Heir Audio IEM 8.0 Review by Edd Harris

Heir Audio 8.0 IEM Review: As Heir Audio’s flagship IEM the natural warm dark sonic signature may, at first, appear odd. However, this unique IEM delivers a multifaceted experience that is so effortlessly enjoyed for hours upon end. The fit and function of this in ear monitor is superb, and the craftsmanship invested within the rosewood design is beyond stunning.
Review Preface:
Springing into life back in 2011 it wasn’t too long before boutique China based IEM and CIEM manufacturer, Heir Audio, gained serious notoriety on the various, well respected, Internet forums for their class leading sonic performance and exceptionally beautiful exotic wood faceplates. Now, after a whirlwind few years, humble Heir Audio have successfully built up a competitive catalogue of designs to suit all tastes and budgets. In order to remain competitive a almost every design can be ordered as a custom or universal with, of course, the exception being the recently released CIEM flagship; the 10.A. However, today we have the universal fit ‘8.0’ within our mitts and we intend to precision analyse this powerful IEM to uncover exactly what makes it a solid hit.

What Makes an Heir Audio 8.0 IEM:
Just as the product name suggests, each individual 8.0 shell harbours eight individual balanced armatures (BA’s) with a frequency footprint that is controlled by a series of internal passive crossovers. Just as a note for those whom may not be clued in, balanced armatures operate on a completely different principle to conventional dynamic drivers and, although they sport a much more complex design than traditional dynamics, it is their miniaturised footprint that allows for multi-driver in-ear-monitors to exist. Theoretically segmenting each frequency boundary across a bank of smaller drivers will result in a cleaner clearer signal and Heir Audio have chosen to split 20Hz -20kHz into four sections. This means that the 8.0’s utilise two drivers to cater for each frequency boundary, but the details of this, and the components, shall be discussed later on within this review.
Build Time and Shipping:
As the 8.0 is an universal model it does not have to undergo quite the same building procedure as their custom models, but it’s sheer electrical complexity does still take some serious engineering. From confirmation to completion the 8.0’s took a full three weeks with shipping adding another two weeks on top. Heir Audio does ship their products via EMS’ International Priority Mail which is fully insured and we were supplied with a tracking code to keep an eye on proceedings. If you are a UK customer then the package will pass into Parcel Forces’ hands where you will have to pay the relevant import duty and handling charge. If you cannot wait the length of time that it takes to build the IEM then you can pay for a rush order. At $280.00 this is costly considering that it only knocks down the build time to a maximum of seven days and currently there is no option to pay for a faster means of shipping, it is fixed at $55.00 for the fourteen days so it appears to be all very trivial.
US Estimated Landing Cost:
The base cost of the 8.0 IEM is $999.00 USD and with shipping at $55.00 this figure arrives at: $1054.00. For a product of this type the customs fee is $51.65, so you can expect to have a total landed cost of $1160.65 without any processing fees.
UK Estimated Landing Cost:
The cost of the 8.0 IEM in GDP is approximately £638.95 and the shipping converts to £35.18. For this product type the Import Duty and Sales Tax comes to £150.80 making the total landing cost: £824.01. If you include the Parcel Force standard fee of £13.50 then the completed cost is: £837.51.
Unboxing, Features, Build Quality, and Fit:
Initially arriving in an outer box that is adorned with plastic documents enclosed wallets and a wedge of shipping documentation, it takes a strong and sharp knife the get in and reveal the thick soft foam protecting your ears care package. Once inside you’re drawn to the beautiful red foil embossed sleeve which slips off to reveal an 17cm x 11cm x 4cm Heir Audio branded Otter style box, which appears to be larger than what most other ‘mainstream’ IEM/CIEM manufacturers currently provide. The brilliance of this carry case is that it is virtually uncrushable and is built to take a huge beating. Typically these boxes can be run over with a car and still survive, but some of the other features include the ability to be locked with a padlock, which is not included, and an ‘O Ring’ gasket to make this box and its contents weather resistant -not water resistant!

Inside of the case are all the components needed to get you stared and to maintain your in ear monitors including; the 8.0 IEM’s with Magnus Cable pre-attahed, a pair of rubber Heir Audio DAP straps, three sizes of hard red ear-tips, three sizes of blue softer ear-tips, three pairs of double flange ear-tips, an IEM cleaning brush with ear wax hook, and finally, as IEM’s contain sensitive humidity sensitive components, a small pack of desiccant. All accessories appear to equal the quality of those currently included by other competitors.
