Description

This is a pair of 10mm driver units with same Tesla driving technology and diaphragm as Astell$Kern AK T8iE MK II, an $1,300 audiophile In-Ear Monitor.  We custom this driver for DIYers want to upgrade their IEMs with 10mm or larger housing for premium sound quality. Working with most well designed half-open (i.e., with an aperture) IEM shells, DIYers can easily reproduce nearly 100% T8iE sound. See more details in the acoustic measurement section. 

Know about Astell$Kern AK T8iE MK II

(cited from positive-feedback)

The AK T8iEs provide one of the nicest in-ear monitor experiences that I’ve had to date. It could be that I respond well to their full range approach. The website tells us, “The T8iEs feature dynamic moving coils speakers, operating at 16 ohm and featuring a 10 mW power handling capacity. The new MK II model boasts improved voice coils and upgraded (removable)  3.5 mm single ended and 2.5 mm balanced high-grade silver speaker-plated cables.” I should confess that, for me, some balanced armature IEMs appear too intent on grabbing your attention with high frequency pyrotechnics. True, with the best amp, DAC, and recording, some IEMs bulging with speakers and looking like Peter Gabriel’s Slipperman costume can be truly spectacular. But other times, well, supper’s not quite ready (last prog rock reference, honest). Playing less than lovely recordings can make all those tiny speakers shouting for attention become unruly. Whatever your reaction to the AK T8iE’s design, it’s hard to imagine anyone finding the sound of the AK T8iEs to be anything less than cohesive and seamless. 

Tonally, the AK T8iEs excel in producing low frequencies that are articulated and convincing. Which is to say, bass guitar and lower register keyboard notes are consistently weighty and in proportion to the music. To me, this constitutes excellent bass. Others may opt for a more overwhelming presence, but these IEMs appear to be tuned for those who prefer a balanced approach. The midrange is a delight, and is particularly adept at conveying vocals artfully and significantly absent of grain or edginess. The highs, for me, deliver thrills without tearing up my ear ducts. 

Listening to Martin Zeller’s stunning performance on Bach Cello Suite, Vol.1, the tone of the lowest notes loading the microphone fills the sonic space of the AK T8iE’s with rich, rewarding sound. The sound of the bow as it digs into the string windings is exceptionally detailed, producing a highly realistic sonic image. Is it as immersive as what I hear with my Audeze LCD-Xs or as grand as when hearing the piece through my Nola Contender loudspeakers? No, on both counts. That being acknowledged, neither headphone nor loudspeaker can match the AK T8iE’s direct and personal conveyance of the performance. 

Used to be, the only people needing fancy in-ear monitors were wasted rock stars or serious looking dudes protecting the President. The rest of us settled for crappy little earbuds that could only produce one sound accurately: “Good riddance!” High end IEMs were reserved for world class X-Games competitors barreling off the mini-ramp. But times have changed, and though my only X-Games competition is struggling to put on a pair of X-Large jeans, I want the same state of the art in-ear monitors rocking the ears of the audiophile in crowd. 

The growing number of people of all ages who say, “Hey! I want a pair of killer IEMs, too!” has given rise to the many companies producing in-ear monitors of a quality and design unimaginable only five years ago. Up to now, the world of boutique premium in-ear monitors has been dominated by start-up companies drawing from the expertise of a handful of designers. The manufacturing heavyweights, however, are starting to take notice, and few companies cast a shadow as big as the German powerhouse, Beyerdynamic. 

Acoustic Measurements

See the frequency response measurement as below. Note the test is done in open space. Meaning you will get a little bit (1~3dB) boost on low bass after installation to the shell.

Also note the characteristic drop at 6Khz, identical as T8iE MK II, to suppress harmful sibilance.   

See the cumulative spectral decay and notice the unparalleled consistency from 200 to 18KHz. This is only available on drivers with Tesla magnet in extremely low distortion.

The impulse response is very fast <2.5ms, meaning this driver is with decent response, which is also reflected in the cumulative spectral decay.

Other acoustic measurement for reference. 

Soldering: overheated (>250 degree C) soldering iron or overtime soldering (>2s) may permanently damage the driver. Please managed down both in your DIY. 

• Installation: the driver has Sintered NdFeB Magnetic inside with extremely strong attraction power. Damage may caused by attracting anything hitting the fragile diaphragm. 
• Others: applying high-voltage, storing in high temperature/humidity environment… all may cause unrecoverable damage.