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Review - Heir Audio 10+ Universal IEM

Let’s get straight into the song of choice which is by Doug Macleod and the track is Black Knight (CD – Rip in Flac); a great Acoustic Blues song from his album ‘There’s a time’.  
His guitar playing sounds lifelike with thick and rich tones; you can clearly hear him plucking the strings and finger movements on the fretboard of the guitar.  The bass player sounds very nice with excellent depth and impact; the drummer in the mix can be heard slowly brushing the skins of his drums.  Then when Doug sings his voice is slightly projected forward with his silky rich tone.  
The soundstage of the Heir Audio 10 is very wide with a good sense of depth and instrument placement and separation are T.O.T.L.  The bass is big while the sub-base goes very deep.  The mids are slightly forward and liquid smooth and resolving with no upper spike.  The treble has plenty of shimmer and great extension with a good amount of body.  Overall I would say that the Heir 10 has a big sound and slightly on the warm side of neutral.  It also has good macro detail and is musical because of its slightly elevated bass.  
The Heir 10 has expanded my perspective to include a wider range of genres of music as opposed to listening to a narrow range of music.  I now enjoy a greater variety of styles.

Heir 10.A Review by Frantisek Bina

Sound Quality

There were many players used for testing of Heir Audio 10.A. From classic Sansa Clip Zip over Fiio players to high-end Calyx M and Hifiman HM901S. Even though Heir sounded wonderfully even from basic Clip, each step up in players was clear improvement. IEMs of this category really deserve appropriate portable rig, so investment into some dedicated Hi-fi player is worth it.

When many other IEMs try to impress on first listen with one particular range, Heir 10.A is more about whole presentation. They are little bit mid-focused, but no part of sound is too enhanced or suppressed. Thanks to that, they sound balanced and natural. They are great mix of extremely clean sound with ton of details with pleasant and engaging sound, that will keep you wanting to listen for many hours.

Bass has great impact, sounding full and strong when needed. Yet it’s never too much and bass never bleed into midrange. There is no enhanced mid-bass and Heir are really truthful to recording in quantity of bass.

Really good are technical aspects of bass, great control and speed, that surpass almost all IEMs I tried. Not even my old JH Audio 16 with 4 bass drivers couldn’t catch up sometimes.

Great bass extension and little bit enhanced sub-bass adds fullness to instruments and offer great rumble needed for classical and movie music. Many other BA based IEMs has problem with this and it’s one of reasons we see more hybrid IEMs lately. But Heir 10.A manage it great with just two balanced armature drivers, probably biggest that you can get from Knowles.

If bass was great, midrange, strongest aspect of Heir 10.A, is just amazing! It’s little elevated and adds slightly warmer tone for more pleasing sound. Voices and instruments sounds full, alive and engaging, they really draw you into the music. Even though there is warmer tone, Heir 10.A offers great clarity and amazing detail, surpassing most IEMs on market.

Highs are balanced between enhanced, energetic and smooth. They are not harsh and don’t sound artificially, they go really high with great clarity and with enough air. They might be little bit strange in the beginning, if you go to Heir from brighter or darker earphones. I myself always preferred brighter sound and I needed to adjust to more relaxed highs of Heir 10.A

As many other customs, Heir has great presentation of space. Soundstage is large, but main advantage of these lies in localization. Each instrument has it’s own place, strictly separated from others. It’s easy to locate it not just in direction, but also in depth of soundstage. I always use song This is Halloween from the movie The Nightmare before Christmas and no other IEMs I tried managed it complicated soundstage as good as Heir 10.A.

Heir 10.A are not for bassheads, neither for people looking for cleanest analytical sound. They don’t offer huge coloration and their highs are not super sharp. They are simply really pleasing, natural and fun IEMs. And you will enjoy them everyday.

I had few high-end universal and custom IEMs in past, but non of them managed to offer so clean and controled sound with so natural and fun presentation. For me, Heir 10.A are simply the best IEMs I ever heard. If you are interested enough in portable audio, Heir 10.A gets my highest recommendation. You will not be disappointed.

