THX Onyx – Design and Features
The Onyx isn’t your average headphone adapter. For starters, it’s much bigger at just over 8-inches long. That added length allows it to be far more robust than your standard dongle. Both ends are enclosed in metal housings and the length of cable in between is long and flexible enough to make sure either end isn’t torqued when taken in or out of a pocket. There’s also built-in strain relief to protect it further. The cable is sleeved in a soft-touch rubber, which is nice to handle and should outlast a normal braided cable. Each housing also built in magnets for some quick cable management, though this didn’t work well with my Note 20 using a case.
A good portion of that length is to accommodate the high-end headphone amp and DAC arrangement inside the bigger housing. The Onyx uses THX’s AAA-78 amplifier and an ESS ES9281PRO DAC (digital-to-analog converter) to deliver its audio wizardry, generating enough power to drive even high impedance headphones, all without over-taxing your device’s battery. Make no mistake, the Onyx may look small compared to larger DACs, but it puts out more power than something this size has any right to.
The big question gamers and average listeners often ask when presented with a product like this is “why.” When most of us are content with what we have when it comes to audio, what makes a device like the Onyx worth investing the cost of three games into? The answer comes in how the device renders sound and the amount of electricity it’s able to push to your headset.
When connected, the Onyx completely replaces the tech built into your smartphone or gaming PC (it’s plug-and-play with both using the included USB Type-C adapter). To put it in simple terms, phones and computers are noisy places, filled with electronic distortion from all of the other work the device is doing to, say, run a graphics card or pick up wireless signals. The Onyx pulls audio processing out of that chain and physically separates it as a first step, but it doesn’t end there. The next step is upgrading the sound processing hardware with the premium components and high-resolution rendering. These things together make it a near-guaranteed upgrade for any phone or even high-end gaming desktop.
The highlight feature of the THX Onyx is absolutely the AAA amplifier, and is a big piece of the answer to “why.” THX AAA has become quite popular among audio enthusiasts due to its exceptionally clean and quiet sound, removing any white noise or distortion from what you’re listening to. It’s the same technology used in some of the company’s best desktop amps, such as those sold by Drop.
AAA amplifiers stand apart from the pack due to their proprietary “feed-forward” error correction technology, which is how they’re able to deliver that distortion-free sound. According to THX, the distortion the amp is removing isn’t limited to static or other sounds that would necessarily stand out in normal listening either. Instead, much of what’s being removed is quiet noise that reduces the detail in what you’re listening to and eventually leads to fatigue.
In fact, this is distortion you may not even perceive until you listen to a device without it, similar to going back to SD from an HD screen. The AAA-78 amp is also exceptionally quiet, so even when nothing is playing, you won’t hear any white noise even with sensitive earbuds.
In combination with the ESS ES9281PRO DAC, the Onyx is able to offer chart-topping on-paper specs, capable of sending audio at 32-bit/384kHz resolution. (For context, Tidal Master Quality tracks are typically only 24-bit/96kHz and are considered some of the highest quality streaming audio available today.) Practically speaking, it’s higher than you’ll actually be able to tell a difference with. The dynamic range, or the span from quietest to loudest in distortion-free content, is also excellent at 118 dB. Many competing products, such as the AudioQuest Dragonfly Cobalt, fall short of this despite costing more. In practical terms, that means the Onyx can deliver sounds from the very quiet to the bombastically loud in full detail so listeners can really pick out the subtleties in their track.
Whether or not you’ll hear the differences in high bitrates and dynamic range between competing products will depend entirely on your own ear, but coming from integrated audio, there is a noticeable bump in quality that can be perceived right away. The lack of distortion and line noise makes audio sound cleaner and more defined. Details are more easily heard. It’s not an exaggeration to say that the Onyx and a good pair of headphones will let you hear things you haven’t heard before if all you’ve experienced is built-in DAC/amps.
Another big reason for this is the sheer amount of power it’s able to deliver. An average consumer headphone from Sony, Razer, or Skullcandy will typically fall between 16-32 ohms of resistance, so it doesn’t need much power at all. The higher the ohm rating, the more power is required to drive that headphone. (Ninja’s Beyerdynamic DT-990 Pros, for example, can go all the way to 600 ohms, and require far more power to drive.) The Onyx is able to deliver 180mW into 22 ohms, which is much more powerful than most dongle DAC/amps (THX’s testing puts it 2-5x higher). The popular TempoTec Sonata HD Pro only puts out 60mW into 32 ohms, for example, and is considered quite powerful by dongle standards. The Onyx is so much more powerful, in fact, it’s powerful enough to run a reasonable set of desktop speakers.
Because of its high power output, THX asserts that it can drive headphones up to 600 ohms. I didn’t have a pair of 600 ohm cans to test with (they’re not common), but the Onyx was able to push my Sennheiser HD-6XXs at 300 ohms to uncomfortably loud levels. That is downright remarkable from a device this size and makes this unit quite a compelling buy for audio enthusiasts on the go.
