Description

This is a pair of 8mm earphone drivers build with Micro–Tesla Driving Technology and Ultra Wide Band performance. The shell is plated with 24K gold to better resist electromagnetic interference.This is the flagship micro driver unit product of Earphone DIY Labs. Earphones built with this driver could easily outperform top IEMs like Sennheiser IE800. 

• The Micro-Tesla driving technology is characterized by maximum magnetic field to >1 Telsa focusing in the air gap inside the dynamic driver unit in a micro driving unit, which is 2 or 3 times higher than conventional IEM drivers.
• Ultra Wide Band means the driver performs excellently from 5Hz to 45KHz, which greatly outperforms ordinary IEM 20~20Khz range.
• The overall impression is very much close to Astell&Kern AT T8iE MkII using Tesla driving technology, and Shure SHR1840
• The key benefits to users are
  • The ultra high density of the bass. With precise volume, the bass is well controlled and deeply extend to ultra low bass band. It’s the most punchy while balanced bass we’ve ever tested among tens of hi-end drivers! 
  • Ultra low distortion in the mid. Vocal is precisely positioned and sounds just as it shall be.
  • Unbeatable resolution at treble.You may feel it is too bright in the 1st few seconds if you haven’t tried top IEMs like IE800, T8iE, but then you will get it’s only because the high resolution to make details crystal clear – your ears are a little bit overloaded. 

We recommend using this driver with IE800 ceramic earphone shell to fully explore its potential. Our IE800 DIY Kits also include this driver with better price.

Features and Specs

• The impedance – 16 ohm
• Diameter – 8mm
• Frequency response -5-46,000 Hz
• Nominal sound pressure level – 113 dB (1 mW / 1000 Hz)
• Total THD @1KhZ, <0.05%

The 1st Tesla unit was presented Beyerdynamic on 2013 that the flux density (i.e., the magnetic filed strength) finally reaching more than one Tesla. The increase of the flux density can provide immense advantages. The voice coils can be more filigreed and consequently react more quickly, while the sound generated gains precision and richness in detail. At the same time, the energy utilization increases and the listener can play music louder. In other terms, the more the coil is for the driver, the greater details it can push out. See the pic below where we tear open an earphone,  take off the diaphragm and showing you the magnetic structure inside.

Besides the powerful magnetic field, the diaphragm and coils of the driver is still key factors of the sound character and quality.  The diaphragm is made by Duofoil (used by most Hi-End headphones like HD800) and with a multiple Sandwich structure. The coil is CCAW (Copper-clad Aluminium Wire) which is ultra thin and light.

Measurement

Measurement is based on an IEC711 coupler, a customized USB sound card and Win10 PC running ARTA Software.

Frequency Response measurement

Notice the bass, mid and treble are perfectly balanced. There is a boost at 11~13Khz making the sound full of airyness. And the bass well extend to >20Hz.

Also notice the perfect L(Blue)/R(Yellow) channel matching! At most cases the L/R gap is <0.5dB!

Frequency Response

See following Frequency Response of Astell&Kern AT T8iE MkII as reference. Note our 8mm Tesla drivers have much better performance on 10KHz and beyond.  

CSD (Cumulative Spectral Decay), i.e., the waterfall diagram.

Notice the decay rate at 500hz-20Khz is very consistent, meaning less interference among bass, mid and treble.

Cumulative Spectral Decay

Impulse response – notice the response duration is extremely short <1.4ms (the shorter the better), meaning high resolution and punchy bass.

Burst Decay – notice the consistency among all the bands

Energy decay

Proceed with caution: dynamic drivers are with extremely fragile (1~5μm) diaphragm and can be easily damaged in following situations.

• Soldering: overheated (>250 degree C) soldering iron or overtime soldering (>2s) may permanently damage the driver. Please heat the driver as little as possible during soldering.
• Installation: the driver has Sintered NdFeB Magnetic inside with extremely strong attraction power. The fragile diaphragm may be damaged by having anything metallic hit it. 
• Gluing: attaching glue either to the diaphragm or the backside holes may greatly alter the sound
• Chemical: Applying any chemical solvent will void your warrant and we will not be able to help you
• Others: applying high-voltage, storing in high temperature/humid environment… all may cause unrecoverable damage.