Heir Audio 10.A :- Musical Masterpiece By Willis Mattoali



Before you read this review, ask yourself this question. “Why do I like to listen to music they way I do?” In the world filled with audiophiles, music enthusiasts, and the general population; music has  entertained us all. The sense of sound is an intriguing sense in a way that sound can evoke and inspire memories or feelings unlike any other. This reason is why I personally listen to music the way I do. Why I spend so much time, effort and money; Why I treat it as more than a hobby; Why I am always on the quest to please my ears. If you haven't found the answer to :“Why do I like to listen to music they way I do?” , I hope this review can inspire you to find this answer.


Previously in the Game of Tones, house Heir Audio had a beast with 8 drivers that caught my attention and persuaded me to shell out my earnings. Sunny a representative of Heir Audio notified me about a new creature with 10 drivers being created in Sichuan, land of the giant Pandas. When it came time to unleash the beast, Heir Audio declared a black Friday special discount which I could not turn down. Thus was the start of a majestic relationship between the 10 driver CIEM and I


Fit & Order


Heir Audio are one of the finest crafter in the CIEM market. They have a large collection of samples and options to choose from.  Few can rival their beauty nor personalization. Another reason why I picked Heir Audio is their location. As I am in Beijing and they are in Chengdu the shipping became much easier. Time and costs were saved substantially as I had to ship it back due to fitting issues. I did not incur taxes as well. For folks who live in China who craves CIEM, this can be a major factor


When I received my 10.a the fit was unbalanced, and it had to be reshelled for the right fit. I think this is due to the ear impressions which were not properly made. After reshelling, the CIEM slips in like a glove. As this was my first CIEM, it took me 2 days to get used to it but, it really just disappears as you wear them.


I personally requested the design of my 10.a and Heir Audio molded it beyond the image I had in mind. Looking at it in person is truly a thing to behold. Many of my friends were gob-smacked by it and I even had a stranger walk up to me and ask what it is. The acrylic shell used is non-allergic and very well made. It looks like it could take a beating or two (I wouldn't beat it though) and will still look stunning.




The 10.a arrives in an otterbox with a gold plaque. A change from the aluminum plaque in earlier models. Inside you will find a cleaning kit, 6.3mm adapter, airplane jack adapter, an extra cable with microphone (white for android, black for iOS), and a VIP membership card. While not as luxurious as others, this VIP will prove to be more valuable. Heir Audio is a true pioneer in their after sales service and benefits.


If I am not mistaken, they were the first company which provide a ownership transfer service where one pays $99 to refit their second hand CIEM to a standard model and enjoys an extended 1 year warranty. With the 10.a they have provided a never before seen benefits with the VIP membership. The main benefits of becoming a VIP member are; 10% of all new orders; one time 20% discount after successful referral; Free shipping twice (Mainland China); and a few others


Heir Audio has breathed new air to the customer service aspect of this industry. This will encourage customers to be loyal and purchase future Heir Audio products. Considering how good their customer service is, I am inclined to say that they might have the best customer service I have ever encountered. Sunny always updates me with the process and replies me very fast. An added bonus for impatient people such as me.




Before I describe the lows, mids, and highs I have to declare how impressive the imaging is. The soundstage is MASSIVE, and the layering is great. One of the biggest quarrel about IEMs is that they have small soundstage but, 10.a absolutely destroys that image. I personally think that 10.a has the biggest soundstage of any IEM out there. The soundstage is on the same level on mid-fi headphones. This baby stretches my ear to an extent I wouldn't believe. The first time I heard it I was floored by how wide it is. Instruments are flying left and right with precision and detail. Airy Fidelity posted a review video on Youtube, describing that he feels that the 10.a feels like having a speaker playing around you and I completely agree with this statement. 10.a projects sound unlike any IEMs I have heard. Live and orchestra music utilizes this feature most. Listening to Adele's Live at The Royal Albert Hall is an absolute joy. In moments of magic, I could actually differentiate some of the voices in crowd as they sing along.


One of the strongest attribute of Heir's 8 driver model is their bass. When the bass slams, it feels as if a cranium is bashing your skull. Sometimes though, the bass gets in your way as it takes the spotlight from the mids and high. It is an addicting quality but, in the 10.a they have made it more “professional”. Fast and precise are the two words I would use to describe the bass. The IEM 8.0 is like Mike Tyson punching hard with authority. Comparatively the 10.a is like Muhammad Ali; Picking its shot, fast, agile with laser like precision. Listening to Armin's Intense sends me to ecstasy, the bass rumbles low to an extent that I have not heard before. Quality and not quantity is the name of the game here.


