64 Audio Aspire 4

Introduction to the 64 Audio Aspire 4 Review

64 Audio is a brand mostly known for its professional, stage-oriented heritage. That, and of course their numerous successful releases, like the explosive Tia Trio, beloved U12t, or one of the more recent releases, the Volur. Well, the Aspire 4 is the latest among 64’s catalog, so I guess it’s fair to ask yourself – is it a product for the stage, or for the everyday audiophile? Here is where opinions may differ, as the 64 Audio Aspire 4 seems to check some boxes in both of those categories. 

This may leave some confused, flabbergasted, perplexed even. But if there’s one thing that you can be sure of, is that the guys at 64 Audio know what they’re doing. The Aspire 4 is a 4-driver construction – a single dynamic driver handles the low end, two balanced armatures take care of the mids, and another balanced armature is responsible for the top end. This 1DD+3BA configuration is going to set you back 899 USD, and, most importantly, is available only as a universal model (UIEM). 

If you care to visit the product page for the reviewed 64 Audio Aspire 4, its makers seem to suggest that it is a product supposed to fit an extremely specific niche – it’s meant either for those starting off with in-ear monitors, and/or for those not-so-enthusiastic towards custom-fitting IEMs. Either that or the Aspire 4 can be considered a backup piece of gear. That’s quite an outlandish statement considering it’s 900 dollars! On the one hand, that’s a lot of money for a “backup” product, but on the other, we’re talking pro audio here.

If anything happens to your main pair and you’re supposed to hit the stage in 15 minutes, a backup pair of Aspire 4’s quality is a godsend. Trust me, I know what the thrill of a great vocal performance is all about. I sing in the shower regularly and I know how it feels to nail that high-pitched note in “Dream On” by Aerosmith. Or at least I hope so… Anyway, Aspire 4 has to be the most pro-audio-oriented product I have reviewed to date. That’s why some aspects of it are going to seem familiar, and others not so much – expect a mix between professional heritage and audiophile-friendly performance within this pair. 

Packaging

The unboxing experience of the reviewed 64 Audio Aspire 4 is pretty basic. You get only the things that are most necessary, each of them without extra flash, colors, or flamboyance. It’s supposed to be a sleek pair of IEMs, and that extends to the accessories as well. Within the box of the 64 Audio Aspire 4 lies a small square carrying case with a zipper and a large 64 Audio logo making sure you don’t confuse it for anything else. It’s pretty basic but raises no safety concerns. You also get a 48-inch braided cable of astounding thinness. 

I guess it’s the first pro-audio aspect of the pair that jumps out at you – it’s nothing like the thick, ultra-premium audiophile IEM cables, as it is supposed to serve a different purpose – staying out the way. You can easily run this through the back of your shirt and totally forget that it’s a wired IEM, and that’s the best thing about it. If, however, you’re after a more premium experience, don’t expect to be blown away. It also has no splitter, just a clear piece of heat shrink. 

I’ve got a bone to pick with the cable, and surprisingly it doesn’t have anything to do with ergonomics. It’s the IPX connectors. Undeniably, IPX connectors have their advantages – they are way more compact than something like an MMCX or a 2-pin, they are sturdy and geared towards being long-lasting and wear-resistant, and most importantly – they are designed to meet higher water resistance standards, protecting the connectors from the artist’s excessive sweat during a lively performance. 

So why am I not a fan? Well, it has to do with the rarity of the IPX connector among other IEM pairs. Every pair I own sports a 2-pin connector, with some others like Campfire Audio opting for an MMCX. Finding a cable with those is quite easy, meanwhile, I don’t recall seeing IPX cables nearly as often. If you have no issue with shelling out some bucks for a custom cable, then simply enjoy a very practical and sleek connector. Apart from the cable I just wrote a small litany on, there is also a plethora of tips – 12 pairs to be exact, 4 types, 3 sizes, silicon and foam – and a cleaning tool, which is something I greatly appreciate in my IEM package.

Design, Build Quality and Tech

The build quality of the 64 Audio Aspire 4 is quite different from what you might come to expect from 64 Audio, especially if pairs like the U12t are what you’re familiar with. You may be more used to a metal construction – well, this time around, it’s ABS plastic. Like many things in life, it comes with its pros and cons. ABS never gives off a “cold” sensation that some metal IEMs may exert, and it is a great choice of material for a lightweight yet sturdy construction. And so it is in practice – the Aspire 4 feels noticeably light. However, ABS doesn’t provide the most premium experience that one may expect from a metal or resin IEM at this price point. 

The craftsmanship, however, leaves nothing to be desired. Every piece is fitted with no irregularities, loose bits or sharp corners. And good fitment here is crucial, if you want your IPX connectors’ waterproofing to be useful. I don’t plan on submerging my IEMs in any liquid to test that, but I’m pretty sure that if you wear those in a hot and humid environment, leakage and subsequent malfunction should not worry you. 

