Review: Astell&Kern Billie Jean – The One

Astell&Kern Billie Jean

Disclaimer: The Billie Jean by Astell&Kern was sent to me free of charge for this review. It does not have to be returned. Astell&Kern is not affiliated with Headfonia and not a site advertiser. Many thanks for the generosity and opportunity!

About Astell&Kern:

Astell&Kern is a South Korean high end brand for digital audio players (DAPs). Astell&Kern is a branch of Korea’s iRiver, which actually is the first company to ever build a portable audio player. Astell&Kern was launched with the mission to offer the absolute best where money is no object. Ever since their launch, they have redefined what is possible from portable devices. With the AK100 they introduced their first product in 2013 under the A&K brand.

Astell&Kern has pioneered a few things we know of today. They were the first to build a DAP with two DAC chips inside – AK120. AK was the first brand ever to introduce native DSD playback in a portable device – AK240. The AK380 was the first ever digital audio player that came with a Parametric Equalizer.

Just recently AK has introduced what they call Teraton. This is an audio module that contains their digital and analogue design. This module can be implemented by third party brands in order to get closer to the AK sound. The first product has already been released that utilizes Teraton – the Activo CT10.

AK also cooperates with many other industry leading brands. In partnership with brands like Beyerdynamic, Final Audio, Jerry Harvey Audio or Crystal Cable, Astell&kern has brought out many different products under their name. Together with JH Audio they have released a good number of different universal In Ear Monitors. The most recent being today’s review’s guest of honour – the Billie Jean.

About Billie Jean:

The Billie Jean is a dual BA monitor that uses a single BA for bass/mids and a single BA for highs. It is part of the Siren Series by Jerry Harvey Audio, under which also products such as the Angie or Layla have been introduced. Billie Jean also features the patent pending Freqphase Time | Phase Wave Guide. Which is said to cancel out any phase inconsistencies for a more harmonic sound. Here’s a video of Jerry Harvey explaining it in more detail:

The Billie Jean is also the first JH Audio product to come with an acoustic chamber introduced in the nozzle. This chamber is located after the opening of the sound bores and offers a small chamber for the sound to be optimized.

Billie Jean is available in two colours, red and blue. It’s impedance is measured at 18 Ohms, there is no information about frequency response or sensitivity. Though I must say, that the Billie Jean to me seems like a rather sensitive monitor, as it is fairly easy to drive to loud listening levels (not advised of course). It also picks up noticeable noise from my Chord Hugo2.

Billie Jean is available for 349$ at your local Astell&Kern shop. If there’s none in your country, you may consult Astell&Kern’s online shop.

Here is another video by Jerry Harvey where he discusses the birth of Billie Jean:

The review continues on page 2!

4.4/5 - (195 votes)

A daytime code monkey with a passion for audio and his kids, Linus tends to look at gear with a technical approach, trying to understand why certain things sound the way they do. When there is no music around, Linus goes the extra mile and annoys the hell out of his colleagues with low level beatboxing.


  • Reply August 14, 2018

    Andrew Candeloro

    How would these be next the oriolus forsteni in terms of sound signature? Im leaning towards the forsteni but am scared of all the comments saying they are too hot sounding.

    • Reply August 15, 2018


      Hi Andrew,

      thanks for your comment.

      Sadly I have never heard the Forsteni myself. If you have the chance to audition Billie Jean or the Oriolus, it would be best to do that. I know people can be very sensitive to treble, and I said it in the review that Billie Jean might be too much for some. So you really should give it a demo if you’re concerned about it. I’m fine with it, but that doesn’t mean you are…


  • Reply August 17, 2018


    I originally planed to buy a pair of Westone UM 30 pro but my local shop stop selling them. I tries these out to see if they would fit my taste. I like what I hear except for the mid. I find the mid range, especially the vocal, to sound unnaturally thin in comparation to other iems i tried that day.

    Can you suggest other iem in the same price range with similar sound signature but fuller mid range? Thank you!

    • Reply August 21, 2018


      Hi Srs,

      I truly wish I could help you, but unfortunately I can’t. I know Berkhan is a fan of the Oriolus Forsteni, which has a similar price and might suit your taste. Though I’m not sure if it still is available.

      • Reply August 24, 2018

        Andrew Candeloro

        I’ve contacted oriolus and they said by end of August they should be available.

  • Reply November 14, 2018

    Sagar Shah

    Can you compare A&K billie jean with Etymotic ER4XR?

    • Reply November 14, 2018


      Hi Sagar,

      thanks for your comment.
      Sadly I can’t, as I haven’t heard this one, sorry.

  • Reply February 12, 2019

    Sandro Mosca

    How does the Billie Jean compare to the Weatone UM 50 Pro?

    • Reply February 14, 2019


      Hi Sandro,
      thanks for stopping by and leaving a comment.
      Unfortunately I can’t help you there, as I haven’t heard the UM 50 Pro, sorry.

  • Reply December 30, 2019


    Can you reply me with a comprison with billiejean and rha t20i

    • Reply December 30, 2019


      Hi Syam,
      I wish I could, but I haven’t heard the T20i ever. Also, I only do comparisons to models I have heard extensively and have at home. Anything else wouldn’t be reliable in my opinion. Hope you understand.
      Have a great 2020!

  • Reply January 11, 2020


    Hi Linus, just ordered a Billie Jean because of your review 😉

    Just curious, have you ever tried the AK Michelle Limited? I’m curious how it compares to the newer and cheaper Billie Jean.


  • Reply September 15, 2020


    can you compare the Billie jeans with the thieaudio L3 or the bgvp dm6 or fiio fh3

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