IEM Review

The reveal of the limited edition JIMI from Jerry Harvey’s AION series was one of my first articles here on Major HiFi, and now I finally get to review them for you. Jerry Havey is a celebrated brand known for its universal fit IEMs. The Roxane from their performance series made waves across the board for their massive 12 driver system and crystal clear output. Now Jerry Harvey has released a limited edition IEM to their prestige catalog, the JIMI from the AION series. Can the JIMI AION keep up with Jerry Harvey’s illustrious reputation?

IEM Box contents

What You Get

The JIMI AION comes with a few notable accessories to touch on. The IEMs themselves are located in Jerry Harvey’s signature rounded metallic case, which is always a nice piece of memorabilia. A variety of ear tips are also included, with your choice between 3 sizes of silicone tips and 3 sizes of foam tips. In the boxes tiny side pockets, there are two tools, one for wax cleaning and a tiny screwdriver for the bass adjustment controller.

IEM Shell

Look and Feel

The Jerry Harvey biker aesthetic has always been an original take for an IEM and considering how they’ve designed their main sound output around it makes Jerry Havey a brand to look out for. The JIMI AION features a striking, custom made housing, with a colorful, glossy, wooden finish. The faceplate sports a golden version of Jerry Harvey’s angel logo with inlay colors of blue and green, all shaped in a guitar pick like architecture. These are some of the most stylish IEMs around, and my eyes lit up when I first unscrewed the metallic case to reveal them. However, there is the matter of how they fit, and I was a little underwhelmed in that aspect. The JIMI AION fits fine for the most part, but I found the nozzle to be a little too wide and created a stretched out feeling in my ear canal. It takes time to break-in and after a few long listening sessions, but even then I started to take them out and readjust them multiple times. I strongly suggest using foam ear tips with the JIMI AION, as the large nozzle will be less intrusive.

IEM Design


I want to make a note on the brand new custom cable the JIMI AION comes with. This guy is a beast. It’s a thick, black 7 pin Litz wire cable, made from military-grade iridium. This cable is designed to withstand harsh environments, and will surely never fray. The most interesting part about this cable, and one of the JIMI AIONs’ most significant features, is its bass filter located at the far end of the cable. You use the tiny screwdriver to fine-tune the gain of the left and right bass signals which you can adjust from 0 to 12dB. 

Packed inside this immense housing is a 7 driver configuration powered by SounddrIVe technology. Much like most of this IEMs design, the JIMI AION’s drivers are custom made balanced armatures, with dual lows, single mid, and quad highs. All of these components are housed in a 3D printed acoustical sound chamber that uses a recessed tubing system that blocks out dirt and sweat. With all of these peripherals, the size of these earpieces makes a lot more sense. 

IEM Attached


I don’t mean to sound like a Karen but there should be a safety warning with on the box of the JIMI AION. These IEMs put out a powerful signal that can be surprising when using the 3.5 connectors to jack into a computer or smartphone. Default high gains are dangerous for the JIMI AION as they only have 17 Ohms of impedance, with a sensitivity of 117dB/mW. You won’t need an amp to drive these guys at all. The JIMI AION also offers a wide range of frequency information, with a response of 10Hz-23kHz.


What I’ve been hearing from the JIMI AION isn’t anything substantial, but still impressive. The stage does a great job of making specific tracks sound big, like big rock sounds, pounding tympani, and pulsating synth tracks. Drum sections on rock tracks also sound much greater on the JIMI AION bringing out a fuller space. While separation and spatial imaging feel accurate and clear, instrumental sections get to take their place in the sound field with proper resolution. 

Low End 

If it wasn’t for the JIMI AIONs bass control system, I would say that this low end is lacking, but even with this feature, I wouldn’t consider this a bass heads IEM. Without bass control, the JIMI AION sports a limited low-end response, but craking them up reveals a deep resonance that adds a little edge to your tracks. The sub-bass is present, but subtle, and expands with a natural smoothness. This easy-going tonality works great on tracks like “Walk on the Wild Side” from Lou Reed, where the main bass riff comes out crisp. Other hard rock track or pop-punk ballads like “Shoulder to the Wheel” from Saves the Day lifts the explosive electric guitar intro to a satisfying power that makes you feel energized. The bass response may be lacking in tracks that require thickness or punch, but it does do a good job adding a sharp bump to others. 


To say that the mids sound big would be an understatement, they’re massive! With the JIMI AION, you get a full spectrum of mid-range tones that bump the amplitude to a grand degree. The distribution of loudness is balanced in the mids and specific elements show off greater details and character. Vocal performance clarity is crisp and forward and brings out a number of qualities in production. Max Bemis’s vocal work on the track “A Walk Through Hell” by Say Anything makes light of the intimate rendition while balancing the harmonies to a delightful crescendo. Distortion on electric guitars also takes on a crunchy, crackly quality that makes punk tracks feel more energetic and edgy. For instance, the track “Free At Last” from PUP  features grimy distorted guitars that offer a more sufficient edge on the JIMI AION. 


Certain sonic elements work in conjunction with the highs, creating a fleshed-out signature that has detail and spaciousness. Hi-hats and crash cymbals resonate in the mix with sparkle and clarity. They’ll sound somewhat weaker compared to the mids, but like the lows, they add a little spice to the mix that pushes the signature to its limit. 


The JIMI AION might be hard to come by, but if you love rock and roll, and are looking for a high-end IEM to produce those grimy electrics and pounding drums, these earphones might be for you if you’re willing to dish out the $1699. However, if comfort is really important to you, there might be some better options. 

Pros and Cons

Pros: Meaty mid-range, pleasing aesthetic, bass control 

Cons: Comfort, Price 

JIMI AION available from Audio 46

MAJORHIFI may get a commission from retail offers.       

Discuss this, and much more, over on our forum.

MAJORHIFI may receive commissions from retail offers.