One of the Aspire 4’s main selling points according to the manufacturer is the ergonomics. It’s supposed to be a comfortable IEM with a shape that’s appealing to the masses, and it’s precisely what it is. I like the combination of the lightweight construction and skin-friendly materials used. The guys at 64 Audio did a good job at designing an IEM shape that is going to fit most ears well, providing an almost disappearing sensation, as prolonged listening sessions with the Aspire 4 are comfortable. I don’t get any hotspots on any parts of my ear, and the lightweight nature of both the IEM itself and the cable really shines when taking them on a longer walk or choosing to spend the evening relaxing with some music. Another aspect I like are the tips – the selection and variety show mass appeal in mind, and that’s precisely what has been achieved. With 4 different eartip types, each at 3 sizes, it’s hard not to find something for yourself. Great job! 

The tech is surely one of the more interesting aspects of this 900 USD construction. The manufacturer notes four specific technological advancements being used in the tested 64 Audio Aspire 4 – the stainless steel nozzle, Apex core, Waveguide and LID. The stainless steel nozzle is precisely what the name may suggest – this feature is supposed to increase durability in the face of consistent use and switching of the eartips. 

The Apex core is an especially interesting technology involving a discrete pressure release system, using a special channel, supposed to control the amount of sound being leaked. I’m particularly fond of this feature, as it provides a vast soundstage while maintaining decent acoustic isolation. The Waveguide is a structure that’s supposed to increase the efficiency of the high-frequency balanced armature driver by “focusing” the sound. The final piece of tech utilized within the Aspire 4 is LID, which is a module helping correct the impedance of the drivers, maintaining their linearity. 

Sound of the reviewed 64 Audio Aspire 4

The sonic performance of the 64 Audio Aspire 4 is where the pair bridges the gap between ultra high performance pro audio usage and a more laid-back, audiophile use case. The sound is balanced with a boost to overall clarity, with the bass being ever so slightly more pronounced than the rest of the frequency range. Apart from that, I don’t hear any specific parts of the sound signature jump the gun too much, so I think it’s fair to assess that the IEM leans more towards a true-to-the-original, neutral sound signature, with no extra coloration or thick warmth. Neutral-sounding gear is a dangerous territory, where lots of gear falls short on the excitement factor, sacrificing raw listening enjoyment for the sake of pure neutrality. I am not a fan of that, and I am happy to report that that is not the case with the Aspire 4. The sound is dynamic and large without the special effects being overdone, so listeners putting an emphasis on naturality of the sound can remain at ease. 

BASS

Clarity is perhaps the most standout feature of the bass, accentuated by fast attack and decay of the lower notes. Tracks like “Breathe In” by none other than Pink Floyd employ a calm bass guitar passage with the percussion providing the pacing for the whole spectacle, and everything seems to be well in line. Artifacts, like the bass melting over other frequencies, seem to be the least of the listener’s worries. Despite there being a decisive presence of the bass no matter the genre, the Aspire 4 maintains a tidy presentation throughout the listening session. The amount of bass seems to be just enough to keep the sound signature versatile for basically any music genre you throw at it. There is a pleasant tactile sensation in the reproduction of instruments like kick drums, but the tactility is rather light, employing a pleasant sharpness and decisiveness. 

However, personally, I wish that there was a bit of a boost to the lowest of the lows, as in some cases I am left desiring a more powerful subbass rumble. That being said, I appreciate the fact that the technical aspects of the bass have been refined to such a level, and while it’s not 100% of the way there for me, it’s still a great execution of a more neutral sound signature. Within tracks like “Offshore” by the Polish duo TEKTONIKA and HAZE1 I am used to a more aggressive bassline, and here it’s more tame, adhering to the neutrality befitting a product intended for professional use. The bass is present, decisive and cooperative with the rest of the sound signature, knowing its place in the sonic realm. 

MIDRANGE

The midrange of the reviewed 64 Audio Aspire 4 is where the neutrality prevails the most, as the mids don’t display any sort of coloration or boost to the richness of the presentation. As was the case with the bass, its strongest suit is precision, clarity and detail, all presented on a natural, albeit sometimes slightly dry background. If you’re the target audience for this IEM as determined by the manufacturer – someone who’s just getting started within the IEM world – this is the kind of sound that makes you go: “wow, I hear sounds I haven’t heard before”! It’s clear that the intention of 64 Audio was to put all the points into reference-like qualities with a superb technical performance, instead of making an explosive, flamboyant IEM. And so they did, making the music sound interesting, curious even, inviting the user to do some analytical listening of their usual favorites. 

Choosing between upper and lower midrange, I would say that the former definitely has the advantage of being slightly more prominent. I would attribute that fact to slightly lesser prominence of texture reproduction of the bass, with a certain sparkle and energy of the highs that I’m going to describe soon. I also consider the highs to be more dynamic than the lows in this IEM’s sound signature, and the midrange reproduction here seems to be a marriage of both – neutrality maintained, with a more rounded and tame lower mids, and more lively upper mids. I like that about the 64 Audio Aspire 4, and I consider it one of its stronger points, even if sometimes I would wish for a more lush and colorful presentation. The Aspire 4 does a great job at what it’s been designed for – being a powerful tool for anyone needing clarity and detail with tasteful neutrality. 

