Para su precio están súper buenos ! La calidad de sonido es excelente de hecho es una delicia escuchar música con ellos ! El material se siente súper bien y son cómodos !GraciasI gave these a 4 ONLY bc I’ve not used them yet in performance at church. I did use on my phone just to try them out and found them comfortable and sound quality good. However, I am not a professional and my opinion is my own.KZ-ZST XThe KZ-ZST X is a 2 way hybrid In-Ear Monitor with a 10mm dynamic driver for low frequencies and a balanced armature for high frequencies. The shells are made of sturdy plastic and are very light and all-day comfortable. The replacable silver cable is a step up from the brown cables of the original. Not bad! I installed red and white tips to tell left from right more easily.The original KZ-ZST was my introduction into affordable multi-driver iems and this is a huge step forward in design and sound quality. The original ZST had a very V-shaped sound with the mids turned down and the bass and treble boosted. It had good bass response but harsh treble. It was still a revelation for me at the time and sounded far better than anything anywhere near its price point.Things are much improved with the new ZST X. It still has excellent, powerful, bass, even more controlled than the original. The mids, while still recessed, are worlds more detailed and they are not as v-shaped as the originals. There is still a bit less low mids than neutral, but most will appreciate the open airy sound. A boost to the lower mids will thicken things up if desired. The highs are very detailed and mostly smooth without any nasty peaks. There is a much larger soundstage and more air up top. These sound really good! They even give a decent sense of depth which is uncommon among budget iems. There is much more detail and imaging is very good. These just sound more polished and grown up. Its amazing what less than $25 buys these days!I have purchased many IEMs from Yinyoo.... too many if you ask my wife! As always, they are great to deal with!Thank you for reading! If you buy them, you will be very happy!I can't believe these aren't way more popular the value is top and the price is perfect.I have extra pairs now the sound is almost a 5 star rating honestly, super crisp highs and good lows plus clear mids.The setup is just right.The size is perfect for my ears and you get different size bud gels.I really do sleep with them in every night.( Your mileage may vary.KZ ZSTX is what KZ calls in updated version of the ZST but really these IEMs are playing their own game. While the build and fit are identical, the ZTSX cable is SO much better than the ZST cable, and the sound has evolved enormously. The cable has the newer iteration of KZs molded ear wrap thing. You don't ever have to remold or stretch or crimp the thing it just sits on your ear perfectly and always remembers it's shape. The braided cable (which KZ have been adding to all their newer IEMs) is a huge upgrade and honestly I'm surprised to see a cable this nice on a IEM this price. The mic performs great! No issues there. The main driver housing is the same shape as the ZST and for me it's KZ's best shaped IEM for my ear. I've worn these for multiple days straight for 7+ hour listening sessions during work without taking them out and do not experience any fatigue or pain whatsoever. Everyone's ear is different, but these things like my ears.As for the sound, when compared to the original ZST, the bass is more extended, the mids are smoother, and the highs are more extended as well. The signature is a bit more scooped than the ZST, so if you thought the ZST was a bit mid heavy, you'll prefer the ZSTX. That said, the ZST are more comparable to the KZ AS10, which with their extended low and high range are again playing a different game than the ZST.I'm super happy with these pair and would recommend them as an upgrade from ZST.I've been using KZ's earphone since when I bought ZS10.I loved it but it gave me pain in my ear with long-term use.After that, ZS10 was broken cause I washed it with my jeans. So I tried ZS10 pro that was new and 4BA+1DD.The sound was perfect to me. It doesn't give me pain to my ear when I listen music for a long time.My GF told me to buy her something similar with mine(which is ZS10 pro), but actually I didn't wanna spend a lot of money even though zs10 pro is about 50$. So I decided to buy KZ-ZST X. AND this is my opinion...1) It just have a identically same outfit as ZS10 pro. It has just a little bit of change with material ( ZS10 pro has a 'metal-lish' outfit, but ZST-X has colorful 'plastic' but not cheesy outfit.2) The sound is good. Compared with ZS10 pro, amazingly has a similar tone of sounds. Although ZST-X is a 1BA+1DD configure, they tuned very well with ZST-X.These reasons are why titled my review as "Practically Brother"and...3) It's cable just looks like silver braided. ZS10 pro was much more expensive then ZST-X, but It was provided with copper braided cable. So I wanna give much more credit to KZ for making this decision.The sound itself is worth more than the price. If u wanna give a try to a KZ's earphone at first time of your life but have no clue with it, This will be your best choice.I walked into the sea on holiday, I forgor ? they were