The mids are slightly forward with a hint of of warmth, just a hint. I've always lean towards the warm side of the audio world  and 10.a has found the right balance with the warmth. Vocals sound crystal clear and sang with a gusto. Numerous of times I've tried IEMs with great clarity but lacks “soul”. I felt no emotion, it felt as if a machine was singing. I'm pleased to say that 10.a does not have this problem. Tonally there is nothing wrong with the mids, and the soul of the singer are ever present. On one occasion, I was sitting with my eyes closed in the crowded subway of Beijing (only Beijingers would know how crowded it gets) and was listening to Ella and Louis' Moonlight in Vermont and the way the 10.a “sang” made me forget where I was. The tender voice of Ella is a thing of rarity. My imagination ran to a cabin somewhere in Vermont in the midst of a cold winter night.


Heir Audio's biggest change was it's treble. In IEM 8.0, treble was smooth and it did not extend too high. They have resolved this issue and 10.a's treble extends high without getting too hot or fatiguing. Rock is the genre I listen to least cause, treble more often gets too hot, and due to this instruments get mixed and jumbled up. All 10 drivers works hard to prevent this from happening. Treble always remains pleasant and detailed without bleeding into the mids or lows.


The 10.a made listening old music new. What do I mean by this? All of us has albums and records in our collection which contains a lot of memories. As time progresses and we grow older we tend to forget about most of the music we listen to when we were in school. Plugging 10.a to my Calyx and playing it shuffle made me listen to Simple Plan's Welcome to My Life. Memories of my middle school days overflows my brain and I think to myself: “I've never noticed that the guitar strums this way, or the drums beating like this.”


If I were to portray the 10.a, it would be like eating at a fine dinning restaurant. The chef has designated the menu with an experience in mind. Each course is served with perfect balance and with the next dish in mind. While not a food, the 10.a exactly does just that. Not too much of this or too little of that. Everything sounds and feels as harmonious as it should be.



Sources and Amp


The IEM 8.0 needed an amp or a good source to perform. Heir Audio somehow made the 10.a easier to drive. I have no clue how they could make a 10 driver model this easy to drive with almost no hiss and a black background. IEMs with many drivers, especially 10 would usually be more sensitive. Yet the 10.a has improved this issue from their previous flasgship. 10.a could perform admirally from my Note 3. Sure my Calyx M is superior but, I could happily spend a day with my Note 3.


DX50 + Rendition 1


This set-up is a pleasant set up with surprisingly wide soundstage. Although mids and highs sound great through the set up but, I found the bass lacking. When the bass hits, I felt that it was loose compared to my other set-ups. Interestingly I enjoyed this particular set up more than a lone AK120 II.


AK120 II


Pairing it with the AK left me disappointed. That gorgeous massive soundstage is reduced alarmingly. Amping it with the Rendition 1 helped but, with it's not worth its price tag if you were to pair it with 10.a. The “soul” which is important to me is nowhere to be found more often than not. Although it is analytical, I find myself listening to AK the least among all.


Calyx M


Now this is the magical pairing that the 10.a deserves. As I mentioned before I tend to lean to the warmer side and the Calyx M provides the 10.a what my other set-ups can't. The analog signature of the Calyx M adds a touch of warmth which I love. Vocals sounds blissful while the lows and highs also gets an added improvement. What came as a surprise to me was how far the Calyx M is ahead of the AK120 II. The AK was always a few notches bellow the Calyx. Even speed and detail retrieval is superior with the Calyx. I thought that it would be a close fight between the Calyx and AK but, this is more like Real Madrid vs. Basel than vs. Barcelona


Like Nathan mentioned in his review of the Calyx M, adding an amplifier just gets in the way of your enjoyment. I preferred pairing the 10.a with a lone Calyx M than with an amp. This pairing will bring out the tenderness is voices that has it. The tonality of he 10.a is a match made for “Kings”




First of all I would like to congratulate Sunny and the Heir Audio team for the marvelous job they did with the 10.a. In the beginning of the review I asked of all you, “Why do I like to listen to music they way I do?” For me it was feelings and memories, that's probably the reason why I bend towards the warmer side of things. Yet as I progress in this audiophile world, I demanded my set-ups to also excel sonic wise. To have the most minute of details appear effortlessly without compensation.


