HIDIZS ST2 PRO Review - Ian Banzuelo

Hidizs ST2 PRO Nebula 

A Compact Innovation for Ultra-Mobile Audio

Pros:

Innovative DAC Cable: The ES9281AC PRO-powered cable delivers excellent audio performance while doubling as a portable DAC.

Impressive Sound Tuning: A slightly tweaked Harman curve offers a fun, engaging, and versatile sound profile.

VR Gaming Star: Excels in spatial audio and imaging, creating an immersive gaming experience.

Ultra-Portability: Combines the convenience of a dongle and IEM cable into a compact, lightweight package.

The Hidizs ST2 PRO Nebula is a bold step forward in the IEM space, blending the simplicity of a single dynamic driver with the power of a high-performance DAC cable. At first glance, it may look like just another Type-C IEM package, but a closer look reveals a game-changing feature: the cable itself doubles as a fully-fledged DAC. Powered by the ES9281AC PRO chip (found in full sized dac devices like the Astell&Kern AK-HB1 and Fiio KA1), the ST2 PRO delivers an impressive 70mW of power, proving that big things do come in small packages, and i do believe this is the next innovative step to the ultra portable setup.

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Design & Build Quality

The ST2 PRO Nebula’s design strikes a balance between form and function. The cable showcases an aluminum alloy USB connector, with transparent windows on either side to reveal the internal PCB. A small LED indicator provides real-time feedback on audio sampling rates—red for PCM (44.1-48kHz) and blue for PCM (88.2-384kHz) or native DSD playback.

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Hidizs has tuned the ST2 PRO Nebula to a slightly tweaked Harman curve, creating a sound profile that's fun, engaging, and surprisingly versatile. One area where this tuning truly shines is gaming. For me, the ST2 PRO feels tailor-made for immersive gameplay. Paired with my MetaQuest 2 VR goggles, it delivers exceptional spatial audio performance. The 3D soundscape is impressively detailed, with precise imaging that places every sound exactly where it should be. It wraps you in a fully immersive audio environment, making every gaming session feel incredibly lifelike and engaging.

Bass

The subbass on the ST2 PRO Nebula is generous, it deep and resonates delivering a satisfying rumble that adds depth and weight to tracks, particularly in genres like electronic, hip-hop, or cinematic scores. ... ...

Midrange

The mids maintain a natural timbre and tonal accuracy, which helps them feel lifelike and engaging. ... ...

Treble

The treble performance is a standout feature of the ST2 PRO Nebula. Energetic and well-extended, the highs bring a sense of air and sparkle to the overall sound signature. ... ...

The soundstage is average in width and depth, providing a focused, intimate listening experience rather than an expansive one. Imaging is precise, making it easy to pick out instruments and positions in the mix.

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DAC Cable Performance:

The integrated DAC cable is where the ST2 PRO truly shines. Equipped with the ES9281AC PRO chip, the cable delivers enough power to drive even demanding planar IEMs without breaking a sweat. It handles volume adjustments smoothly, with plenty of headroom to spare.

What’s impressive is the level of portability this DAC cable brings. It bridges the gap between traditional USB dongles and standard IEM cables, offering the same performance as many dongles while remaining far more compact. For ultra-mobile audiophile setups this is a game-changer.

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Final Thoughts:

The Hidizs ST2 PRO Nebula showcases just how far compact audio solutions have come. It’s a versatile IEM that combines great sound with innovative DAC technology, all in a package that’s as portable as it is powerful. Personally, I’d choose this kind of ultra-portable setup over a full-sized USB dongle DAC any day. Plus, I’ve finally found a use for that included Hidizs leather pouch—it’s perfect for carrying this setup around.

For an IEM that delivers stellar sound quality, impressive DAC capabilities, and unmatched portability, the Hidizs ST2 PRO Nebula is a tough contender to beat at its price.

BUY NOW: HIDIZS ST2 PRO Nebula

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