Review: Astrotec AM850 MK2 – A Brand New Approach

The AM850 MK2 are the latest mid-fi tier IEMs from Astrotec.
The AM850 MK2 are the latest mid-fi tier IEMs from Astrotec.

Astrotec has strengthened its current mid-fi lineup with the release of the AM850 MK2, featuring new technologies like interchangeable filter nozzles and a 2nd generation liquid crystal polymer (LCP) diaphragm dynamic driver.

Thank you to Ryan from Astrotec for providing the AM850 MK2 for review purposes.

In 2017, Astrotec released the AM850, which filled the mid-fi tier of Astrotec’s lineup. To address audio-related technological improvements and new challenges emerging over the last few years, Astrotec took a step back to revisit and refresh the AM850. Now, 5 years after the launch of the AM850, the AM850 MK2 is about to be released.

The AM850 MK2 are the latest mid-fi tier IEMs from Astrotec.
Bottom Line

The AM850 MK2 have high-quality and robust shells with creative interchangeable nozzles. The changes from the previous AM850 are drastic, and there are so many reasons for those who own the predecessors to upgrade. However, they are far from perfect. A messy treble presentation, a sticky cable, and a too-small carrying case affect the overall quality of this model.

What We Like
  • Interchangeable nozzles to tailor the sound
  • Warm midrange for casual listening
  • High-quality shell
  • Sub-bass rumble
What We Don't Like
  • A sticky cable shielding layer
  • Carrying case too small to fit IEMs with mesh bag and nozzle plate
  • Congested soundstage using the Tide nozzles
  • Unnatural and messy treble

The revised version has various upgrades, such as a detachable cable and interchangeable filter nozzles that make the AM850 MK2 competitive in the current audiophile market. In this article, we will look into the AM850 MK2 and analyze them in-depth!

Company Introduction

Founded in 2002 by several members with long experience in the audio industry, Astrotec believes in the concept of “continuous exploration”. The brand name “Astrotec” is made up of Astro (Astronomy) and Tec (Technology), which carries the meaning of embodied technical exploration and pursuit. Astrotec utilizes cutting-edge technologies in producing their products, to deliver better listening experiences to consumers.

Technical Specifications

  • Form: IEMs
  • Drivers: 1 x 2nd generation LCP diaphragm 10mm dynamic driver
  • Impedance (Ohm): 32Ω
  • Sensitivity (dB): 105dB/1mw (S.P.L at 1KHz)
  • Frequency Response (Hz): 5Hz – 35kHz
  • Cable: Four-wire braided oxygen-free copper (OFC) stock cable
  • Cable Length: 1.2m
  • Removable Cable: Y
  • Cup/Shell Jack: MMCX
  • Source Jack: 3.5mm TRS unbalanced
The black cardboard box of AM850 MK2 highlights the silver color shell printed on the box.
The black cardboard box of AM850 MK2 highlights the silver color shell printed on the box.

Packaging

The AM850 MK2 come in a black cardboard box, with their photo printed on the front. At the back of the box, technical specifications are listed clearly.

Technical specifications are listed clearly for users' reference on the back of the AM850 MK2 box.
Technical specifications are listed clearly for users’ reference on the back of the AM850 MK2 box.

In the box

  • The AM850 MK2 IEMs
  • Four-wire braided oxygen-free copper (OFC) stock cable
  • Hard carrying case
  • 6 pairs of silicone ear tips (2 different types with three sizes)
  • 2 pairs of foam ear tips
  • Interchangeable nozzle plate (for secure storage)
  • IEM cleaning kit
  • Mesh IEM storage bag
The IEM mesh bag provided in the box provide good protection to the shells against scratches.
The IEM mesh bag provided in the box provide good protection to the shells against scratches.

I typically find mesh storage bags useful, especially when storing additional accessories with the IEMs in the same case. The mesh bag reduces the chance of the IEM shells getting scratched.

However, the included case is too small to store the IEMs inside the mesh bag and the nozzle plate. The case should be large enough to fit everything because it is essential to bring the nozzle plate with the IEMs to prevent losing the small parts.

The case does not fit the mesh bag.
The case does not fit the mesh bag.

Cable

The AM850 MK2 include a four-wire braided oxygen-free copper (OFC) cable. While the cable is soft and supple, the outer shielding layer is kind of sticky. This reduces the overall quality and makes the cable feel sub-par.

Individual parts of the cable are of high quality, but the sticky feeling on the cable shielding layer makes it sub-par.
Individual parts of the cable are of high quality, but the sticky feeling on the cable shielding layer makes it sub-par.

Design

The AM850 MK2 are made from a robust and durable aerospace-grade aluminum alloy. The aluminum is machined with the aid of a 5-axis computer numerical controlled (CNC) process. Edges of the shell are highly smooth and free from any sharpness. The interchangeable nozzle has a lip to securely retain the ear tip.

There are two vents on the engraved AM850 MK2 logo on the faceplate. The two vents help mitigate dynamic driver flex.

Driver flex is when the driver bends due to air pressure against it. Usually, it occurs when you’re inserting the IEM into your ear, and air in the shell creates pressure to bend the driver.

The AM850 MK2 utilizes MMCX connectors, which are located on top of the shell. Based on my several rounds of plug and unplug, I find the MMCX port to be durable.

Overall, the AM850 MK2 are definitely a pair of well-built IEMs.
Overall, the AM850 MK2 are definitely a pair of well-built IEMs.