Heir Audio has struck gold with the 10.a Pairing it with the Calyx M made things much more awesome. At $1399 the 10.a is priced a few hundred bucks lower than the competition. From the looks of it they have not only beat the competition with the price but, also probably have them beat with the sound. Sure the packaging is not as nice as others but, their innovative customer service will prove to be more useful than a fancy box.



In the ultra competitive “Game of Tones” many houses tries to claim to be the rightful King.  Heir Audio's new Heir the 10.a is certainly a strong candidate for the throne of Audioteros. Their 10 driver creature is a thing to behold and other houses should fear it. I too am a king....well, king of my quarters at least. I consider the 10.a to be a fit for me and therefore I can verify that Heir Audio's 10.a is “Fit For A King.”

Heir Audio 10.A - Wisteria, Sorry I Mean Hysteria

May 11, 2015

Sonny Trigg

Heir Audio turned up in headphone scene around the same time as me and their climb to success was shockingly quick and the reasoning was clear. They were the first company to really push forward the level of customisation in a custom in-ear monitor (CIEM), yes companies prior to Heir had offered customisation but not on the level of Heir. It was also the first we saw of wooden faceplates in this product space, something that is now an offering from all the major brands and although it shouldn’t be, it is easy to forget that Heir are indeed the pioneer of wood. Even though their original product line consisted solely of custom products, I have now reviewed 3 models from Heir but never has one been made to custom fit my ear. Obviously the success wouldn’t have held if their products didn’t impress in terms of sonics and the original flagship, the 8 balanced armature (BA) 8.A, seemed to hit the spot with most buyers. That being said the 8.A started to age with it still being the flagship in late 2014 and Heir only bringing out new universals and lower end models. On top of that while I can see why people enjoy the overly warm, lush and thick sound of the 8.A (I have the universal version, the IEM 8.0), it isn’t a technical masterpiece or really up my preference street. Moving into 2015 I think it was clear a new flagship was needed, it surely had to have more balance and be technically better and obviously I wanted to finally check out a custom fit product from Heir. GIANT SPOILER ALERT: They have done all 3, welcome to the 10.A!

10 Precision Tuned BA Drivers:


Well that’s what Heir claim to be using in their brand new flagship, the 10.A. Using a 4 way crossover and a single twin driver for the lows, highs and curiously named ultra highs along with two individual twins for the midrange, there is a lot packed into Heirs beautiful custom made shells.

Talking about beautiful shells and you just have to look at mine for a sample, or any posted on the companies social media pages (they do them all, look up their Facebook or Instagram) and you will see what I mean. At the moment it seems like they are in love with using gold, throwing pure gold leaf as a faceplate and even floating in the shells. They also obviously use a plethora of different high quality woods, carbon fibre, metals and even PCB boards. Guess what, for me this was just too much, I had no clue what too choose, did I go for a classy gold design, something real simple and clean or even a unique crazy design. I got in such a state of excitement I ended up just telling them to make me something awesome and they delivered.

Heir went with a blue theme for my monitors, for the faceplate, a special blue carbon fibre and the shell, a translucent light blue. On top of that to get a bit of gold into the design, they engraved the Inearspace logo onto one faceplate. Now funnily enough the only customisation option of all that you have to pay for if your buying the 10.As is the engraving, which would be between $45-$85. Most faceplate designs come free including wood, carbon fibre, mirror and PCB and you only have to dig into your wallet if you want both channels to be different or something crazy such as wood and carbon fibre hybrid or woven grass on the faceplate. In fact as a laugh I recommend going on Heirs website and just having a play with all the options available, they are so vast, I just wish they had a JH Audio esque web designer to make visualising a design a bit easier.  Nothing beats actually seeing how different options compliment each other.

