So I have been in the dark about TFZ and their recent rebranding efforts in EarAcoustic. TFZ is not new to me as I have done a handful of reviews for their TFZ and Super TFZ line of IEMs. Apparently they have changed their branding a few times in that regard. I always wondered what the Super stood for in front of TFZ, perhaps their best efforts? It has been a while since their last branded TFZ IEM so I was wondering what has happened to the group, and now I know. How about changing the name altogether to EarAcoustic? Another aspect of this name change also comes with a bit of contention in that EarAcoustic seem to have released something like 20 or so different IEMs out of the gate. 3 different series of IEMs consisting about 7 IEMs for each series. To be specific. The STAR series. Which the STA-K is one of them and with 5 others in the STA line up. SPARK series with something like 7 IEMs. And what's called a vocal sweetness amplified series or VSA series, which consists of 7 IEMs. Not 100% certain on the IEM count but that is a lot of IEMs released all at the same time.
Releasing so many IEMs at once causes some issues, one of which is how does a person actually go about choosing which IEM is best for them? I don’t know a single reviewer or online persona that has actually heard all these IEMs and brought out a usable listing of what every IEM sounds like so there is no possible way you will know what version of whatever IEM you are getting for your money. That is the biggest issue. It's like that parable of chasing the rabbit. If you go for one, you might actually catch it but if you have too many in front of you, how do you choose and which one you go for? From how I understand it, reading other reviews of the EarAcoustic line up, each IEM in the series represents a sound direction or tuning aspect but each IEM has slight tweaks from that sound formula. So it is up to the purchaser to somehow figure out which is best for them? You also have to take price into consideration but. As they say, too much is too much. One would assume the highest end in the line up is the most refined for that particular signature but that is just assuming.
I think what would have worked better for EarAcoustic is to bring out the best version of their series and just released one or two IEMs for that series that represents the best tunings and ability out of the many they have released and called it good, like most IEM manufacturers do. But no, you get to choose a myriad of IEMs and each one represents a bit of a tweak to the sound formula. In any case, why am I bringing this up in a review of just one of their IEMs? That's because It's just one of a series of products in the same line that are supposed to be similar? I have no idea. What I will do here is bring some light to just one of their new releases in the Star line up STA-K. There is so much confusion for their releases but at least we are focusing on just one of them. Trying to chase a single rabbit.
In relation to their 3 series of IEMs. I do have a good idea why they might have gone this route. First of all TFZ is not new to the IEM game. I do believe they have over 10 years of experience making IEMs. Everything from budget to more expensive higher end mid fi offerings. TFZ has made vocal, stage, dj and brightly tuned monitors for the Chinese community as well as a myriad of musical listening IEMs for the street. So it seems they have focused on particular tuning aspects to bring out their 3 distinctive series of IEMS. Star series seems to be about consumer grade listening or for the street and not so much for monitor vocal type of tunings which I assume is their Vocal Sweetness Amplified series. I am going to guess that their Spark series is more audiophile analytically tuned IEMs.
With that, I would like to thank Keephifi for the review sample of the EarAcoustic STA-K. These IEMs can be bought on keephifi site
here. The STA-K was provided for the purpose of a review. They have been burned in for a period of a week's time and are now ready for evaluation using my sources. IBasso DX300Max IBasso DX180, Fiio M15S, M15, K9 pro ESS, IBasso PB5, IfI Gryphon, IfI signature for amping. By the way I highly recommend a burn in, it uses 2 dynamics both of which need that time to gel with each other.
Onto the review.
The STA-K is a dual dynamic hybrid IEM. It is using a 10mm Beryllium plated dynamic which seems to be handling the lower mids to bass and a smaller 6mm PET dynamic helping out the mids to trebles. Upon hearing the STA-K for the first time, they immediately reminded me of a Super TFZ IEM I reviewed circa August of 2022 called the Force1. Those were using a single 10mm Beryllium plated dynamic with dual magnets which I am assuming is very similar to what the STA-K is currently using. I will actually have to compare the two products as they share more than a few aspects of their make up. They seem to also be sharing similar tunings as well.
I remember at one point in the early 2020s, Beryllium was the “ it” material. Anything with Beryllium plating or even more rare a pure Beryllium dynamic IEM and it has to have a next level sound. From my experience Beryllium plated or pure IEMs all have a rich tonal quality about them which makes your sound come off more musical, emitting an exemplarily natural warmth and bodied in its tonal qualities. Not to mention producing some of the juiciest bass renditions possible for IEMs. Hence this is the reason why the STA-K 10mm dynamic seemed to be focused for its lower mids and bass. I can see a scenario where TFZ maybe had too many of the dynamics that was used for the Force 1 laying around and eventually reusing them for what is to become the STA-K? What was old is now new. I have no idea what their design process was or how they came up with the idea behind the STA-K design but I am just guessing at this point.