As standard the Heir’s 8.0 IEM’s include the upgraded, and highly regarded detachable, 1.4m Magnus 1 cable. On its own this cable is worth $110.00 and starkly contrasts the current universal 92pin (dual prong) standard. Whilst there are a plethora of premium aftermarket cables available, the Magnus 1 stacks up well against the competitors and provides a solid, yet flexible, connection. During our thorough energetic ‘stage use’ tests we found that the Magnus 1 cable effectively inhibited microphonics from effecting the output to any notable degree, and its strength was demonstrated by passing rigorous blunt force scuffing tests. By casting an eye over the entire cable structure I would expect this cable to provide many hundreds of hours of active service, but in order to arrive at this conclusion I would like to explain the cable construction and the materials used.
Typically cables begin with a plastic 3.5mm jack, however the Magnus 1 utilises a bomb proof 90° gold plated Neutrik gun metal socket. Inside this socket is a plastic strain relief mechanism which is finally finished with an outer flexible rubber gasket for reliability. Carrying a balanced signal, the 1.4m length cable sports a quad twist braided construction, over the typical tri-braid design, where the internal core conductor is an Oxygen-Free Electronic (OFE C10100) copper cable of at least 99.99% purity with a pure silver coating. In comparison to the stock cables, previously mentioned, the Magnus 1 cable has much more silver content in order to preserve the clarity and brilliance of the signal with minimal distortion to effect the very delicate balanced armatures. Surrounding the core conductor is a layer of PTFE before being protected with, literally bulletproof, braided kevlar and a final aesthetic layer of black nylon. Typically IEM/CIEM cables are made with a nylon protection layer, but kevlar is far superior where it is able to survive a static load test of 1000kg and a dynamic load of 200kg. As the cable comes to the Y-Splitter it surprisingly does not use any plastic housing, instead the cable is split and secured with heat shrink but I cannot see this being too much of an issue, and just beyond this is some small tubing on the cable in order to stop the driver housings from smashing into each other when worn out of the ears. As we move up to the 92pin dual prong there is traditional translucent tubing with a flexible wire to comfortably guide the cable down behind the ear and stop the IEMs from being ripped out of the ear. Notably the pin construction has an, larger than most, metal housing rather than an cheap plastic design. Although Heir Audio do not currently support recessed 92pin sockets the socket has an 3mm gap to allow for recessed socket use, presumably when used with other brands, but this goes down into two very solid gold plated pins and snugly fits into the socket without bending or feeling soft.
Considering the substantial design of the Magnus 1 the cable only weighs a total of 18.4g and feels very comfortable to wear. Quickly the cable warms up to body temperature and provides the soft flexibility needed to feel like you are wearing nothing. In use the cable design appears to not put too much strain on the driver housings and, more crucially, your ears. Another positive point is that the cable coils well to a small size and manages to stay in its position without any memory effect whatsoever, so there will be minimal frustration during coiling and uncoiling.
Now moving on to the shells and faceplates, I have to say that the finish and build quality of the 8.0’s is second to none and, as for the exotic wood faceplates, they are beyond stunning. From the published photographs I knew that the 8.0’s would look great, but seeing them in the flesh is breathtaking and shows that two dimensional images can really do them no justice.
Across the Heir Audio IEM range the shell colour and faceplate option is fixed. Likewise there is a small Heir Audio logo engraved in gold at the ends of the shells with an individual serial number laser engraved onto the inner shell. To be helpful Heir have colour coded the serial numbers so you can easily determine which is left and which is right, yet the inherent design means that when you come to place them in your ears each shell will only fit in one ear so the small thought it somewhat vetoed.
