Today we’re reviewing the OpenRock S2 earbuds, an intriguing sub-$100 offering from OpenRock. For the price, the S2 features an ergonomic ear-hook design, LDAC support, an IPX5 waterproof rating, and a quad-mic array with AI noise cancellation inside.
Disclosure: The S2 earbuds were provided by OpenRock for this review, but the company had no input on the content shared here. That said, OpenRock is offering readers a 20% discount (Code: TechPorn) for purchases made through their official online store.
Table of Contents:
Technical Specifications
The OpenRock S2 is a lightweight, open-ear sport earbuds featuring a pair of 12 mm transducers and Bluetooth 6.0 with support for LDAC. It has up to 8 hours of listening time on a single charge, with a total of 32 hours available from the charging case.
| Earphones | |
|---|---|
| Transducer | 12 mm, Dynamic |
| Frequency Response | 20-20,000 Hz |
| Impedance | 16 Ω |
| Sensitivity | N/A |
| THD | N/A |
| Connectivity | Bluetooth 6.0 (LDAC, AAC, SBC) |
| Microphone | |
| Transducer | MEMS |
| Polar Pattern | N/A |
| Frequency Response | N/A |
| Sensitivity | N/A |
| Dimensions | |
| Length | 71 mm |
| Width | 62 mm |
| Height | 27 mm |
| Weight | 58 g (total) |
Packaging and Accessories
The OpenRock S2 comes in frugal packaging, a stark contrast to the presentation of the OpenRock X, which is undoubtedly a more premium pair.
Scope of delivery are as follows:
- OpenRock S2 earbuds
- Charging case
- Documentation
Design, Build and Connectivity
The OpenRock S2 Open-Ear Sport Earbuds boast a unique ear-hook design, with the battery and button positioned at the end of the hook for improved balance and enhanced ergonomics. Each earbud is equipped with a 57 mAh battery, offering up to 8 hours of playback on a single charge.
The charging case boasts a sleek pebble-like design and efficiently secures and charges the OpenRock S2 with its built-in 450 mAh battery. It’s said to provide at least 24 hours of power, extending to 32 hours when combined with the earbuds. On that note, a 5-minute charge will provide the buds with an hour of use.
Ergonomics
The OpenRock S2 is incredibly light, weighing around 7 grams per earbud. Including the case, the total weight remains impressively light at just under 56 grams, comparable to a competitive gaming mouse.
The fit and comfort of the OpenRock S2 are excellent, and I find it superior to the bulkier OpenRock X, which has most of its electronics concentrated around the earpiece. This design offers much better balance, improved retention, and, naturally, enhanced fit and functionality.
Software
The OpenRock S2 supports the brand’s mobile app which can be downloaded from the official website, the Play Store, or the App Store. The app allows you to update firmware and check earphone stats, such as the battery levels of each earbud and the charging case. If your device supports LDAC, you can enable it through the app, but keep in mind that activating LDAC disables the option to connect the earbuds to multiple devices simultaneously.
Other standout features of the OpeRock S2 includes button remapping, a volume limiter, multiple preset options, and a simple equalizer.
Frequency Response
Frequency response analysis of the OpenRock S2 shows that presets behave almost identically, with the exception of a small dip between the bass and midrange at its Relax mode. As usual, earbuds do not conform to my in-ear target, and despite its misleading name, I find Boom mode the smoothest out of the bunch with a more manageable low-end energy and midrange output.
Overall, the measurements are decent, but similar to the OpenRock X, there’s a noticeable dip in energy in the midrange, starting at 600 Hz and continuing until 3 kHz. Once again, like the OpenRock X, we observed elevated energy in the treble, though it’s neither concerning nor represents what we’re actually hearing.
Bass
With Boom mode, the bass starts to taper off around 125 Hz and remains mostly within the target curve. Considering the OpenRock S2 is an earbud, the limited sub-bass is understandable.
Mids
The midrange performance is decent, but a noticeable dip between 600 Hz and 3 kHz reduces detail retrieval. The bass and lower midrange up to 500 Hz are well-balanced, though they occasionally add some coloration to the overall sound signature of the OpenRock S2. On the bright side, this tuning helps create a wider and more open soundstage.
Treble
As I mentioned before, the treble doesn’t align with how it looks on the graph. To me, it’s neither sharp nor sibilant; in fact, it’s the complete opposite with only a slight hint of brightness between 3 to 5 kHz. This points to a significant inaccuracy in my test within that frequency range.
