Knowles, industry leader in BA design and production, teaches us about IEM design & tuning

Andrew Bellavia (Twitter) of Knowles Corporation gave a talk at AES@NAMM 2018 last month on the 27th of January and went into depth about the acoustic science behind in-ear monitors and multiple balanced armature acoustic design.
Continue reading Knowles, industry leader in BA design and production, teaches us about IEM design & tuning

Quick Thoughts: Audio-Technica ATH-LS200

Editor’s Note: This overview of the Audio-Technica ATH-LS200 is based off multiple listening sessions at headphone stores and shows, without sustained personal time with the product. Thus, it should not be regarded as a full review — in fact, our entire ‘Thoughts‘ category of articles is not meant to house comprehensive reviews. Continue reading Quick Thoughts: Audio-Technica ATH-LS200

Quick Thoughts: FIIL Carat

You’ve probably have read the review of the Diva Pro by Mr. T here on CYMBACAVUM. At their price point, the Diva Pros were impressive, so we were excited to hear about FIIL‘s Bluetooth in-ear line up. We contacted FIIL regarding their Carat and Carat Pro, and received a pair of Carat for review. (At the time, the fitness-tracking Carat Pro was still being refined.)

I am also currently working on a comprehensive review of Bluetooth IEMs and headphones, with comparisons between all of them, including the FIIL Carat, so keep your eyes open for that article!

The Carat is a sport-oriented bluetooth IEM from FIIL with a fashionable design. They utilise what I call “wired between the ears” approach, used by IEMs like the Plantronics BackBeat GO series. Specifications of the Carat are not published on the English version of their website, but basic features, such as battery life and shape, are the same as the Pro version. However, the Carat lacks few features of the Carat Pro, such as a heart rate monitor or built-in music storage.

The FIIL Carat has a glossy black body.

In terms of packaging, the Carat comes in sleek and modern packaging. (My package got searched by HK’s customs, and was damaged in the process — ouch — so it was not photographed.) The Carat come with various sizes of silicon tips and ear wings, which are extremely helpful in keeping the IEMs inside your ears despite the the IEMs themselves being on the weighty side. Also included are choker clips with which to shorten your cables, ear guides that go behind your ears, a micro-USB cable, and a nice pouch. Overall packaging and accessories are well appointed.

The IEM themselves are on the heavier side, as the batteries and circuitry are built into the main IEM housings. The housings are glossy and are very smooth to touch. While on the larger side, the Carat fits in my smallish ears comfortably, unlike some other larger bluetooth IEMs which had failed to do so. The strain reliefs on the IEMs are, for some reason, red on the both sides. My guess is that it’s for the aesthetics. Nevertheless, it’s very easy to tell which side is which, so it shouldn’t be an issue. The hexagon shape is unconventional, and rather pretty in my view. As you turn the Carat on, you’ll notice the LEDs on both sides of the IEMs. The LEDs can be turned off, or set to a different color, if you prefer.

The Carat comes with a handful of features, such as a dynamic EQ, which will change in setting according to your running speed (spectacular for athletes), voice command, and a simple pedometer. The accuracy of the pedometer wasn’t tested as I simply don’t use the feature. The pedometer cannot be turned off, but I was assured that it consumed very little battery. One of the key features of these IEMs are the ear guides and the ear wings, which allows the IEMs to stay in your ears even in the most extreme environments. They stay in my ears just as well as my CIEMs do, and will certainly not fall off your ears even when exercising. A hard pull on the cable might successfully dislodge the IEMs from your ears, but that is an unlikely scenario as the cables go behind your neck.

Unlike the Pro version which is designed around a balanced armature driver, the regular Carat comes equipped with dynamic drivers, so I wasn’t expecting too much in terms of sound, and I was mostly right. The Carat displays a typical V-shaped signature with boosted bass and treble. The mids are recessed, although still enjoyable. Extension is good in both upper and lower end of the spectrum. The Carat sound like it was made for a workout, and that’s exactly what it is meant to do. The bass rumbles powerfully (perhaps to the point that it’s a little boomy), and the treble is aggressive and sparkly (although not to the point that it’s painful). Details are fairly ample, and soundstage is wide enough for outdoor use. It’s certainly not meant to compete with audiophile grade IEMs, but they’re not that bad either. I find the Carat to fit my exercise mood very well. While the Carat don’t sound exceptional per se, I find it to stays true to its intentions. After all, it sounded decent enough for me to have used it as my daily driver for two weeks.

Despite being equipped with dynamic drivers, the vents on the Carat face inside your ears, and hence the Carat doesn’t leak much sound and isolates fairly well.

