audio-sound @ hatena

An audio review & news blog. The volume should not exceed 80 dB is recommended. I usually adhere to the safe-listening style by WHO. Please note that my aural impressions and interpretations of measurements are also made from a safe-listening style.

(Eartip Review) LIZER LAB JIJUJET-2: Eartips expected to improve resolution. However, it is for advanced users. JIJUFIN recommended for beginners.






  • This review is based on a sample provided by LIZERLAB to convey a sincere quality review to our readers.
  • No remuneration or compensation, such as a manuscript fee, has been received for publishing this, and it is an honest evaluation based on measurement data from personal testing and personal opinion.
  • Please read the privacy policy of this website.


  • People who want to bring the midrange of their earphones more to the forefront.
  • People who want to improve the resolution of their earphones.
  • People who want to improve the reproducibility of the stereoscopic effect of their earphones.
  • People who want to make the sound of earphones brighter
  • People who want to reduce the low frequency range of the earphone



This review will give an overview of LIZER LAB JIJUJET-2. A complete review of this product can be found here.



LIZER LAB has produced and launched the JIJU out-of-head localization eartips in 2019 with the aim of solving the problem of in-head localization in earphones.


By incorporating a phase plug into the inverted cup, the cup is designed to have a reverberating effect and provide anti-vibration measures. At the same time, a small hole near the auricle, which is said to control the directional sense of sound, emits and reflects a small amount of sound to improve sound quality, including out-of-head localization, a sense of presence, localization, and noise reduction.



The improved "JIJUJET-2", the second crowdfunding project on Makuake, is now available in a new natural color for the cup part and is lighter in weight with a larger aperture diameter and reduced overall length of the phase plug, providing a better listening experience than ever before. We have also strengthened the prevention of interference with the earphone stem and contact between the ear canal and the plug. In addition, the aperture area of the sound path has been enlarged while the overall size has been reduced. (The plug has been shortened by approximately 0.8mm in overall length compared to the current model.)




JIJU is packaged in a fairly solid case.


Package contents

There is no shortage of accessories. The package contains the following:

  • Charging case
  • Manual






Mounting example



Sound quality

Sound quality description

The following changes can be expected when JIJUJET-2 earpieces are replaced with standard earpieces.


  • More midrange sound balance
  • Significant improvement in resolution


The following is a step-by-step explanation.


Please see here for detailed reviews on sound quality.


Make the sound balance closer to the midrange

Below are data measured using OpenAudio Mercury. Blue is the standard earpiece and red is JIJUJET-2.




In general, the use of JIJUJET-2 reduces the depth and volume of the low frequencies and increases the relative presence of the mid and high frequencies. The increase in presence is more pronounced in the midrange, so it can be expected that JIJU will produce a change in sound quality that emphasizes the midrange in many earphones. Overall, you can expect the earphones to change the sound in a brighter direction.


Significant improvement in resolution

Due to its construction, JIJUJET-2 increases direct and reflected sound, resulting in an improvement in musical intelligibility. This is generally perceived as an increase in resolution. For example, using Open Audio Mercury, a 15% improvement in musical intelligibility (C80) was observed. With increased resolution, the three-dimensionality of a song is better reproduced, resulting in a more holographic sound experience.


Improvement of music intelligibility (C80) by LIZER LAB JIJUJET-2, blue: with standard earpieces, red: with JIJUJET-2

Improvement of music intelligibility (C80) by LIZER LAB JIJUJET-2, blue: with standard earpieces, red: with JIJUJET-2


Sound quality disadvantages of using JIJUJET-2

JIJUJET-2 changes the sound balance quite drastically, so in general, the better the earphones are tuned for a good sound balance, the worse the balance will be when JIJUJET-2 is used. In particular, the effect on the clarity of the high frequency range and the texture of the mid-range is significant, and the better tuned the earphones are, the more likely it is that using JIJUJET-2 will degrade detail, make the texture slightly unnatural, and change the sense of localization in a slightly ambiguous direction.


Also, as a general tendency of the JIJU series, the ultra-high frequencies are attenuated.


Sound quality general comment

JIJUJET-2 is an earpiece that is generally expected to improve music intelligibility, especially around vocals.


However, I do not believe that the JIJUJET-2 directly contributes to out-of-head localization as LIZER LAB claims (although it may indirectly). I have discussed this in detail in previous reviews of JIJUFIN and JIJUJET, so I will not repeat it here.


In general, JIJUJET-2 is recommended for use with earphones that have a strong low-frequency range, especially in the heavy bass range. It is also better to use it with earphones that tend to emphasize the sense of detail. In other words, we can guess that JIJET-2 is best used with earphones that tend to have a V-shape, which is closer to low frequencies.


For most people, I would personally recommend the JIJUFIN over the JIJUJET-2, as the JIJUFIN, unlike the JIJUJET series, offers more resolution, but with much less low-frequency attenuation, so the overall sound balance is less affected.


Sound quality features

  • Improved resolution
  • Improved focus in the midrange
  • More holographic imaging


  • Significant low-frequency attenuation
  • Attenuation of ultra-high frequencies
  • Deterioration of detail
  • Deterioration of overall range


General comment

LIZER LAB JIJUJET-2 is an interesting audio item. It can be expected to have a positive effect in terms of actual resolution under the right conditions of use. However, as with any product, there are aspects that can have a negative effect.


Unlike re-cabling, which can have little or no effect, the JIJU series can actually bring about a significant change in sound quality to your earphones. In that sense, buying JIJU is a much better investment for the audiophile than buying a re-cable product that has no evidence to back it up.


However, the JIJU series is more like a high-risk, high-return financial product that, if used properly, will bring you closer to the ideal sound, but if you do not understand its characteristics, the sound may deteriorate. In other words, it is an item for advanced portable audio users who understand the frequency characteristics of the earphones they are using and have enough audio knowledge to select audio items based on this understanding, and who also utilize an equalizer and other tools to examine the sound to their liking from all angles in pursuit of their ideal sound. This is a type of product whose performance can be fully demonstrated only when used by an expert audio enthusiast who has sufficient audio knowledge to be able to select an audio item with the understanding of its frequency characteristics, etc., while actually assuming it.


Of course, I do not deny that you can buy this product just to enjoy the sound change. However, as an introductory product for trying out the JIJU series for the first time, JIJUFIN is a safer investment with lower risk and almost equal returns, so I personally recommend that you choose that as the first JIJU you buy.


Tranya F4