Other fixed design options further present themselves with the use a smoke black shell and an Siamese Rosewood faceplate. The combination of colours works well and the entire item has been hand polished to create a premium glossy look to best bring out the the delicate grain of the veneer. To add a touch of individuality Heir craftsman have matched and angled two individual veneer cuts so that they appear continuous over both the right and left faceplates. In the process Heir have created an individual product, and one that screams both style and sophistication. Something else that I have noticed is that during the different times of the day the organic faceplates develop a different hue depending on the ambient light. There really is nothing like natural materials! With this said, it is unfortunate that you cannot choose the shell colour and faceplate from a list of options, even fixed, at the checkout. Considering this further it seems a little strange because, unlike some other IEM manufacturers, the shells are not mass produced via injection moulding. If Heir could offer a pick your own colour then this would probably suit more individual tastes. However, in the short term, I would have probably picked a clear acrylic so I could marvel at the inner workings, but in the long-term I love these 8.0’s for their understated class. They are beautiful.
Just as the faceplate materials are important to Heir Audio, so are the materials that go into making their shells. For this they use a special medical grade acrylic that is imported Germany, which is then poured into moulds to create a distinctive ergonomic shape that comfortably nestles within the concha (outer ear). The shape then develops with a long 7mm nozzle that is offset at a slight angle to comfortably travel past the tragus and rest deep within the external auditory canal. In order to clamp the ear tips Heir flare the nozzle as it goes towards the end. Thankfully this technique works well and I’ve never had an issue with them getting lost both on and off the ear, but the overall ergonomic shape of the nozzle considerably helps to make the 8.0’s very comfortable during extended periods of listening with a very nice seal. Anecdotally, some other IEM/CIEM manufacturers feature a larger nozzle bore and smaller nozzle length but sadly, due to my small ears, I have found this configuration to be uncomfortable and not rest deep enough into the inner ear, so I send a big gold star to Heir Audio for their unique design. Possibly one small reservation regarding the nozzle is that it has an open ended ti-bore construction with large open canels. This is not an issue whatsoever with fit, but if there was a small wire mesh inserted here then that might help to filter out large particles from travelling deep and potentially blocking them.
Finally, as a note, I would like share my finding that, when worn, the 8.0’s don’t appear to protrude far from the outer ear structure and another important fact is that Heir Audio shells do not cater for a reassessed socket design but, with all facts considered, the entire structure feels very comfortable to the outer ear.

The Heir Audio 8.0 IEM’s use a total of eight balanced armatures with crossovers tuned to the following: 2x BA’s for low frequency production, 2x for medium frequency production, 2x for high frequency production, and 2x for ultra high frequency production. In the process Heir Audio only use the finest materials within their circuits including; US handmade Knowles Drivers, Vishay Inter resistors, AVX capacitors, and OxiCap capacitors.
Burn-In Considerations:
When ‘burning-in’ new IEM/CIEMs please note that a 60 hour procedure conducted over a three week period, at moderate volume, will highlight the sonic developments. Please beware that cranking up the volume too soon can have an impact on the accuracy and longevity of the BA’s when they are meant to be ‘settling’ in.
Sound Quality:
Having monitored the 8.0’s over a standard 60 hour burn-in, I observed a significant transformation. Initially the 8.0’s exhibited an overwhelmingly dark sonic footprint and slightly cramped soundstage with tight transient detailing, however this quickly subsided to reveal a truly lovable character which is something that we discuss shortly. In the meantime I would like to note that this IEM has an incredible ability to be very continuous across a wide variety of source components. To put this into perspective, the 8.0 exhibited an remarkably similar output when using an iPhone 5s against the Chord Electronics Hugo.
Post burn-in, the exposition of the 8.0’s is still surprisingly dark sounding for an apparent flagship IEM, but the way in which it presents these characteristics is rather unique and beautiful. You could, perhaps, objectify the 8.0 as a comfortable chair; ridiculously satisfying and very understated. Under this term it goes without saying that the 8.0 is not quite the concise detail rich monster that you might have expected and it doesn’t require any any thought to listen to, it just aims to give you an clear concise luxurious organic stage with none of the typical ‘look at me’ bravado. It simply is ‘that’ IEM that you go to for hours of pleasurable listening with no questions asked. You never feel audibly violated, and you never feel exhausted. The 8.0 is faithful and it is luxurious. It is, undoubtably, one of the most natural IEM’s that I have come across in its own outstanding way. I do have one minor caveat, that is you do get an iota of coldness despite the thick and full tonal characteristic. This is a common issue across BA based IEM’s, so I will discount it because it does take some guided thought to notice. Otherwise this is a beautifully musical IEM.