However, while I found the Carat satisfying in most regards, I found the battery life to be a bit short of what I had hoped for. With the LEDs on, the battery on the Carat only lasts around four hours or so. With light use, the Carat should last the whole day, but heavy users will find themselves charging the Carat every few hours. To help with the battery life, Carat turns off automatically when worn like a necklace around the neck (the built-in magnets allow the housing to snatch onto one another). This helps improve the standby battery life, but not the actual use time. While the Carat will last a full workout session easily, it won’t survive a full day of use.


With its water resistance and active sound, the Carat was designed for a serious workout. It packs a slew of features into a small attractive housing. For the month I’ve used the Carat, I was quite satisfied with them, although I wish that the battery lasted a little longer.

On the other hand, the Pro version of the Carat has been successfully funded on Kickstarter, and I am very excited to hear what FIIL could do with BA drivers!

Critical Analysis: 1964|ADEL — Science or Science Fiction?

Editor’s Note: At CYMBACAVUM, we’re constantly trying to bridge science with the wonderful audio experiences we have. @miceblue takes on an scientist’s curiosity to examine Asius Technologies and 1964Ears’ ADEL — how it functions, the scientific principles behind it, and what it might or might not be. Continue reading Critical Analysis: 1964|ADEL — Science or Science Fiction?

Quick Thoughts: Ion by Soranik

Editor’s Note: Our thoughts are based on pre-production, prototype units of the Soranik Ion and may not necessarily be fully indicative of the state of the final production models. Pictures were generously provided by Soranik.

In the grand scheme of things, the financial requirements for becoming a custom IEM manufacturer are not all that stringent. You need some acrylic (or silicone), curing apparatuses, some cutting and polishing tools, a low-power field microscope, basic knowledge of circuit design, and some elbow grease — it’s no wonder several home-brew companies have popped up the past few years.

While these companies don’t necessarily have the marketing clout of, say, a Westone or Shure, they often have the charm of a singular purpose and philosophy, along with an assiduous moxie. If there is one major thing we here at CYMBACAVUM really care about when it comes to companies putting out new products, it’s effort. A product needn’t be “groundbreaking” or paradigm-shifting; what matters is that the company develop their products in a systematic,  thoughtful manner, applying scientific principle and craftsman art to a new offering.

Soranik is such a company. It’s small, it’s new, and it’s looking to gain some recognition, with one unique feature — it’s from Vietnam. Few Vietnamese companies populate the world of head-fi; Sunrise Audio comes to mind as the one major OEM/ODM with aspirations to maintain its own brand, but none have arisen from the bottom-up until now. Thus, it’s no wonder that young, cosmopolitan guys are at the helm of Soranik — Hieu Tran, the head designer, grew up in Vietnam but studied in the United Kingdom at the University of Warwick for an advanced degree in statistics and applied mathematics. It was during this time that he developed his interest in IEMs and tinkering with circuits.

However, the sonic inspiration for Soranik is not English, but Japanese. A lifelong fan of anime and admirer of the kaizen spirit of the Japanese, Tran (and his partners) developed a penchant for Keita Suyama’s FitEar IEMs and wished to localize a similar kind of sound in Vietnam. They began a few years ago, in a quasi-stealth mode, creating custom in-ears on a by-request basis. But Tran noticed that most people preferred the convenience of a universal, and being an owner of a TO GO! 334 himself, embarked on designing what he considered to be an augmented version. The result is the Ion, the first model Soranik is offering to customers beyond the familiar circles of the Vietnamese audio and musician community.

The Soranik Ion is inspired by FitEar but is a completely new earphone from the ground up.
The Soranik Ion is inspired by FitEar but is a completely new earphone from the ground up.

On first glance at the Ion, the FitEar inspiration is striking. It uses large, keyed two-pin connectors in the same way and the default colorway is near-opaque black, just like the TO GO! series from FitEar. The nozzle exit is clear, and the milled titanium tubes can be clearly seen. The build quality is good — not quite as precise as that of FitEar’s, but decent all-around. Tran spent years doing remolds for his friends before being confident enough to begin designing his own universal mold. Don’t mistake the Ion for a bizarro-esque imitation of the TO GO! 334, however —- the guts of the Ion are completely different and engineered from the ground-up to be its own beast. Soranik is rightly proud of the sweat and tears poured into the conception of the Ion, as it is the culmination of about two full years of research and experimentation from Tran.

The array of accessories for the Ion is standard-fare for a premium, custom-derived IEM: waterproof Pelican case, removable cables, and a wipe cloth.
The array of accessories for the Ion is standard-fare for a premium, custom-derived IEM: waterproof Pelican case, removable cables, and a wipe cloth.