Distortion
The Total Harmonic Distortion (THD) of the OpenRock S2 stays mostly below 1% throughout the audible range, except in the bass frequencies where it surpasses that and can peak as high as 10% at its worst.
CSD
I’m not sure if it’s fair to expect this much lingering energy from the OpenRock S2 in the 3 to 4 kHz range, as it’s clearly linked to the measured frequency response in that area. However, the frequency decay in the bass is manageable, even with the resonance.
Noise Isolation
The OpenRock S2 provides little to no noise reduction, and this is entirely intentional. As the name implies, its open-ear design is meant to keep you aware of your surroundings, a feature the brand strongly highlights.
Microphone
The microphone performance of the OpenRock S2 is decent but has notable flaws. It suffers from an excessive energy concentration between 100 Hz and 1 kHz, which can unintentionally amplify distant background noises, making it less ideal for calls requiring pro-level clarity.
Input Lag
Bluetooth input lag typically averages around 327 ms and can reach up to 469 ms – nearly half a second of delay, which is definitely noticeable. Using LDAC mode can help reduce this, so if your device supports this codec, it’s a good idea to enable it.
Final Thoughts
The OpenRock S2 carves out a compelling niche in the crowded sub-100 wireless earbud market by focusing on a specific user: the active individual who prioritizes situational awareness, comfort, and durability. It doesn’t try to be a master of all trades; instead, it excels at its intended purpose, delivering a feature set that punches well above its price tag.
Its greatest strengths lie in its exceptional design and ergonomics. The lightweight, balanced ear-hook construction provides a secure and comfortable fit that remains stable during vigorous activity, a clear improvement over bulkier designs. Combined with an IPX5 rating and a robust battery life of up to 32 total hours, the S2 is a reliable companion for long workouts, runs, and outdoor adventures. The inclusion of the LDAC codec is a surprising and highly welcome feature at this price point, offering a higher-fidelity listening option for those with compatible devices.
However, the S2 is a product of clear compromises, particularly in its technical performance. While the overall sound signature is pleasant and non-fatiguing with a wide soundstage, it won’t satisfy audiophiles. The noticeable dip in the midrange between 600 Hz and 3 kHz results in a loss of detail, and the high Total Harmonic Distortion (THD) in the bass, which can peak at 10%, is a significant sonic flaw. Similarly, the microphone performance is a mixed bag; while functional, its tendency to amplify background noise makes it less than ideal for important calls in busy environments. Lastly, with Bluetooth latency averaging 327 ms, these earbuds are not well-suited for competitive gaming or watching videos where audio-visual sync is critical.
Ultimately, the OpenRock S2 is an excellent value proposition for the right person. If your priorities are a secure fit, all-day comfort, and maintaining awareness of your surroundings during exercise or commutes, its weaknesses are easy to forgive. It is tailor-made for runners, cyclists, and gym-goers. However, if you are seeking critical listening, immersive noise isolation, low-latency gaming, or professional-grade call quality, you should look elsewhere. For its intended audience, the OpenRock S2 is an outstanding choice that delivers on its promises at a highly accessible price.
OpenRock S2 Open-Ear Sport Earbuds $98.99
Product Name: S2 Open-Ear Sport Earbuds
Product Description: The OpenRock S2 features an ergonomic ear-hook design, excellent battery life, an IPX5 water-resistance rating, and surprisingly high-end LDAC codec support.
Brand: OpenRock
Summary
The OpenRock S2 is an affordable, sub-$100 pair of open-ear sport earbuds designed for active users. They prioritize a secure, comfortable fit and situational awareness over audio purity.
Pros
- Lightweight, ergonomic ear-hook design provides superior balance and a secure fit for sports and active use
- Offers premium features like LDAC support and a comprehensive app at a sub-$100 price point
- Provides up to 8 hours on a single charge, with a total of 32 hours available from the case
- Features an IPX5 water-resistance rating, making it suitable for sweat and light rain
- Open-ear design intentionally allows you to hear your surroundings, which is ideal for outdoor safety
- Despite measurements, the high frequencies are non-fatiguing and free of sharpness
Cons
- Significant dip in the midrange reduces detail, and high distortion in the bass compromises sound quality
- Quad-mic array can amplify distant background noise, making it less than ideal for clear phone calls
- Significant input lag makes them unsuitable for watching videos or gaming
- Presets does not offer their intended listening experience