I can safely say the Beryllium craze seems to be a thing of the past but at the same time, there is no denying what this material does for your average Dynamic driver when it comes to sound. What is interesting however is just based on the prior Force1 performance. That driver can and does easily handle the trebles to subbass with no issue whatsoever. So why the need for a smaller 6mm PET driver? Apparently it was needed to bring clarity to vocals with better instrument separation. Initially I was under the assumption that the treble was handled by the PET but it seems the PET is used more to enhance vocals and mids layering for the sound.
What it comes with.
The smaller square all silver box comes with the earphones themselves, a skinny tangly silver plated OFC cable in single ended termination in 3.5mm with a single set of silicone tips in S,M,L sizes and that is it. No pouch, no case. I suppose you can’t provide a decent pouch for a budget level IEMs which cost nothing but hey I am not the one making the IEMs. What matters here is the sound.
Sound
The STA-K. It's mostly a balanced full bodied presentation and sounds a touch v shaped in signature with treble focused on lower trebles and its bass is more focused on sub bass. The STA-K has a mild treble roll off by design. Which is another reason why I am assuming the STAR line up is more of a musical consumer grade of IEM. The Spark series I am going to assume is where the brighter tunings will be had. Its technicalities while touting an extra PET is not exactly an enhancement from how I am hearing its sound. It's definitely well focused and balanced for its tuning with mostly a natural tonal character with good timbre but it's not the most technical set as you would imagine being a more budget friendly offering. Bass and mids are the focus for these and for a budget level set this is what makes the STA-K stand out.
A bit of a lost opportunity is that these should have come with a balanced cable for modern day players or at least an option to come with one, I say this as they really start to show their stuff when amped properly or from a source with more power. Generally a balanced cable will get you more power. This review of course is done with its included cable but if you really want to hear how good these can sound. I personally recommend a balanced aftermarket cable and your favorite aftermarket tips. Its included tips are a non factor in my view. They work but that is about the limit of what they do for the STA-K. Limitations on what a manufacturer can include for a budget set. I can tell they put 99% of the focus of their efforts for its sound at the price point and not much else. Not the cable, not the tips and certainly with the non inclusion of any type of carrying case or even a pouch to go with it.
I would imagine once you go up in the STAr line of IEMs they will include more tips and a basic case. I suppose this budget offering was made to get you more curious of their higher line of STA offerings? In that regard they have succeeded. What you are getting for your hard earned $50 is a sound that is not common among its peers.
So far the standouts for its sonics include a nicely spacious moderately wide stage. While not the widest or deepest of IEM presentations it does have a nice example of a spacious IEM sound for what I would consider moderate stage and depth. It does have some nice height to the sound that rounds out how the stage is perceived. Much greater than recent budget BA hybrid sets I have reviewed. Stage has a nice spherical effect to it meaning the sound has a surprising atmosphere to its presentation. A bold forward sounding IEM with bass and mids that are the hall mark of what this sound design was going for. The tonality is rich, slightly warm with a full body of note which is once again difficult to find for this price range. Its natural tonal character includes some accurate timbral characteristics. Its attack and decay of sound in general is to be commended but it is afterall, a budget set.
Its negatives include the need to amplify them for better sonics. While they drive fine from any source it is clearly evident to me they scale to much better more powerful sources. The more detailed and neutral your sources are the better it synergizes with the STA-K. I suppose for many this will not be a negative but they clearly put it on their marketing that they are easy to drive. Well yes and no. Its included accessories are meager at best. As mentioned above they clearly put the bulk of its design on the drivers and tuning for the IEM and not much else. Which again is not necessarily a bad thing especially if you already own better aftermarket cables and tips. Its looks are a bit preteen. What I mean by that is they look so blingy they look cheap. A bit like fake diamonds kids like to use to look like their favorite sports stars. Chrome accents with a blingy diamond sparkly like faceplate. Thankfully the sound is better than how they look. Not the most airy extended treble response. I would put the trebles at a smoother clean listening experience but treble heads need not apply to the STA-K trebles. Which leads me to the breakdown in sonics.
Trebles
Is more of a safe smoother listening treble as its main focus is its lower trebles. This works well to bring a basic foundation for trebles. It has decent extension but nothing noteworthy or does it have the best treble shimmer. I do believe it was tuned that way for easier listening. Its treble note plays more of a supportive role for the mids and bass end more so than standing out in the mix. The trebles by its marketing terms are described as smooth and airy. I agree with the smooth part but airy? Not as much. To my ears, the treble note is defined well enough but it's just there and lacks a bit of micro detailing. The better aspect for its treble presence is that it does sound natural to the ears not emitting any metallic timbre of cheaper BAs that are commonly used at the price range. However I wished there was just a bit more of it a db or so more in the same treble regions that it is tuned with would have done excellent for the STA-K tuning. But that's just me. Overall it's fine, especially for folks that are not fans of too much trebles in their presentations. I suppose they had to leave something for the next tweak to happen for their STA line up of IEMs. I am guessing that the higher end offerings has better balancing in that regard especially when it comes to trebles.