in my pocket - walked out after I was hip deep, and left it on my beach blanket to dry. Later I left it on my room's radiator, and finally plugged them into my phone to see if it worked.Results: Dolby Atmos turned on which meant it was receiving power and signal. Audio quality was untouched.In terms of the earphones: a great pair which allowed me to hear instruments and vocals I usually wouldn't hear.Comfort: it's minor, but the left ear bud slips out sometimes, but if I give it a gentle refit it usually doesn't move at all.Sounds stage: yes, very good.Microphone: whilst walking and having the mic rest on me, (as a quiet person) it would usually be fine for the caller apparently (no need to put it up to your lips).Total length: about 120cm (estimate because I'm 190cm).Firstly it is very well constructed, from the cable to the casing and fit.It fits well with good isolation, but it's not the most comfortable eartip or casing design for me. But it's good enough.The sound stage and detail is incredible, likely due to the large casing and 1BA+1DD design.However due to this design, it seems as though it can't represent the fully frequency spectrum equally, meaning that you're left with this VERY V shaped sound which if you're sub-bass sensitive will make you uncomfortable. I've tried fixing this with an equaliser and it gets close, but in my opinion that's always an unideal solution that won't fully utilise the hardware capabilities, since it was designed around this V shaped signature.I think a single dynamic driver solution like the Sony MH755 or Tin T2 or Blon 03 would be better at this price point vs multidriver hybrids like this ZST X or its KZ, QKZ and CCA chifi cousins.If you prefer tonality (more neutral sound signature) vs detail then I would recommend one of the 3 single driver earphones I've listed above. If you don't have much experience with audio gear and love boomy bass then go ahead and buy the ZST X, but if you do then you'd be better off buying directly from AliExpress where you can find the higher tier KZ/QKZ/CCA models like the KZ ZS10 Pro or CCA C10 which have many more dynamic-drivers/balanced-armetures (DD/BA).I bought a set of these to replace a set of more expensive shure in ear monitors that I use regularly for gigs and rehearsals with my band.The shures were around 3 times the price yet broke unexpectedly. I wanted an affordable set of in ears to not break the bank after my negative experience with the shures lifespan and I stumbled across these.After using these regularly at gigs for an in ear monitoring system, all I can say is wow...absolutely stunned by these, they sound absolutely phenomenal. Rich, warm, lovely bass which I personally really like in headphones and clear highs. I have to say I didnt really love the Shure sound it was clean and pure but a little sterile for my taste. These have completely transformed my gigging experience. My mix is now incredibly rich and warm and I've been really enjoying wearing them as much as no in ears. With in ears and isolation you usually lose that 'in the room' feel of a band/audience, but these have been phenomenal I've been loving my mix. They go over your ears really nicely and sit in comfortably. One potential downside is I think they'd benefit from having a little catch or cable tie that you can use to tighten them if you have them over and in your ears, as sometimes if you run them down the back of your shirt, I'm personally used to the shures having this so I could adjust the fit nice and tight down the back of my neck and over the ears, but this is only minor. They come with mutlple sized ear buds which is useful for you to pick a size that fits. I'm glad they aren't the thick foam tips, which do offer greater isolation but in terms of cleanliness and comfort, foam tips weren't for me, but you can easily buy a set!The color is awesome and they look great in too on stage.If you're looking for a set of in ear monitors as a musician then look no further. These are stylish, comfortable, and above all sound great, they'll give you a rich mix in your ears. So glad I decided on this pair and hopefully you do tooHonestly these IEM's are really really good and that is not considering the price either. They have crystal clear mids nice and sharp highs and deep punchy bass which doesn't interfere with the mids keeping the whole sound stage nice and wide which is very unusual for in ear monitors (they usually have a more closed feel) but no these have excellent sound stage which makes listening to things like the witcher 3 sound track sound amazing but the extra bass makes them also equally amazing for listening to artists like juice wrld or x. Overall these IEMs really suprised me on how good they actually are I only bought these just for something compact to game with and they ended up replacing my headphones. Would definitely recommend to anyone audiophile or not.Wow, these are phenomenal for the price. They are a comfortable fit and sound really good. I have been using them for conference calls whilst working from home and the sound is great.The only very minor point, is that it could do a small moveable sleeve on the cable to tighter the fit at the back of the head. However, I have improved with a very small tyre wrap which works fine.