TREBLE

The treble is something I enjoy quite a lot about the 64 Audio Aspire 4, with the main attraction being the dynamics. Listening to Kanye West’s final instrumental sequences on “Hold My Liquor”, the high-pitched grind-like sounds seem to dance on the expansive soundstage, accentuated by the dynamic treble reproduction. It’s fun and seemingly effortless, bringing life into the presentation. These highs might make you appreciate the tamed lows, seeing how many IEM’s get that wrong – a boomy, wannabe-fun bass reproduction can sink the whole ship, not leaving the treble any space to shine. Personally, I much prefer a signature like this, where there is overall balance to be heard, with an extra serving of liveliness thanks to the treble’s pleasant dynamics. 

The treble doesn’t shine just in the lively recordings, as its technical prowess can also be appreciated during the calmer passages, like in “Eyes Without a Face” by Billy Idol. This mellow, romantic track gets its flowy pacing from the hi-hats and claps, and in this instance, their energy ties in well with a more laid-back piece of music. This highlights the signature’s versatility – it can increase the energy of certain tracks, while at the same time providing accurate results. The treble’s balance is also highlighted in the fact that there is absolutely no sibilance or hotness to the treble to be experienced. I guess that’s the Waveguide module hard at work. Overall, the treble ties in well with other aspects of the sound in creating an accurate and insightful yet lively presentation, fitting both professional use and casual listening sessions. 

SOUNDSTAGE

Together with the treble, staging is my favorite sonic aspect of tested Aspire 4 by 64 Audio. The staging is absolutely vast, with its potential increased thanks to the Apex core system. An effective pressure relief system provides a huge enlargement to the soundstage, with its size getting close to that of decently-staging open-back headphones. It’s quite a feat considering the differences in size of both the driver and the devices themselves. It seems that there’s been an influx of IEMs with immense staging capabilities, and I can honestly say that in terms of staging performance, 64 Audio Aspire 4 doesn’t perform worse than its twice-as-expensive competition. 

I am of the opinion that no soundstage can truly spread its wings without proper imaging. I am glad to report that this deadly combination has been achieved in the case of the Aspire 4. The immense clarity and detail of bass, mids and treble results in very clear imaging of the sources of sound, with the listener being easily able to pinpoint their seemingly exact location on the soundstage. This makes the reviewed 64 Audio Aspire 4 a useful tool not only for mixing and mastering your music, but for gaming as well! If you’re someone who relies on audible cues for pinpointing the location of the enemy in first-person-shooters, the Aspire 4 will surely help you finally raise that K/D ratio above 1.

Pairings

Reviewed 64 Audio Aspire 4 is not very picky in terms of amplifier and DAC pairings. As long as you have something more powerful than the Apple dongle, that doesn’t output noise like crazy, you’re going to be satisfied. That being said, I have tried a few different pairings, the Apple dongle was first. It sounded okay. That’s all I have to say about this. If you can’t obtain a better DAC to save your life, the Aspire 4 will perform decently, but don’t expect fireworks, and bear in mind that it deserves something better… 

Like the Luxury&Precision W2. This slightly aged but still powerful dongle is my daily driver when testing IEMs thanks to its precise sound and plenty of power on tap. Something neutral yet dynamic like that is a perfect fit for the Aspire 4, as it highlights its faithfulness while also breathing a certain amount of life into it by uplifting the dynamics. I have also done some listening on the Cayin N3Ultra, testing out the solid-state mode and both the tube modes. I was expecting to enjoy the Modern Tube preset the most, as I usually do, but this time the solid-state mode fit the IEMs the best, highlighting their capabilities.

Comparisons

HiFiMAN Svanar

Even though the Svanar is more than twice as expensive as the 64 Audio Aspire 4, I still consider it a fair comparison due to both contenders showing an immense level of staging and imaging. While the Svanar remains my favorite IEM so far, there are aspects of the sound where the Aspire 4 gets dangerously close – technical aspects like detail, treble dynamics don’t leave much to be desired. That makes me consider the reviewed 64 Audio Aspire 4 a product punching way above its price category in terms of raw performance, giving more expensive IEMs I’ve tested a run for their money.

64 Audio Aspire 4 Review – Summary

64 Audio Aspire 4 remains the most professional piece of equipment I’ve reviewed so far and I’m glad to have taken a look at this particular niche. This 899 USD 1DD+3BA UIEM represents some great value for money in terms of sonic performance, but how much you appreciate those is going to depend on your approach towards professional IEMs and your personal use case. 

The Aspire 4 is an IEM that is minimal in aspects like packaging, accessories and build materials, but upon your first listening session it becomes clear that all of the resources have been spent towards tuning this IEM to be a great neutral-yet-natural contender in the sub-1k USD range. If professional audio is your thing, or you simply like a neutral sound signature, while looking for some liveliness and sparkle in the highs, your search for a new IEM may be over. 

Recommended.