Review: Astell&Kern AK T9iE


In this review we check out the Astell&Kern AK T9iE. Their latest collaboration IEM with German Beyerdynamic. It sells for $1,299USD.

Disclaimer: The Astell&Kern AK T9iE was sent to us for the purpose of a review. Astell&Kern is not affiliated with Headfonia and not a site advertiser. Many thanks for the generosity and opportunity.

About Astell&Kern:

The Korean DAP manufacturer Astell&Kern has been around since 2014 and has been since then the driving force of reinventing the portable audio player market. Ever since their first product, the AK100, they have been on a mission to make the best possible DAPs, and if you ask me, they have succeeded.

A&K is a subsidiary of the famous iRiver brand, which is now called Dreamus. The company that rose to fame with their excellent and wildly popular mp3 players. With that extensive knowledge they have launched an uber-high-end brand for the niche market that is headphone enthusiasts.

Astell&Kern not only brings us portable audio players alone, no, they have also been collaborating with other big industry players such as Crystal Cables, Beyerdynamic and Jerry Harvey Audio. They have released a number of cables, headphones and In Ear Monitors with these three brands, and continue to do so.

Together with Beyerdynamic, Astell&Kern has brought out headphones like the AK T5p, AK T1p or In Ear Monitors like the AK T8iE and now its successor – the AK T9iE.

About AK T9iE:

The AK T9iE is a single dynamic driver universal earphone. There is no mention of the driver-size on Astell&Kern’s website, but my guess is it should be around eight to ten millimetres. I couldn’t find any values for sensitivity, but it has a rated impedance of 16 Ohms and a frequency response of 8Hz – 48kHz. During my tests I found the T9iE to be relatively normal to drive. It doesn’t need any excessive power to reach high volumes, nor does it get loud at low settings.

Astell&Kern AK T9iE

Astell&Kern AK T9iE

The housing of the AK T9iE is made of ceramic, just like the T8iE. The T9iE uses a newly developed acoustic chamber design. Beyerdynamic gave the T9iE a bigger vent for pressure exhaustion, which is said to have resulted in a very deep and well controlled low end. The T9iE has a dual layer grill-filter system at the nozzle. This not only protects the driver from ear-wax, but also serves the purpose of an acoustic filter.

The AK T9iE uses Beyerdynamic’s patented high-effieiency Tesla Technology and comes with a new eight-wire cable. This cable is made of Silver Plated single crystal copper and single crystal copper wires.

You can purchase the AK T9iE directly through Astell&Kern’s webshop, or from any of their authorized retailers world-wide. It currently sells for 1,299 USD.


The AK T9iE arrives in a moderately small black cardboard box. Open it and you’ll be greeted by the earphones, to which the 8-wire cable is attached. Under the first layer you will find the accessory set. You get a total of seven different sized silicone ear-tips, a leather carrying box and another three sets of Comply foam tips.

The silicone tips of the AK T9iE are very unusual, as they are not your typical bullet shape. No, Beyerdynamic formed them to be more ergonomic. They often remind me of Darth Vader’s helmet to be honest. For me, they do the trick very well, as the give a full seal.

The supplied cable is terminated to a 2.5mm balanced plug, but comes with an additional 2.5 to 3.5 pigtail adapter. There is also a short instructions book and a warranty card in the package. All in all that’s a very nice accessory set and packaging, but it doesn’t spark ultimate high end to me.

Build Quality and Comfort:

Let’s start with comfort, because this is hands-down the most comfortable universal IEM I have ever worn, together with the AK T8iE. It sits so very well in my ears and with the ergonomic tips it’s just like there’s nothing there at all.

From a build quality perspective these are very nice. They consist of three separate parts. The bottom shell, the top shell and the face plate. Top and bottom shell are in the same gunmetal colour, but the face plate is slightly lighter. The entire body is pretty shiny and if you are worried about getting your smudgy fingerprints on there, you should be. Because the AK T9iE shows you every little bit of dirt and leaving prints on it is very easy. If you’re like me and you hate that, you’ll clean them every day.

The T9iE comes with an MMCX connection, so you can cable roll if you have a suitable cable on hand. The original AK T8iE had massive problems with its MMCX sockets. Back in 2016 I owned a pair of them as well. After two months they died on me because of a failing socket. Of course the warranty covered that, but still a bummer. With the T9iE it seems A&K/Beyerdynamic is now using a more robust socket. I haven’t had any issues in the months that I used them.

Astell&Kern AK T9iE

Astell&Kern AK T9iE

Personally, I find the design of the AK T9iE very nice. Beauty is in the eye of the beholder of course and you’re free to disagree. No harm. The right side has Astell&Kern’s logo printed on it, while the new Beyerdynamic logo (not a fan) is on the left.

The isolation of the T9iE is okay. Since it’s a back-vented design there is some sound leaking in and out. So don’t expect them to take down the 26dB of a CIEM. The insertation depth isn’t very deep, as the T9iE sits closely at the beginning of your canals.

More about the AK T9iE on the next page.

4.5/5 - (193 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 December 18, 2019


    The housing of T8iE was definitely NOT ceramic, but actually a plastic coated with metal.

    • Reply December 18, 2019


      Hi Daniel,
      thanks for your comment.
      That’s interesting, I always was under the impression that the T8iE was made of ceramic… Sorry for that, my mistake then! Thank you for pointing it out. Always good to gather new information. 🙂

      • Reply December 18, 2019


        Hi Linus, the AK T9iE isn’t ceramic either, and uses the same PVD finish as Xelento/T8iE as per their website. Would be lovely if it were ceramic.

        • Reply December 19, 2019


          Hi Daniel,
          thanks again. Very helpful!
          Have a great week and enjoyable holidays. 🙂

  • Reply January 17, 2020


    How T9ie sound pair with SE100?.

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