The march away from the 3.5mm headphone jack has left us in a world cluttered with dongles, each one a fragile, easy-to-lose link between our phones and decent sound. For a while, the solution was a dedicated USB-C DAC dongle, but that just adds another bulky piece to the puzzle. We’re now seeing the next logical step in this evolution: integrating the DAC and amplifier directly into the earphone cable itself. It’s a cleaner, smarter approach, and few companies are better positioned to tackle this than Hidizs, a brand that consistently delivers audio gear that punches well above its price tag.
Enter the Hidizs ST2 Pro. This isn’t just another budget-friendly in-ear monitor; it’s a complete audio system disguised as a simple pair of earphones. The real star of the show is the “Nebula” cable, which houses an ESS ES9281AC PRO DAC chip right inside its transparent USB-C connector. This isn’t some generic, off-the-shelf component; it’s a capable chip that supports high-resolution audio up to 32-bit/384kHz, DSD128, and even MQA unfolding. It also pushes a respectable 70mW of power, which is plenty for the included earphones and most other sensitive IEMs you might want to pair it with.
The earphones themselves feature a 10mm dynamic driver tucked into a lightweight, custom-like resin shell, tuned to the popular H-2019 target curve for a fun, engaging sound. You get the see-through aesthetic that’s all the rage, a well-made braided cable with an in-line microphone, and a solid set of accessories.
What makes this whole proposition so compelling is the price. While it had an aggressive launch on Kickstarter, the full ST2 Pro kit has now settled into its street price, and you can regularly find it on AliExpress for around $60, give or take. You can even snag the Nebula DAC cable on its own for under $40, which is a killer deal for anyone who already has a favorite pair of 2-pin or MMCX IEMs. The real question is, does this clever, all-in-one package actually sound as good as the specs suggest? Let’s dive in and find out.
A Closer Look at the Design and Build
The ST2 Pro earphones themselves are crafted from a skin-friendly, transparent resin, giving you a clear view of the 10mm dynamic driver inside. It’s a look that feels modern and techy without being over the top. The shells have a custom-like ergonomic shape that fits snugly and comfortably in the ear, providing a good amount of passive noise isolation. At just 7 grams each, they are incredibly lightweight, making them perfect for long listening sessions without any fatigue.
The real star of the show, however, is the Nebula cable. This is what sets the ST2 Pro apart from the competition. The USB-C connector features a transparent window showcasing the internal circuitry, including the impressive ESS ES9281AC PRO DAC chip. This is the brain of the operation, handling all the digital-to-analog conversion.
A handy LED indicator lights up red for standard-quality audio and blue for high-resolution PCM or DSD playback. The 1.2-meter cable is wrapped in a woven textile material that feels durable yet remains soft and flexible, minimizing microphonic noise. It’s a well-thought-out design that feels much more premium than its price tag suggests.
The Sound: How Does It Actually Perform?
Plugging the ST2 Pro directly into my phone, the first thing I noticed was the sheer power and clarity. The sound signature is tuned to the popular H-2019 target curve, which translates to a fun, dynamic, and engaging listening experience that works well across a huge variety of music genres.
The Bass Breakdown
The low end on the ST2 Pro is big, bold, and incredibly satisfying. There’s a generous emphasis on both the sub-bass, which provides a deep rumble, and the mid-bass, which delivers a powerful punch. Listening to tracks like Drake’s “Nonstop,” the bass hits with authority and impact that you can feel. What’s impressive is that despite its quantity, the bass remains well-controlled. It doesn’t sound muddy or bleed excessively into the midrange, a common flaw in many budget earphones. It’s not a bass-head’s IEM in the traditional sense, but it provides a rich and physical low-end that makes modern music come alive.
Mid-Range Clarity
For a V-shaped tuning, the mid-range is surprisingly present and clean. Vocals and instruments don’t feel distant or hollowed out. They come through with good definition and a natural timbre. While a hardcore audiophile might point out a lack of ultimate refinement or texture in the mids, for everyday listening, they are fantastic. Voices are clear, and the sound is harmonious without any harshness.
Treble and Detail
The treble is energetic and extended enough to provide a nice sense of air and detail. It adds a touch of brightness to the sound that keeps things exciting and prevents the presentation from feeling dark or dull. Crucially, it manages to do this without becoming sharp, sibilant, or fatiguing over time. Cymbals have a nice shimmer, and high-frequency details are easily discernible.
Soundstage and Imaging
The soundstage is respectably wide and spacious for an in-ear monitor in this price category. It doesn’t feel congested or claustrophobic, and the imaging is good, allowing you to place instruments within the stereo field accurately. While it may not have the vast, holographic presentation of much more expensive IEMs, it creates a coherent and immersive listening space.
The Nebula DAC Cable:
One of the most compelling aspects of this package is the ability to buy the Nebula DAC cable separately in either 2-pin or MMCX variants. This cable is a phenomenal upgrade for any compatible IEM. I tested it with my Dunu Kima and Hidizs MP145, and the results were excellent. The cable has a neutral and balanced sound signature with a touch of sparkle, and its 70mW of power is enough to drive most sensitive IEMs with authority.
It offers a significant step up in quality compared to the basic codecs found in most smartphones or generic dongles. It’s an incredibly convenient way to get high-quality sound on the go without the bulk of a separate DAC, and it consumes very little power from your phone’s battery. The fact that you can get this level of audio performance from a simple cable is truly a game-changer.
Practical Performance for Daily Use
Beyond music, the ST2 Pro is a versatile performer. The wired USB-C connection means there is zero latency, making it a fantastic choice for watching movies or gaming where audio sync is critical. The built-in HD microphone is also surprisingly clear for phone calls, with people on the other end reporting that my voice came through perfectly. The simple one-button in-line remote allows you to play, pause, and skip tracks, adding another layer of convenience.
The Final Verdict
The Hidizs ST2 Pro doesn’t just meet expectations for its price; it completely shatters them. You’re getting a pair of well-tuned, comfortable earphones and a high-performance DAC cable for the price of what some brands charge for a basic dongle. It is a brilliant, all-in-one solution for anyone looking to seriously upgrade their mobile audio without a lot of hassle or expense.
This is the perfect entry point for someone curious about high-fidelity audio, and it’s also an excellent choice for seasoned listeners who want a convenient, high-quality setup for their commute or travel. The sound is fun and powerful, the design is smart and practical, and the value is simply off the charts. The ST2 Pro is an absolute recommendation and a testament to how good budget audio has become.