Internals

The AM850 MK2 use a 10mm dynamic driver with a liquid crystal polymer (LCP) diaphragm, similar to the one in the Vesna. LCP diaphragms typically have good flexibility to handle different kinds of music notes, delivering speedy attacks and clean decays.

Just like with all diaphragms, in order to produce sound, the LCP diaphragm vibrates, causing air to move, which results in sound waves. The properties and material of the diaphragm are essential to producing high-quality audio reproduction.

Interchangeable filter nozzles

One of the selling points of the AM850 MK2 is the interchangeable filter nozzles. The AM850 MK2 come with three pairs of nozzles promising different sound signatures:

  • Air (Gold): Reduced bass and enhanced treble
  • Neutral (Black): Original sound signature of AM850 MK2
  • Tide (Grey): Enhanced bass and enhanced treble

To change the nozzle, simply turn the currently installed nozzle on the AM850 MK2 anticlockwise to remove it. Install and tighten the desired nozzle by turning it clockwise on the IEMs.

The nozzles are extremely small, and I advise users to always screw them on the nozzle plate provided in the box to prevent misplacement.
Three types of interchangeable nozzles are provided in the box and each of them will result in a different sound signature.
Three types of interchangeable nozzles are provided in the box and each of them will result in a different sound signature.

AM850 MK2 Sound

Rated at 32Ω for impedance and 105dB/1mw for sensitivity, the AM850 MK2 are a pair of power-efficient IEMs that can be easily paired with various sources. As mentioned in the section above, the AM850 MK2 sound signature depends on the nozzle used, although in general, there is more emphasis on the bass and treble, as compared to the midrange.

The sound signature can be generally classified as U-shaped.

In terms of soundstage, the AM850 MK2 have a three-dimensional staging with sufficient horizontal and vertical extension. However, when the Tide (grey) nozzle is installed, the soundstage becomes narrower and there is observable congestion. Otherwise, the other two nozzles give the AM850 MK2 an expansive and uncongested soundstage.

I find that the sonic performance is the best when they are paired with powerful sources, such as the Venture Electronics Megatron.
Strong sources, like the Venture Electronics Megatron unleashes the potential in AM850 MK2, especially in bass reproduction.
Strong sources, like the Venture Electronics Megatron unleashes the potential in AM850 MK2, especially in bass reproduction.

Bass

With the Neutral (black) nozzle, the AM850 MK2 bass is tight and impactful. The sub-bass extension creates a three-dimensional soundstage. The mid-bass is more polite, as compared to the sub-bass. This tuning prevents the mid-bass from coloring the midrange.

Moving to the Tide nozzle, the mid-bass turns more meaty and bold. The overall sound signature becomes warmer, with significant coloration to the midrange. The boosted mid-bass bleeds towards the midrange, causing degradation in clarity. Besides that, as mentioned previously, due to the thickening of bass notes, the spacing between each note is reduced and causes congestion.

The presentation on the Air (gold) nozzle is the most balanced. The bass quantity is reduced, while accuracy is improved. The bass notes are leaner and their attacks and decays are more speedy, resulting in a more precise bass response.

I find the air nozzle to suit me the most in terms of bass as I prefer accuracy, rather than huge or uncontrolled bass.

The titanium color scheme of the AM850 MK2 matches well with my MacBook.
The titanium color scheme of the AM850 MK2 matches well with my MacBook.

Midrange

The AM850 MK2 have a recessed and warm midrange. The midrange has significant coloration from the mid-bass, especially when the Tide nozzles are installed. The enhanced mid-bass does bleed towards the midrange and increases its warmth. As a user who emphasizes cleanliness and transparency in the midrange, I find the midrange muddy when the Tide nozzles are used.

Changing to the Neutral nozzles, the midrange coloration from the mid-bass reduces significantly. The midrange is still warm, but not to the extent of being muddy. I will classify this quality of midrange to be suitable for casual listening. After a long day of working, it is comfortable to have a smooth and warm midrange to end the day. I am glad that the AM850 MK2 can deliver this to me.

On Air nozzles, the midrange becomes more airy and transparent. It is now closer to critical listening standards, with good quality of detail retrieval capability and minimum coloration.

Out of the three nozzles, I use the Air nozzles more than others because of their transparency.

The midrange of AM850 MK2 is warm and smooth when paired with the Neutral nozzle.
The midrange of AM850 MK2 is warm and smooth when paired with the Neutral nozzle.

Treble

Here’s the deal-breaker – I find the treble stiff and hot.

The AM850 MK2 have a high amount of detail and information in the treble and they push the treble forward to the extent that notes are crumpled together, forming a stiff and unnatural presentation. I find all three nozzles to be the same in this regard.

There is an insufficient amount of air and space for each treble note to separate itself from other notes. All of them are stuck together and bombarding the eardrums at the same time. The presentation is messy, and I cannot get useful details from the treble no matter how hard I try.

It is a waste that such eye-catching IEMs have a serious flaw in sonic performance.
It is a waste that such eye-catching IEMs have a serious flaw in sonic performance.

Where to Buy

Conclusion

The AM850 MK2 have high-quality and robust shells with creative interchangeable nozzles. The changes from the previous AM850 are drastic, and there are so many reasons for those who own the predecessors to upgrade. However, they are far from perfect. A messy treble presentation, a sticky cable, and a too-small carrying case affect the overall quality of this model.

Priced between USD$150-$200, I expect at least a pair of clean and proper-sounding IEMs. The flaw in the treble is definitely a deal-breaker, at least for me. I hope that this imperfection provides a good learning opportunity for Astrotec to take note of when designing their future releases.

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