Written by Cheryl Tan


We’re back with some high-end audio gear this time around! Today we’ve got the Astell & Kern T9ie in-ear monitors (IEM), co-designed with Beyerdynamic. It’s the successor to the previous T8ie, and the third in-ear collaboration between the two brands. 

While we’re not paid to do this review by anyone, I do have to give a big shout out to AV one for loaning us the t9ie as well as the Astell & Kern SP2000 audio players to do this video. 

Astell & Kern are more well known for their digital audio players than their in-ear monitors, but if you’re looking for gear that’s been tuned specially to work in harmony with each other, this might be what you’re looking for.

The T9ie is specially designed to complement Astell & Kern’s audio players, and while it works well with laptops and phones, it really shines when paired with a high-resolution source that has enough power to bring out the best in these earphones. 

Let’s talk about design. The shells are small and lightweight enough, with the same angular lines and design sense that you’ll find in Astell & Kern’s offerings. The faceplate is a matte, dark grey that’s cool to the touch and is PVD coated. It definitely looks good and feels premium. 

The cable that comes provided is a 4-core 4N pure silver and 7N OCC copper hybrid cable with MMCX connectors, terminating in a 2.5mm 4 pole jack. I have to say I really do like the aesthetics of this cable as opposed to the standard black sleeved cables. Depending on which camp of thought you believe in, you might either believe in cables making a difference in the sound or not. I personally am a believer, not so much in cable burn-in, but that the material of the cables does alter the sound. 

There’s also a memory wire sheath that holds its shape quite well and isn’t as annoying as other cables out there. I wear glasses and I’ve always disliked the memory wires on other cables because I have to fiddle with the cable when putting the earphones in. These don’t pose as big an issue though. 

There’s also a 2.5mm to 3.5mm adapter included in the package which is useful if you’re using these earphones with your laptop or phone. But as mentioned before, these are designed for use with Astell & Kern audio players, which offer a balanced 2.5mm output. 

Sound-wise, these sound like how you would expect something from Beyerdynamic to sound. The T9ie has been tuned differently from the T8ie, with slightly less bass, resulting in an even more reference sound. These earphones are using Beyerdynamic’s Tesla technology, allowing for a lower impedance so that you can use these with your phones if you don’t have a dedicated audio player.

The bass is clear, and you definitely get impact and punch in the upper registers, but I do feel that the sub-bass and decay is a bit lacking. This can be adjusted via EQ however, so it’s definitely worth a look if you like the reference tuning but want to increase the sub-bass just a touch.

Mids are pretty refined here, with excellent transparency. Listening to Billie Eilish’s Bad Guy, you’ll be able to hear the vocal layering clearly. I do like the flatter response here, with a more neutral sound, which works very well for when I’m trying to really get immersed in the intricacies of a track.

Female vocals and highs soar with this IEM, with enough airiness and crispness while not ever touching the line of sibilance. Vocals do sound natural but definitely a little cooler than I prefer.

The soundstage is spacious, not quite as expansive as some other IEMs, but imaging is absolutely spot on, and the separation and layering of instruments and vocals is fantastic.

There are a few drawbacks, however. First is driver flex. This happens when dynamic drivers in an IEM bend due to the pressure that forms when the user inserts the earphones into their ears. The air inside has nowhere to go or is unable to escape through vents quick enough, so the diaphragm of the driver bends, resulting in a crinkling sound when pressing the earphones in after a seal has already been created. 

The T9ie has a new acoustic port vent on the faceplate that’s designed to increase bass response, and I’ve never been one to attribute earphones failing to driver flex, so I don’t think the slight flex will pose much of an issue to the T9ie. 

The second is, of course, price. Ringing in at S$1,999, this is one expensive investment. Granted, if you have the dough to obtain an SP2000, this isn’t going to be much of a question. But for people who are looking for their next high-end IEM upgrade and still want to stick to a reasonable budget, it might be a bit of a stretch. I honestly think that if Astell & Kern had dropped the price a couple of hundred dollars, it might be a bit easier to swallow. At S$1,500 or S$1,600, I would definitely find it easier to recommend this to a wider audience.

Right now, I can safely say that if you already have an Astell & Kern audio player, this is a good IEM to get. Otherwise, there are definitely other IEMs out there that offer a similar sound at a lower price point. But of course, you won’t get to say they’re Astell & Kern and Beyerdynamic branded.