To go along with all this power, THX has equipped the Onyx with the ability to decode high-resolution audio format like MQA and DSD. Tidal users in particular will care about MQA, which stands for Master Quality Authenticated, as it’s the service’s current claim to fame: studio master quality audio. DSD, or Direct Stream Digital, on the other hand, is a high resolution file format popular among audiophiles. The device isn’t limited to these formats, however, as it will also decode standard and high resolution audio files. The type of file being played is indicated with a helpful series of LEDs on the unit’s body.
Finally, the Onyx also supports microphone use. I was easily able to plug in my Razer Blackshark V3 gaming headset and chat with friends over Discord. That also makes the device useful for Google Meets and other conference calls when working from home.
THX Onyx – Performance
Since the Onyx is a multipurpose device, I tested it with a wide range of headphones. The Razer Blackshark V3 was used for gaming. I also tested it with my Sennheiser HD-6XX, HD-58X, and HD560S, as well as the Audeze LCD-1, and BeyerDynamic DT-177X GO, as well as a handful of different IEMs. I feel confident in saying that the Onyx has enough oomph to drive just about any headphone you’d like to throw at it, though still doesn’t quite replace a desktop amplifier and DAC setup.
For gaming, I was very impressed at how much better the Blackshark V2 sounded. Like most gaming headsets, it doesn’t need external amping and will get plenty loud when plugged directly into a PC or controller. The Blackshark just goes to show that using a device like the Onyx isn’t all about volume. Compared to the sound output by the Gigabyte AORUS X570 Master motherboard — which boasts about its built-in audio — the Onyx offered a more detailed sound. Playing Doom Eternal, I was able to pick out every layer in the sound mix, even during intense battles where the heavy metal soundtrack roars through the rip and tear of it all. Being able to hear those details raised my positional awareness, so when an imp started taking potshots, I could tell where they were by sound alone.
That detail also paid off in Battlefield 5. The exceptional dynamic range and clean, distortion-free audio allowed me to pick out tiny details that usually get lost mid-battle. The sound of spent casings hitting the floor, interspersed with breaking, tinkling glass clearly stood out even while grenades were exploding and gunshots reverberated through the hallway in one particularly memorable battle. And through that, I could clearly hear more enemy players stomping up the stairwell to root us out.
At its core, the Onyx is an audio-enthusiast’s product and that’s where it really shines. This is a door-opening product. None of my other dongles have allowed me to take my HD58X out of the house and feel like I’m getting the full quality they have to offer. As a 150 ohm headphone that’s also fairly sensitive, they’re not hard to drive but absolutely sound best when they have more power and the Onyx just delivered. Bass was tight, music was textured, and there was lots of low-level detail that really made it feel alive.
I listen to a good mix of rock, electronica, and blues. For this testing, I listened through Tidal using MQA. The feed-forward error correction really paid dividends when it came to detail and clarity. Without that distortion, I was able to make out tiny details, like the oscillating texture of synths or how the drummer would strike a cymbal. Electronic music also took on an added depth and offered a greater sense of space. With the added output headroom, the drivers in my different headphones were able to pull what they needed and respond wonderfully. This was especially present in the bass response of the Audeze LCD-1, which was bigger and more detail-rich than any dongle amp I’ve tried, or even my GoXLR Mini, has been able to produce. To my ear, it’s closer to the Fulla 3 mini desktop amp from Schiit Audio, despite that amp being much more powerful.
The only exception was with my Sennheiser HD-6XXs, which were also the hardest to drive of my assortment of headphones. The Onyx allowed them to sound good but at 300 ohms, that headroom starts to diminish some and tiny details, like how tightly the bass responds, sounded a bit softer to my ear.
These improvements also apply to other kinds of media. The combination of the excellent DAC and the drivers being flush with energy make movies sound great. Again, it’s about the low level detail and clarity. You can simply hear more. The grain in the voice of Heath Ledger’s Joker, for example, took on a new crispness in The Dark Knight.
Given the level of power it puts out, you would be right to wonder about battery life. Thankfully, the Onyx is quite efficient. Using the Sennheiser HD560S, which is harder to drive at 120 ohms, I averaged only 10% battery loss in an hour of listening with intermittent screen time to change playlists. I was also running the headphones at a fairly loud 70%. With a more efficient pair of headphones, this would likely be even less, but I was impressed. The Khadas Tone 2 Pro sucked up 50% more power with the same settings.
If it sounds like these are small improvements, you would be right, but it’s the small details that add up to something big. When I first tried the Onyx, I was most impressed by how powerful it was and then enjoyed the sound. It clearly sounded better, but it was only when I went back that I started to notice that my integrated audio lacked that touch of clarity, even on headphones it should easily drive. The Onyx isn’t just about volume, though. It’s about being able to drive virtually any pair of headphones with headroom to and error-correction to really let them sound their best no matter where you are.
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