The actual quality is really top notch and everything just seems like it is done with a sense of artistry about it. The blue shell, a seemingly simple option is almost completely clear at some parts but then on the curves it is a much deeper blue, its gorgeous. Then you have the faceplate, which is carbon fibre, much like many other companies offer, but do they offer blue? Gold? Green? Or even patterned effects in it? Probably not! On top of that the shell is completely bubble free and our logo, not just engraved but in a rich gold. In something as subjectively appreciated as design, these are by far my best looking customs to date and are finished spot on.


As for cable this like the IEM 8.0 comes with Heir Magnus 1 cable, which you can read more about in the just mentioned earphones very own review but to save you the time, it a top level stock cable. You also get a new cable, one that comes with a remote and mic. The quality isn’t near as good as the Magnus but if you want the smart phone compatibility (they do one for both IOS and Android) then this is a great option, considering getting a stand CIEM phone cable is quite a rarity.

Now the fit is actually a little bit fiddly with these. When I got them the right piece popped in like normal, no problems there but the left caused me a little more trouble. Now with ten drivers a channel, these are obviously a little on the bigger side but that being said, I don’t see myself having near small ears. However I think the trouble was just down to how these are designed. Comparing them to my Hidition Viento-R, they are a little deeper in profile, in fact they do match the 12 driver JH Roxanne there but they are also obviously more present in the cymba and have a little notch that fits under the crux of the helix. Funnily this is just like the ACS Encore and is just a different method of fitting a CIEM where you have to get the body of the monitor under the crux before you press it into your ear. In all my CIEM experience they have all fitted the same way until recently with the Heir and ACS, how odd. Now this method once fitted, is VERY secure and also comfortable, however it does take some technique to fit right and can become frustrating at first. Especially when you just want to pop them in quickly. I will add these were fairly deep fitting as well and the end of the canal portion was actually thicker than usual, not that I felt that in anyway. Isolation was standard brilliance from an acrylic custom.


Sounding Blue:


Obviously I made a little spoiler to the sound early but this is a clear departure to pretty much any Heir product I have ever heard (minus the Tzar models) and like the colour of these, if you were editing them in Adobe Lightroom and adjusted the temperature, they would be more blue than the Heir 8.0s warm orange. Maybe that is a slight exaggeration as these aren’t exactly defined as cold, they actually comes across as quite a clear mid forward earphone. The midrange is always in the spotlight, with a snappy bass on one side and an energetic treble on the other. Even though they sound completely different to the 8.0 one thing I do find to be very similar is just how musical, engaging and rhythmical they are. That in itself is a huge compliment with most earphones of a similar very balanced tuning end up being sterile and boring.


Coming off last weeks disappointing boxing match I have to describe the bass of these to be very featherweight. Quick on its feet with a slightly padded right hook but still without doubt knows how to throw a punch. At least that’s what my first thoughts of the bass were. Then I played around with some different sources, I moved from my standard rig of PWAK120-B to Vorzuge Pure to the Lotoo Paw Gold, then to the Bakoon HPA-01 with either of the two sources line outs. While the character of the midrange and treble always seemed to keep pretty similar, with the standard influences of the source gear obviously taking effect, the bass was always almost dramatically different, in weight, texture, depth, decay, it really was shocking. The explanation of this is likely quite simple and that is the impedance and/or phase plots of the 10 drivers won’t be quite linear enough, meaning they will be really sensitive to different output impedances among other things. So what does this mean? Well mainly it means I have a hard time describing the bass because source becomes such a huge factor. It also means you will have to be careful with what you pair with and get some different capabilities out of these. That being said the first way I heard it, off my modded AK120 and Vorzuge rig seems to be the most recurring and standard way the bass comes across and I really like it. Yes it’s a little bit lean but its super fast, is a bit quick on the decay but coupled with some half decent extension, doing a little better than the UERM but not quite keeping up with the Hidition Viento-R, it is pretty satisfying. While texture may not be as groovy as say the Custom Art Harmony 8 Pro, its dryer with such as crisp and isolated impact and honestly, it hits the spot for me, although I can see it not delivering for those expecting a warm or thumping sound.

