64 Audio Aspire 4 Cover Image

64 Audio Aspire 4 Universal IEMs Review

64 Audio, a brand known for its family origins and innovation technology, has come out with a new model of in-ear monitors. The Aspire 4 Universal IEMs have a lot of updated technology that is designed for musicians, both recording and performing alike. The Aspire 4 retails at $899, so let’s dive into the details of this particular model. 

What Comes In The Box

  • Aspire 4 Monitors, with molded ABS shell and stainless steel nozzle
  • IPX Cable: 48” Black, detachable, 90˚ 3.5mm jack
  • Foam and Silicone Ear Tips
  • Carry Case
  • ¼” adapter
  • Cleaning Tool
  • Shirt Clip

Aspire 4 Box Contents

Aesthetics and Functionality

The look of the Aspire 4 monitors is a classic. The monitors themselves have an all black finish, with matte black casing and a glossy finish on the outside face. The 64 Audio logo is etched in the stainless steel to match the nozzle on the end. The in-ear fit is very comfortable, and with the 12 (yes, 12!) different ear tips to choose from, any listener can find what feels best to them. The 3.5mm jack at the end of the cable plus the ¼” adapter makes for easy plug-in to any audio hardware. 

Tech Specs

  • Frequency Response: 20Hz – 18kHz
  • Isolation: -20 dB
  • Impedance: 11Ω @ 1kHz
  • Sensitivity: 104 dB @ 1kHz @ 1mW
  • apex®core pressure relief system
  • 4 Driver Technology
    • 1 Low Dynamic Driver
    • 2 Mid-Balanced Armature Drivers
    • 1 High Balanced Armature Driver

Aspire 4 closeup

Listening Review


The soundstage for this pair is incredibly wide. I think the apex®core technology that comes into play makes the stereo image wider by giving it the chance to breathe. It is easy to get fatigued wearing IEMs for extended periods of time, but with these, it is a thing of the past. The soundstage offers a lot of balanced sound between the frequency ranges, as well as startling accuracy for instrument placement. 64 Audio makes products designed for musicians of all types, from novice to professional, and the comfortable fit and stellar imaging proves that. I will say that upon listening a lot over time, it seems that the lower range gets a boost in volume compared to the high end, but that could be due to the limited frequency response or a different design factor. It was not noticeable when listening at first, as I was just blown away by the stunning placement accuracy and noise isolation. 

Low Frequencies

Perhaps it was the selection of songs I listened to, but the Aspire 4 gave me a really rich and pumped bass tone. They deliver a bass kick with a good attack without it getting washed out. It was really punchy and jumped out in almost every song I listened to. The choice for a dynamic driver for the bass frequencies was a smart one, as it gave me just the amount of low end I needed with great clarity and warmth to boost up any song. Most notably, the song “Five Minutes” by The Altogether had an incredibly present bass that kept me hooked the entire time. Across different genres, the bass remained consistent with its tonality and presence in the tracks. 

Mid-Range Frequencies

The mid range frequencies did not disappoint. They were crisp and clear, with vocals really getting the clarity they deserve and need to be noticeable in a mix. “King of Spain” had the most memorable level of vocal detail, since a lot of the instrumentation there is replaced or accentuated by a voice. The harmonies and textures of songs thrived in the Aspire 4’s, given the two balanced armature drivers that help accentuate the mid range. There is a nice balance between the mid range and the low end, and the transition between the sections in different genres is smooth and not jarring. It is easy to fall in love with this section given how easy it was to listen to. 

High Frequencies

This is the area that has disappointed me the most. Make no mistake: the high end of the Aspire 4’s are still beautifully done. However, I find that the volume all but starts to drop off with the high end. The only way to really accentuate the high end in the way that I might want would be to EQ it manually, but the Aspire 4 does not offer that kind of adjustment; you’d need to get some outside gear for that. When the high end does come through, it has great color and provides a lot of balance for the tracks. It is crisp and detailed that makes it very pleasant to the ear. I find that this driver works overtime to really get the highs to be accentuated in a mix, but it seems to not do enough. 

Aspire 4 Closeup with Box Behind


To conclude, the Aspire 4 gives a mixed reaction. I wasn’t blown away completely, given that the high end falls short and all we are left with is bass. However, the quality of that sound is something to applaud given its sharpness and detailed delivery across various genres. My personal preference would not have me running to purchase these. Everyone’s ears are different, so I would definitely suggest giving the monitors a test-run before signing off on a purchase like this. 

The Aspire 4 Universal is available for purchase at Audio46.

About Author

Spread the love

Leave a Reply

Your email address will not be published. Required fields are marked *