Beginning with the bass frequencies, the 8.0 appears to extend very deep, and it does so with slight pronunciation. This characteristic is unique in that it doesn’t merge, per se, into the low mids and create a confusing wash of indistinguishable tones. Instead you have a bass presence which is full and well defined. The bass attack and transient response is good, it just doesn't have super fast attack and decay on rhythmic instruments which would otherwise fatigue the ear. With this said, fast rhythmic elements are presented alongside slow elements which never cross boundaries and both carry a very solid full force weight behind them. Trying to describe the presence of these frequencies is difficult without misrepresenting the timing, but I have never felt anything other than admiration for how well the bass frequencies are carried. Furthermore the staging of bass frequencies appears, once again, average. The instrumentation is well placed and not stuck in the central domain, it does have some width to it that becomes noticed with the relevant instrumentation; ie. tom-tom hits.
Now onto the midrange frequencies… It is apparent that the low mids are forward in the same way that the bass is. This is no problem because, once again, it brings out the fullness of the rhythmic instruments and perfectly compliments the higher melodic structures. It is faster than, perhaps, the bass range, and has a slight dip within the central midrange where the overall tonal descriptive would be creamy and lush. However, my only reservation would be the slight thinning in the mid to high midrange although, with this said, lead guitars still come across in an agreeable sort of way along with male and female vocals cutting the mix well. In terms of the transient response the low midrange is, again, similar to the bass attack and decay which drastically contrasts the snappier, much higher, high-midrange response. This difference in presentation beautifully pedestals vocal tones and helps to define the spoken, and performed, word amongst complex instrumentation; in particular distorted electric guitar. Furthermore I could not detect any tight frequency bunching throughout the midrange, likewise it was free of distortion and all tonal characteristics came across clear, defined, slightly warm, without any muddiness whatsoever. With this said we can move onto the midrange soundstage and the 8.0’s have a very organic presence about them with no far thrown frequencies. To put this into perspective it’s best to describe the 8.0’s as having a natural venue stage presence with no overly limited vertical and horizontal spatial awareness. The stage on average feels great and the distinctions between instrument placement are very clear and distinct. I do have to say that very occasionally I feel as if the 8.0’s iron over some of the micro details that you would normally experience with a more analytical IEM, but otherwise the midrange is very fun, forgivable, and certainly not stuffed with air.
As we now focus on the treble frequency spectrum it has to be said that, post burn in, the 8.0 extends well and has excellent focus. You can’t say that the treble is bright, it is just there in the right doses. In fact the transient response in this area is much sharper than the bass or low midrange performance, yet the 8.0 never ever becomes sibilant and it manages to vertically position itself a little behind the aforementioned frequencies. In terms of the lateral dimensions, the 8.0’s presentation extends further afield than the low or midrange ever does. Thankfully, before the crystalline clarity gets ridiculous, Heir have tapered the super high frequency extension so that it doesn’t impact on the luscious low and low midrange, thus favouring the darker sound signature. This probably sounds confusing but, don’t get me wrong, the multifaceted nature of this IEM is magical by never making any instrumentation indistinct. Purely the sound signature is there for taste because you can hear every single layer, macro and micro. Simply put, the 8.0 makes no sacrifices, it is what it is; a work of art.
In use the Heir 8.0’s have a very low, whisper quiet, distortion free noise floor. Most notably micro details are accurately presented amongst vast patches of stereoscopic silence. In particular the use of thin ultra high frequency instrumentation cuts through a sparse soundstage with a sort of rounded elegance. Considering that this is, typically, a very cramped bandwidth area the Heir 8.0 decodes the layers with silky elegance and never allows for anything to feel too tight, sharp, and bunched up.
Although the Heir Audio 8.0 IEM performs admirably across a broad range of genres, I have discovered that they have a particular fondness for rock and acoustic genres. The 8.0’s just have a stage presence that pedestals these genres and creates an outrageously enjoyable experience that can can extend for hours at a time without any qualms.
The Heir Audio 8.0 is the epitome of relaxation and brings an highly comfortable musical experience to the ears without demanding any active attention from the listener. Granted the 8.0 IEMs hang firmly towards the dark side, but they offer a multifaceted performance that manages to retain all of the original detail. Overall The Pro Audio Web Blog awards the Heir Audio 8.0 IEM’s with four and a half stars and, of course, our Outstanding award.
Edd Harris