Undoubtedly, many people will end up listening to the Ion in the months to come. They’ll share impressions on the positioning of the vocals, the slam of the bass, yada yada yada. What they won’t often mention, is how laborious the R&D process was for Tran. He tried just about everything, going through multiple different prototypes and developing his own titanium tube milling process. Ready-made titanium tubes, he felt, were too thick and made the music sound coarse. Apparently, the thickness and smoothness of the tubing affect more than the size constraints of an IEM; sonic resonances are measurably and subjectively affected as well. Local CNC contractors didn’t have the skill or patience to process low-volume, high technical requirement orders like his. So he learned to mill titanium on his own.

His main goal, though, was to improve the molasses-like bass of the 334 while preserving its vocal richness. And like a good engineer, he attempted to rectify these shortcomings with precise control of acoustic low-pass filters and judicious, minimal use of passive components.

The FitEar-style two-pin connector sockets are hand-molded.
The FitEar-style two-pin connector sockets are hand-molded.

He first sent CYMBACAVUM a prototype in September last year — a dual-woofered, dual titanium tube behemoth. They were really tip dependent (though Taylor Swift always sounded awesome with them), ranging from caramel vocals in a deep fit to energetic highs in a shallow one, and while they shared common traits with the 334, the soundstage presentation was very different. The prototype Ion had a wider, flatter soundstage, and was less smooth sounding. Fit was also a little awkward, as the nozzle exits were a bit long, causing the prototype to hang loosely off the ears. We suggested that Soranik rework the Ion prototype — mainly for purposes of ergonomics.

Fast forward six months, and the new Ion is completely different. Not only is it now much more comfortable, the sound signature is reworked. Tran collected feedback from us and others to create a different, crowd-pleaser type of signature — a good deal of bass, but well done and without strangulating impact/stuffiness. It still maintains good clarity, but with a kind of fuzzy warmth that many people like, and with the treble being smooth enough such that extremely compressed music (e.g. K-Pop) doesn’t sound horrible, all while preserving good treble extension.

The bespoke titanium tubes are a self-spun R&D project for Soranik.
The bespoke titanium tubes are a self-spun R&D project for Soranik.

Variance in sound signature due to depth of insertion is now not as variable (but is an unavoidable feature of sound physics), and coupled with the vastly improved fit, the Ion is comfortable as can be. We love the performance-style braided cables as well — these type of cables are sorely lacking in FitEar’s staple of 000/001/002/003/004/005 cables.

The Ion is a labor of love from Soranik, built with the kind of effort we here at CYMBACAVUM can really appreciate; we can’t wait to see what others have to say about it!

For more information, please visit Soranik’s Facebook page.

Celsus Sound: Trailblazing Wireless Freedom

Editor’s Note: Another incredibly late article — apologies to everyone all around! We’re extremely limited on time!

Last year, I had the good fortune of meeting with Jason Lim, co-founder and former CEO of Nuforce. Since leaving Nuforce (the company is now a subsidiary of Optoma), Mr. Lim has been busy. He founded Heap Venture, a holding company with a multi-pronged approach to home and personal audio. Aside from NuPrime, a direct vestige of Nuforce’s home audio products, Lim embarked on a completely new audio category with Celsus Sound. The bold, ambitious stated mission and purpose of Celsus Sound is the production of superior portable audio products for discerning music lovers, setting quality above all else. As the pilot brand of Heap Venture, Celsus Sound is focused on the premium market and it has attempted to do so with the Companion One. For example, solely in terms of build, the Companion One is milled from a single ingot of aluminum, with top and bottom covers cut from Corning Gorilla Glass.

The Companion One is the first of a new wave of wireless portable DAC devices.
The Companion One is the first of a new wave of wireless portable DAC devices.

The main trick up the sleeve of Celsus Sound, however, doesn’t involve the outer appearance of its products, but rather the inner guts. When it came out in the middle of last year, the Companion One was the world’s first portable DAC device to wirelessly stream high-resolution audio (up to 24-bit, 192 kHz) over wireless networks. While other devices have since attempted to bridge the gap, the Companion One came first, and it’s what we’ll quickly highlight here.


In order to do high-resolution, 24/192 PCM streaming over a typical 802.11 network, the Companion One had to utilize newly developed hardware from SaviAudio. The Taiwanese design startup (and hi-fi focused subsidiary of the larger, fabless ASIC firm Savitech), whose previous offerings were mostly for the budget-minded, developed a wireless streaming module dedicated to high-end audio. A naked demonstration of its capabilities are shown below:

Thus, this wireless streaming module, together with a 32/384 and DSD-cable USB receiver (SaviAudio is mostly known for its USB receiver modules) form the streaming digital heart of the Companion One. In turn, digital-to-analog conversion duties are handled by the now-ubiquitous ES9018K2M two-channel chip from ESSTech, kept pace by dual low-jitter oscillators (one for 44.1 kHz multiples and the other for 48 kHz multiples). The result is a very respectable >115 dB(A) SNR under a 10 kΩ load.