As I mentioned this sounding different with other sources though it would be rude not to dig a little deeper and report my findings. Well the must crazy difference was off the Bakoon HPA-01M and more specifically from the current output. It was one of those moments where you do a double take, and I even checked I was listening to the Heirs and not the warm and bassy ACS Encores. The bass was thicker, weightier, it wasn’t quite heavyweight but we were easily into welterweight territory. What was even crazier though was the decay that comes with it; we have a warmer timbre and a funkier but less precise sound. You also got some dirty sub bass, much more so than with anything else. Now an obvious and quick a/b was with the Bakoon’s voltage out, seated right next to the current one that decided to make the bass go hulk on me. Instantly it was much leaner, not quite as much as of the first rig, it was a little creamy in comparison but again wasn’t quite as focussed with impact, we lost that crazy extension as well that the current mode mustered up. Finally we had the Lotoo and this was surely my least favourite of the bunch, it seemed not only a bit weak, lacking aggression in the punch but seemed to be less tight at the same time, bundled with the worst extension as well, this wasn’t for me. Again as I said, the main description in the previous paragraph was the most common finding of the bass, with me getting a less refined version of that sound with most DAPs I have scattered around and even my smart phone.


With that out of the way as we get better consistency, yes source gear will affect the mids and high frequencies but no more than the normal difference you would expect with any other headphones, the bass was just a little more drastic and surprising.


With that in mind the midrange to me was very fresh, an odd term I know but that’s how I found it. It is balanced with no obvious favour to any certain areas (although it does have some obvious and clear body in the upper mids), which is something that should be cleared up for those who saw the 4.Ai measurements. It also done an amazing job of making me connected to and at one with the music, something Josh normally goes on about a lot more than me. You just feel so close to the happenings, you’re at the front row of the gig and as you can imagine, your loving every single minute of what goes on. The midrange really is phenomenal; a sweet timbre that is rich and just makes everything sound grand and natural at the same time. Its breath-taking and making me slightly lost for words, if you can believe that.  On top of the fact that I love it, it is extremely good in all technical areas, it is as refined as they come, everything is painted on a black background with amazing space and separation and the levels of clarity are just incredible. Like the bass these are also quick on decay and they just adds to that incredible focussed sound and while this is a quite lean sound, it is never anaemic or something you see as negative, it is something you just accept because of what it lets these achieve. That quick decay does however give these as overall dynamic sound with good bite.


The treble is probably the worst area in terms of absolute technical level and at the same time by no means bad. I say that because it is just ever so slightly sometimes border lining aggressive and is also a little bit grainy as well. It comes off of the upper mids quite keen and gets straight down to business; it is here where we are just a touch hot. For what I look for in treble, I often use the Hidition as a benchmark, detailed, smooth, bodied and still a little north of neutral. This has a lot of those qualities but seems just a bit wispier, with a touch more splash to it. Obviously it is crystal clear and obviously it extends to the end of the world and back. Strangely it isn’t in the much higher frequencies I find these a touch aggressive; at 10 kHz they have a much more sensible presence, less than say the Hidition’s.


Now from my finding in the bass and expectation that impedance and/or phase curves aren’t the flattest, I find a incredible and tight coherency between everything with these, it is one of the reasons these are so great why they are so punctual and why I keep saying the word crisp to describe them. For everything to be well spaced it is always good if there is err… space…. While once again I find myself saying that an earphone I am reviewing doesn’t have the completely huge space that the JH Siren Series has, I do find this to be the closest so far, getting turned down right at the border. But what it can do much better than the Sirens is image, everything is so much more precise and while they have the width, this adds some depth to the mix to leave you pretty darn amazed.


It’s not the smoothest earphone, there is some grain here and there, and sometimes it even has some rough edges but this thing combines musicality, forwardness, detail and coherency to make what is easily one of my favourite experiences in an earphone to this date, without doubt and expect it do be going toe to toe with absolutely everyone in our upcoming flagship round up.

A Rare Luxury:


Looking at these shiny blue earphones, they look like some rich fancy, jewellery. They don’t come cheap but for some people, a pretty enough product warrants that. But this is one of the rare few that nails every category, from comfort, to build, all the way to the sweet, sweet sound its reproduces and for that reason, it is a great buy and whole hearted recommendation from myself. And before I go, yes I did fall completely head over heels with these and yes I have an emotional connection with this that I don’t have with any other monitor, perhaps.

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