transmit audio for more than 5 seconds without dropping out. I expected better from KZ, I really did, and I hope they can manage to release a new iteration that fixed this issue. But for now, I refunded my order and I'm sticking with my wired ZSN Pro's for the foreseeable future.

Very happy with these earbud adapters. They have awesome battery life and the sound quality seems to be equal to when I use my earbuds as a wired headset. I have now switched to using my ear buds with this adapter exclusively. I use these whenever I am not at home and I want to listen to music or an audiobook. Extremely happy with this purchase. The price is very reasonable and the performance has no problems. Only one minor silly criticism. It has some verbal cues when you connect, turn on, or turn off the earbuds, and they have terrible pronunciation from the narrator

So far so good. Set up and connection were clearly described and went off without a hitch. These are much lighter and looser fitting than my TRN BT20S. I've paired them with my KZ ZAX, and they sound amazing! Very pleased with this purchase so far, and for the asking price it's a no-brainer. UPDATE: Seemed to work fine at first, but after about a week of use they are constantly and frustratingly cutting out. These have become unreliable and ultimately unwearable. :( SECOND UPDATE: Seller offered to replace with a new version. So far connection is flawless and all is good!