As for the analog end, the Companion One employs the OPA1612 for I/V conversion and the AD8397, doubling in duties for both voltage gain and current buffering. Celsus claims that the unit’s signal path and headphone amplifier circuit have been “painstakingly optimized for maximal headphone performance. ” The result is actually pretty impressive, pumping out detailed but liquid audio.

The Companion One, paired with Celsus Sound's Gramo One earbuds.
The Companion One, paired with Celsus Sound‘s Gramo One earbuds.

The Good: Mobile Device Connectivity

Setting up audio streaming via USB is as easy as plug and play, whether it be from my main mobile companion the Apple iPhone 6, or from any Android device. The sound quality, as mentioned, is great. I did experience a snafu during the latter stages of my loaner experience where an accidental press of a weird combination of keys tripped off the USB functionality, but the majority of the time, pairing mobile devices with the Companion One has been a breeze, and Celsus Sound provides Lightning, 40-Pin, micro-USB, and regular USB cables for connecting your devices — keyed for easy recognition, and no CCK or extra dongles necessary.

The Bad: How Minimal is too Minimal?

I can appreciate a nice minimal design aesthetic. The Companion One might resemble an oversized smartphone and these days smartphones don’t have many buttons to them, but this thing is still a DAC and the Companion One is just a toggle or two shy of a good user experience. Why use a button for selecting between wi-fi and USB, or between infrastructure and access point mode, when a toggle is far more intuitive?

Celsus Sound Companion One

The Ugly: Wireless Streaming

Alright, let me hit you with the bad news. The really bad news. The wireless streaming function has problems.

And when I write, “problems,” I mean the kind that will occasionally stutter your audio, color it with clicks, and lag hard enough to make a gamer break down in tears. Whether it is thru access point mode or client mode, via iOS AirPlay or Android DLNA, the latency from input action to device reaction is about 2-3 seconds. So that means that watching a YouTube video on your smartphone will not have synchronized audio, and skipping tracks as well as changing volume on iTunes is a waiting game.

Furthermore, streaming over Windows is not straightforward, unless you’re running iTunes’ AirPlay function, rather than DLNA via Windows Media Player. However, even AirPlay via Windows has issues, as volume will reset every single time you restart the program — the Companion One doesn’t seem to store volume data in memory for some reason (even though it does so through wired USB playback). If you’re using a sensitive earphone, don’t have them in your ears when you press play, lest you expect to be blasted with ear ringing SPLs.

So yes, to say that Celsus Sound has some kinks to work out with the streaming aspect of the Companion One‘s functionality is to be kind. At the same time, Celsus is not the only company with lag problems; even the insanely expensive Astell&Kern AK320 and AK380 have had issues with lag upon playback with its AK Connect app, though the problem isn’t as severe.

For all its issues, the Companion One does get the distinction of being the first device to pull off this wireless streaming capability — perhaps it is Celsus‘ way of navigating blue oceans, but I have to applaud Jason Lim for taking a risk and releasing products that few others are considering.

Celsus Sound Companion One

I mean the kind that will occasionally stutter your audio, color it with clicks, and lag hard enough to make a gamer break down in tears.

So let’s get on with the good news. The Companion One is 100% firmware upgradable, and all of these problems are solvable via software updates. The hardware is fine. The software isn’t — yet, especially when you’re a small company attempting an ambitious endeavor to stream both via AirDrop and DLNA on both desktop and mobile devices. The bottom line is that the Companion One, as cool as it is, is not quite ready for wireless primetime.

If you must get the Celsus Sound Companion One, get it first as a traditional portable DAC/amp. It works seamlessly with iOS and Android, as well as OSX. There are driver issues with Windows. There are more serious and crippling issues with wireless streaming. But it works well as a DAC, and the wireless capability will come along soon enough.

The Biz: E-Earphone’s CIEM Store in Akihabara, Tokyo

Founded by an Osakan man with a full head of hair and a hope to spread the spirit of porta-fi to the masses, E-Earphone is one of Japan’s premier personal audio store chains, with storefronts in both Tokyo and Osaka metropolises.

Its aisles upon aisles of headphones and earphones are famed to the enthusiast community, and when the CIEM specialty store opened its doors last August, Nathan of OHM Image and Headfonia went to take a look (link). This glowing report of toys abound convinced me that it had to be a must-see stop while I was on vacation in Tokyo last month. Continue reading The Biz: E-Earphone’s CIEM Store in Akihabara, Tokyo