Mids
Now here is where things get a bit extra, to my surprise the extra 6mm PET apparently is utilized to help out with the mids presentation. Mids have a slight forwardness, enhancing vocal presentations. Its technicalities for its mids presentation is once again nothing special or a stand out especially when comparing them vs multi BA hybrids which does better for sound imaging, sound separation and detail elements but for what's there the layering of its sound presentation is a stand out at the price. It does emit a dimensional character which was unexpected given the price point. I can understand why EarAcoustic is throwing out this dual dynamic tech for the STA line of IEMs. Its layering for the mid bands gets a boost in performance highlighting vocals and instruments and perhaps it also helps with its greater note weight for both aspects here as well. Unfortunately its imaging is not as well defined as with multiple BA set ups but it has to do more for the innate nature of driver tech involved. I have done reviews for 4 DD IEMs 3DD IEMs and now 2DD IEMs in the STA-K. All of them have good to excellent timbres with a more natural leaning tonal character. But they all lack the reason why higher end IEMs go for BAs instead. For casual listening and modern genres of music this works just fine. However I do feel perhaps their higher line of STA IEMs should do better in that regard. The resolving ability of these two dynamics being used is just average if not solid for sub $100 level IEMs which is not a bad thing. You are getting what you paid for. The better aspects however do outweigh the negatives. Mids are surprisingly rich sounding with excellent note weight to the sound and comes off natural in execution. Which I can’t say about even more expensive IEMs that utilize even more drivers than the STA-K. Here is an example of using the 2nd driver to help with what the main driver does and it works. Hence the STA line up seems to be using ever increasingly more resolving drivers going up in the price ranges. Again I have no idea if that is actually the case here but I am just assuming.
Bass
This is the area I feel the older TFZ and now EarAcoustic folks specialize in. It is very clear to me that the bassy IEMs will be the STA line up of items including the STA-K. Beryllium plated dynamics makes bass presentations exceptional and the STA-K pulls off brilliant renditions of an impactful and extended bass end. Marketing describes the STA-K as punchy and well controlled. Using dual N50 magnets which equates to a tesla flux of control. The bass end definitely got the punch and that Beryllium rumble I recognize going for it. I would say it's controlled but I do recommend a burn in for these as stated before to shape up the 10mm dynamic to play nice with the sound. Open box listening, the bass was there but other parts of the sound were not as clean as I hear it now. Bass gets better control and tightness with burn in and that is reason enough to burn them in. Bass end is organic in nature and is more than punchy when called for. Its sub bass rumble is exemplary at this price range and shows how good bass can be at the price point. Budget sets can do bass well just because this set is cheap does not mean the bass end goes with its price point. I own the now very rare Dunu Luna which is a pure Beryllium dynamic flagship IEM and even though the dynamic used for the bass end for the STA-K is not a pure Beryllium driver, I am clearly hearing aspects of its tonality for its bass presentation. Bass is satisfying as it was on their prior street IEM the Force1. There are so many aspects of how this STA-K sounds that remind me of the Force1 that it seems like they utilize the same exact dynamic driver. Its full bass end is a bit short of basshead territory but is satisfactory nonetheless. Again I would imagine the higher end STA offerings to have a bit more bass presence?
Overall
These were a pleasant surprise, generally budget offerings don’t have musical sounding IEMs that are like the STA-K. Last time I bought a hybrid at this price point the treble was so sharp I could only listen to a few tracks and I had to take them out of my ears and this was after I burned them in for a week straight. Or the opposite with bass so bloaty and ill defined there was no mids to speak of. Then I notice some budget IEMs try to mimic higher end IEMs but to only sound cheap in the process due to its driver limitations. Not so with the STA-K. The driver combination here is interesting, certainly not new to have dual dynamic drivers in an IEM but it was more how both are used together to achieve this big bold spacious sound the STA-Ks have. Organic bass, rich bodied mids character and a smooth treble note in a spacious stage sound good to you?. That is what the STA-K offers for its measly price of admission. You have to be realistic with a budget set however but these sound good regardless of money spent on a set. Sure they can have better micro detailing and even better imaging but I suspect EarAcoustic had to leave some of that on the table for their higher offerings in the 20 or so other releases they have. To be completely honest, if they just released this STA-K I would have been just fine with them. If you want a taste of what the folks at TFZ now EarAcoustic are up to. I do suggest giving the STA-K a try. It will change your outlook on what budget level IEMs can achieve, but please for the love of god, burn them in. Thanks for taking the time to read.
