Superb balance and refinement, Considerable technical bump over predecessors, Spacious stage, High-quality cable and shells, Usable tuning nozzles
Spring Tips can be fiddly, Treble extension just average, Heavy shells
The KXXS-platform remains Moondrop’s most accessible product range to a wide range of consumers and the KATO is its best and most complete incarnation yet.
I’m sure most of us are familiar with Moondrop, if you’re looking for a balanced and critically well-received IEM, then their products would have undoubtedly popped up. Much of this success can be attributed to the original KXXS. Though not their runaway hit, it definitely put the company on the map as a serious brand that wouldn’t fade into obscurity after just a hit or two. Upon this single-DD foundation and using the same base shell design, the company would go on to slash the price with the Starfield and further with the 2021 Aria. The KATO represents the true successor of the KXXS, being the first model to return to its slightly more premium price point while touting performance to match. The company spent 2 years independently developing a driver for this earphone and optimising the surrounding acoustics. It introduces quite a few new features too, including tuning nozzles should you want to subtly alter the company’s popular VDSF house sound and Moondrop’s new Spring Tips.
The KATO retails for $189 USD. You can read more about it and treat yourself to a set on Apos Audio.
I would like to thank John from Apos and the team at Moondrop very much for reaching out to organise a review of the new KATO. All words are my own and there is no monetary incentive for a positive review. Despite receiving the earphones free of cost, I will attempt to be as objective as possible in my evaluation.
- Drivers: 10mm-ULT dynamic driver
- Housing: MIM stainless steel
- Frequency Response: 10 Hz – 45 kHz
- Impedance: 32 ohms
- Sensitivity: 123 dB
Behind the Design
ULT Dynamic Driver
Moondrop independently developed their own 10mm dynamic driver featuring their ultra-linear technology. This encompasses a lighter imported CCAW voice coil, high-frequency waveguide in addition to a new, more efficient magnet structure. Moreover, the magnet structure has been designed to promote linear air circulation to prevent modal breakup.
3rd Generation DLC Diaphragm
The market is now quite familiar with diamond-like carbon dynamic drivers that offer a more rigid diaphragm, translating to a more detailed sound. Moondrop is using a 3rd generation composite DLC diaphragm which implements 3 materials for different parts of the diaphragm. This has allowed the company to optimise rigidity, damping coefficient and weight. The company employed FEA software to find the ideal composition and geometry which has enabled them to reduce non-linear distortion by 80% relative to previous generation DLC diaphragm drivers.
Tuned Acoustic Chambers
Once again, the company leveraged FEA to simulate the acoustics surrounding the driver and derive the ideal geometry. The front cavity works in tandem with the high-frequency waveguide to provide extended highs and phase coherence. It appears to do so with a horn structure. Moondrop reasons this provides superior sound staging.
In addition, Moondrop is launching their new in-house developed silicone ear tips. These tips are designed to improve wearing comfort and isolation in addition to improving high-frequency linearity by reducing resonances (ie. treble peaks).
Moondrop continues to improve their packaging with each iteration of their products, and the KATO is no different. It comes in a large box with signature Moondrop waifu art on the exterior. Sliding off the sleeve reveals a bi-fold hard box containing the earphones and accessories. Buyers receive a blue leather carrying case with a magnetic latch in addition to a pocketable drawstring pouch. To the side are the earphones themselves and a plastic container housing the 6 pairs of ear tips, 3 memory foam and 3 pairs of Moondrop’s new Sping Tips – more on these later. In addition, the KATO comes with two sets of modular screw-in nozzles that allow the user to fine-tune the sound. They come with a handy metal plate to keep things organised. Finally, the cable lies below, a new design also for the KATO. A comprehensive unboxing experience with a useful set of accessories.
The KATO works well from a thematic standpoint, being clearly derived from the base KXXS shell as we’ve seen reincarnated time and again on the cheaper variants since. However, here, it has been taken to the next level. The KATO features a weighted, mirror-finish stainless steel complexion augmented by striking angular machining that gives it awesome dimension and contrast. Though the un-coated finish may be prone to scratches, they are easily polished like CFA’s steel IEMs. This will appeal to those that experienced finishing issues on Moondrop’s former metal shells. A new addition is the modular nozzles that screw in and are retained by a small o-ring. While there is no mesh covering the driver below, Moondrop does state that they’ve carefully considered the filters in the nozzles themselves to promote prolonged performance.
The new cable is a large gauge SPC unit that looks and feels far more substantial than those that came with any prior Moondrop IEM. Connecting via your typical 0.78mm 2-pin interface, aftermarket options are abundant should it not be to your tastes. The stock cable satisfies in many regards, that said. It feels sturdy but not exceedingly cumbersome and has compliant insulation with minimal memory. My only complaint is the slight tackiness of the outer jacket. Otherwise, the soft pre-moulded ear guides are comfortable, and the metal connectors offer visual congruence to the housings themselves. I was impressed by the strain relief and feel overall. My only complaint is that it would have been good to see modular connectors similar to the Variations and as some competitors at this price tier are beginning to assume.
Fit & Isolation –
With a base shape identical to the KXXS and Starfield, expect a very similar fit experience. It’s a shape that few should have issues with unless you have especially small ears. The D-shaped shells are reasonably compact by modern standards and also relatively low-profile – though the faceplates do protrude a little further than the Aria in this instance. Whilst not ideal to sleep on, they are comfortable to wear and smoothly formed, creating no hotspots for my ears over extended listening. The angular inner housing also doesn’t affect ergonomics at all, the edges are rounded so they don’t suffer from the same sharpness as early CFA IEMs for instance.
The nozzles are now slightly larger, but this isn’t really felt as the fit remains on the shallower side. This further aids wearing comfort as there is minimal pressure and zero driver flex. Wind noise also isn’t an issue when outdoors as the vents are all on the inner face. In return, passive noise isolation is just mediocre, sufficient for public transport and general commute but won’t be ideal for especially noisy environments.
Spring Tips –
I will discuss these tips here as they have a very unique design and, increasingly, we are seeing the ear tip play a larger role in IEM design. The Spring Tips have a relatively elongated dome promoting a slightly deeper fit. Furthermore, they are made from a very soft, slightly sticky silicone almost reminiscent of the TPE Xelastec tips. It isn’t quite to the same extent so they aren’t as fiddly to put in, but they’re still noticeably tackier than regular silicone tips. The stem is constructed from a harder silicone that aids retention on the nozzle. Though no mechanism is evident, the softer construction aids a flexible aperture somewhat similar to Final’s E-tips. Meanwhile, ridges reinforce the outer dome to form a better seal with the canal – I have found some softer tips like this to collapse in the ear, these don’t suffer from this issue. They also have a horn structure at the aperture to enhance high-frequency reproduction similar to the older Phonak ear tips, a very interesting design. I’ll touch on sound impressions in my sound breakdown.