64 Audio Aspire 4 resting on a wooden stool

A Little Something for Everyone | 64 Audio Aspire 4 Review

Finding an IEM that meets all your personal needs is as good as striking gold within this hobby. While many IEMs are marketed as delivering an experience that meets the mark for a variety of listeners is common, one that actually delivers said promises is not. Aspire 4 aims to deliver an all in one experience that appeases the tastes and needs of audiophiles, musicians, and even gamers. However, doing that well or not will decide whether it's truly the all in one package at $900, or merely just another stepping stone in the pursuit of finding a real do it all IEM. 

Build and Design

64 Audio has never been too elaborate with their unboxing experience, and Aspire 4 is their most bare bones yet. The included cable is an IPX cable, which is most likely to appease on stage musicians, but that is where my biggest gripe with the package resides. The cable is overly thin, tangles easily, and does not feel like it belongs on a $900 IEM. The same goes for the case, 64 Audio ditched the usual, more circular and leather IEM case that comes with IEMs like Volür and U4s, which would have been a more premium choice that could’ve gone a long way in fleshing out this unboxing experience. Instead, we get a boxier case that will primarily be thrown in a bag, and isn’t distinguishable from any other case that would house a more pro audio focused tool. Aside from those two choices, we get the standard shirt clip, 6.3mm adapter, an IEM cleaning tool, and an 64 Audio sticker. Nothing outside the ordinary for 64 Audio in terms of an unboxing experience, though I still would’ve loved to see more flare and creativity.

64 Audio Aspire 4 and all the included accessories in the box

As for the actual IEMs themselves, Aspire 4’s all black look remains low profile… aside from the rather large 64 Audio logo front and center on the IEM itself. Within the shell, 64 Audio packed 1 dynamic driver for the bass, 2 balanced armatures for the mids, and 1 balanced armature for the highs. 64 Audio has implemented their “Waveguide” technology here with the balanced armature in the highs as well. In theory, this aims to capture all the detail usually presented in their Tia driver, but in a slightly more digestible way. 64 Audio decided to stray away from their usual aluminum chassis, and opted for a lighter, ABS plastic shell. Although this mostly takes away from the premium finish that 64 Audio almost always looks to achieve, I will say that this is one of the most comfortable 64 Audio IEMs to date, and is the perfect fit for musicians on stage, gamers looking for something that can be worn in competitive matches for a long time, and of course audiophiles who simply look to listen to music for a good chunk of time. We also don’t get the usual Apex modular system here as 64 Audio most likely wanted to stick to a frequency response that they felt was natural and balanced. Similar to the unboxing experience, Aspire 4 is functionality over fun, and keeps things mostly straightforward to accommodate a multitude of different listeners with their approach to the build. However, I would’ve loved to see 64 Audio take a page out of ThieAudio’s book in their idea for the Monarch MKIII in offering multiple different faceplates for listeners to get a more creative look for their IEMs. I think this would’ve been a great way to bridge the gap further between the various listeners 64 Audio is looking to appease. 

64 Audio Aspire 4 on a wooden desk with a green plant next to it


Accuracy is a hard claim to make in audio - what truly is accurate? How can we define such a claim in such a subjective space? Well, if I had to give an example in the form of an IEM of what I define as accurate, Aspire 4 may be near the top of my list. 

In the lowend, Aspire 4 offers a bass response that helps break up the focused neutrality that this IEM presents across the board. Aspire 4 has a sharp punch in its bass that separates kick drums away from the rest of the mix, hollowing out percussive elements that some IEMs can have bleed into the lower mids. Aspire 4 never has this problem, and keeps each frequency of its sonic presentation exactly where it needs to be, further adding to the excellent separation that I will touch on later. There's a certain character to Aspire 4’s bass response that's incredibly present and rich, in what I found most notable on Tame Impalas “Borderline” track. There's such a large hit in that bass drum that should be overwhelming towards the rest of the bodies of music, but Aspire 4 keeps it tamed and at bay. 

Speaking of the midrange, Aspire 4’s overall note weight isn’t anything terribly special, but instruments and vocals do have a solid body to them. Again, that lack of congestion and separation that Aspire 4 does really well gives instruments plenty of room to shine, and the slight elevation in vocals further builds upon the idea. “Part III: Pursuance'' is not only a great display of John Coltrane’s musical genius, but also an incredible ode to Aspire 4’s ability to present a complex number of various instruments like the centered piano, vibrant percussion to the right, and the sporadic play of saxophone to the left, with sublime separation from the treble and bass, and of course with remarkable clarity to boot. The pitch black background further bolsters the exceptional demonstration of instruments in Aspire 4’s midrange, making a multitude of different genres come to life in their own unique way. 

64 Audio Aspire 4 resting on a vinyl record organizer

The treble of Aspire 4 was where I worried the most after reading up on 64 Audio’s decision to not impart their in-house developed Tia driver that I love so dearly. Early into my listening sessions, I almost couldn’t believe how well 64 Audio managed to capture their usual treble without the implementation of their Tia driver, and think this has been 64 Audio’s best combination of their usual treble detail, without getting too hot or sibilant in some S-tone deliveries. Personally, I’ve always enjoyed 64 Audio’s top end presentation, but do recognize that some can find it fatiguing in certain instances. For an example of a track that can fluster some other IEMs in the top end frequencies would be “Hit the Lights” by Metallica. The flurry of cymbal crashes, screeching vocals, and high pitched whines from the electric guitar came through clear and transparently, all while not being fatiguing in the slightest. For those waiting on 64 Audio to make an IEM without the usual spice in the top end that was portrayed in their other offerings, Aspire 4 may be for you.

To wrap things up with the sound portion, I want to tie in Aspire 4’s gaming ability as it transitions well into the sound staging, imaging, and overall technicalities as well. When playing a few casual matches of Fortnite, a far cry away from my more competitive focused days, I quickly noticed how well Aspire 4 captured directional sound. Footsteps and gunshots in the nearby distance could be followed with pinpoint accuracy, and allowed my play-style to be catered more to the advantage that I felt like I had in knowing when and where a fight was taking place. While 64 Audio’s sound stage does sound natural and precise, it is quite expansive as a whole, and offers a certain level of three dimensionality that I would expect in 64 Audio’s ultra high end offerings, not in their now entry level IEM. To further focus in on separation of instruments, Aspire 4 alleviates any feeling of congestion within the mix, and opens up the room for each instrument to have their own spotlight. This means that Jazz in particular shines mightily, and was often my go to genre of choice with Aspire 4. 

Final Thoughts 

64 Audio had a lot to accomplish with Aspire 4, and in short, they pretty much nailed everything they set out to do. If you’re strictly an audiophile like myself, who maybe enjoys light gaming on the side, you may not get the most out of these. However, placing myself in the shoes of someone like my colleagues, Marty and Steve, who have more on stage experience, an interest in gaming, and of course are audiophiles – 64 Audio Aspire 4 becomes one of the very few IEMs that really does it all, and it does it all very well. 

64 Audio Aspire 4 resting on a vinyl record on top of a wooden desk