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HE100 Development Story

Updated: Sep 27, 2019



There have been huge changes in various industries including the audio field in an era of smartphones. These days, most people are listening to music by streaming on smartphones. Moreover, a smartphone performs as a very good source device supporting various external interfaces such as USB and Bluetooth.


Radsone is a smartphone audio company established in 2011. With our vision to provide ‘High Quality Sound to Everyone’, we provide audio products for smartphones under our brand ‘EarStudio’.


High-Resolution Bluetooth receiver ES100 is our flagship product which is consistently ranked in the top three of Amazon’s Headphone Amp section with an average of 4.4 star ratings and over 450 reviews.


After testing more than 20 earphones under $200, we realized that sound quality is not good enough and there are quite some distortions even in many famous models. Digital music file, player and DAC are all important, but the overall sound quality highly depends on earphones which converts electrical signals to sound waves. Even if the smartphone and receiver deliver high-quality sound, if the performance is not combined properly to the earphones or headphones, it won’t work as nicely as intended.


We felt the necessity of developing our own earphones and started to prepare to launch them since 2017.


Collaboration with Sonicast

Good technology can sometimes work better through collaboration. That’s the case with EarStudio HE100. We have competitiveness in making portable audio electronics but needed to collaborate with a specialist to develop earphones.


Jay, CEO of Radsone has long been friends with Dr. Shin-yul Lee, CTO of Sonicast and an international figure in acoustics. Dr. Lee is an expert with theoretical and practical experiences in the headphone driver R&D for more than a decade. He also launched Dirac earphones with his own SF driver. The SF driver is a uniquely designed driver that is acoustically well-received by Dr. Sean Olive, acoustic researcher at Harman.


When we first encountered Sonicast’s dynamic driver, we knew instantly it was outstanding. With Sonicast on our side, we developed an improved driver to complement some aspects of Dirac earphones and applied them to HE100.


The Birth of HE100

Considering time-to-market, we used the same mold as Dirac MK2, but HE100 is certainly different from existing Dirac earphones. We are confident that the sound is pretty much upgraded.


In general, when the bass is strong, a single driver lacks detail in high frequency and if the high is highlighted, the bass becomes weak. The driver inside HE100 is a single dynamic driver suitable for Hi-Fi sound quality that reproduces full range of frequency with good balance.


HE100 driver unit has unique 3 layer diaphragm that delivers steady responsiveness across the whole frequency range. It also rolls free even in extended high frequency which is the best for High-resolution sound. For example, its special open-high characteristics in listening High-resolution sound sources can easily be found when using HE100 with ES100 as 990kbps LDAC setting.

HE100 Driver Unit

In the early stage of development, we considered making short cord earphones for ES100, but the sound quality of HE100 was much better than expected. Therefore, we released them with a normal cable length. Many professional reviewers compliment HE100’s balanced, detailed sound and imaging.


With the missing analogue jacks on smartphones, the combination of ES100 and HE100 will be the best sound quality option for you.


Learn more on HE100 at https://www.radsone.com/he100

HE100 was released just a month ago, but so many users are already satisfied with their performance. We are excited to share some of their comments.


"Once these tiny earphones are placed inside my gigantic ears, the world just seems to melt away"

- Major Hifi


"Very well refined"

- Z Reviews


"I'm so impressed that I will be using the HE100 as my new daily driver with the ES100"

- @Reebonz, Head-fi User


“My first feeling about the sound was that it's pleasantly effortless. Whatever I threw at it, it sounds like it's no big deal. There's excellent clarity in low volumes”.

- @Tadeas, Head-fi User


“A very clean presentation, nothing bleeds into anything else, but there is still enough detail and oomph. Very impressive indeed.”

- @nightrook, Reddit User


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