Review of the JBL/UA FLASH-PROJECT ROCK Dwayne "The Rock" Johnson Special Edition

[PConline Review Lab] If you’ve visited any audio or headphone expos in recent months, you might have seen a poster like this—

　　JBL, which has long collaborated closely with the renowned sportswear brand Under Armour (hereinafter referred to as UA), has recently taken their partnership a step further by inviting Dwayne "The Rock" Johnson to join them in a triple collaboration. The result is the JBL/UA TRUE WIRELESS FLASH-PROJECT ROCK truly wireless earbuds (hereinafter referred to as ROCK). Such a three-way collaboration likely stems from the very successful partnership between JBL and UA. Indeed, looking at sales records on e-commerce platforms, JBL and UA’s co-branded products show clear advantages over others in the same price range. This suggests that this collaboration is not just about flexing strength, but also about gradually establishing themselves as leaders in the “truly wireless” space.

　　So, does wearing these earbuds during a workout suddenly make you feel like a “real man”? Fortunately, the PConline Review Lab recently got our hands on a pair, so we put them on for a test and are here to share our experience.

　　Appearance Details: Masculine Energy Meets Tech Aesthetics

　　Those familiar with The Rock know his co-branded products often feature a gold bull head, and this charging case is no exception. The elongated case is made of aluminum, with finely executed gold sandblasting and detailing that gives it a high-end look. Once again, I personally really like this elongated, drawer-style case. Compared to the more common flip-top cases, this design is less prone to accidental openings, and the push-pull mechanism gives it a distinctive feel.

　　The top of the battery case is equipped with a metal clasp that includes a built-in safety lock—very rugged in style. From a design aesthetics perspective, this clasp aligns with the overall tone of the earbuds while also being quite practical. You can use the clasp to hang the earbuds on your waistband, backpack, or any other place you can hook them onto. Additionally, the clasp functions as a “pull tab,” making it easy for users to quickly retrieve the earbuds from a bag or pocket.

　　Open the case, and you’ll see the two earbuds nestled in their respective slots. The all-black earbuds feature a striking yet not overly obtrusive gold bull head on the panel—a nice design touch. This bull head isn’t just for show; it’s a physical button. Depending on how many times you press the left or right bull head, it triggers different functions. Just read the manual, and you’ll be up and running with seamless music enjoyment. That said, here’s a small suggestion for JBL: perhaps upgrade to touch buttons in the next iteration. Not only would that enhance the tech feel, but it would also help avoid accidentally pressing the button against your ear.

　　Feature Breakdown: Top-Tier IPX7 Waterproofing—Take It for a Swim

　　Aside from the thoughtful exterior design, the functionality of these earbuds is also worth mentioning. JBL has equipped the ROCK with biomimetic hearing technology, which allows you to activate ambient sound or clear call modes with a single tap. What do these features do? Clear Call lowers music volume and enhances voice clarity, making it easier to talk with workout partners. Ambient Aware lets you enjoy immersive music while still being aware of your surroundings, improving safety during exercise. For those who like to work out with earbuds, biomimetic hearing tech is quite useful.

　　And now, the main event: one of ROCK’s standout features is its UA Storm waterproof design, built specifically for sports and enhanced by new manufacturing techniques like one-piece molding and ultrasonic welding. These features give the earbuds an IPX7-level waterproof rating. As far as we know, that’s the highest waterproof rating achievable for earbuds—so not only sweat and rain, but you could even take these for a swim.

　　Besides the standard accessories, we were pleasantly surprised to find a compact portable case. Made from high-strength ABS material, the black case has an indentation that fits the earbuds perfectly. You might be as puzzled as we were about the purpose of this little box at first. But during one of my workouts with the ROCK, I realized its use—for instance, when you just want to temporarily set down your earbuds without charging them (since their battery life is already solid), the main charging case can feel a bit bulky. That’s when this portable case comes in handy...

　　Sound Test & Experience: Secure Fit, Pleasing Audio

　　Visually, the ROCK doesn’t succumb to some oddly stylized aesthetic because of The Rock’s involvement. Instead, thoughtful details set it apart from common truly wireless earbuds. So, how is the actual user experience? Let’s start with the “connection” aspect.

　　Like most truly wireless earbuds, the ROCK has a pairing process. The first time you connect to a phone, take out the right earbud from the case—it will power on and enter pairing mode. Then, turn on your phone’s Bluetooth and select “UA PROJECT ROCK TRUE WIRELESS” from the list. Next, take out the left earbud, and it will automatically sync with the right one. After the initial setup, the earbuds will automatically connect to nearby Bluetooth-enabled devices when taken out of the charging case.

　　The ear tips and wing tips are designed separately, both made from soft silicone. This modular design allows users to choose the most suitable sizes for their needs.

　　First impressions of the ROCK highlight two standout features for wearability. First, the weight is well-controlled—8.5g per earbud, totaling around 17g. Coupled with ergonomic design and JBL’s SPORT FIT technology, which offers flexible, sports-oriented ear wings and ear tips, the fit is snug and secure. In my tests, even when shaken hard enough to make myself dizzy, the earbuds stayed firmly in place—as long as the wing tips and ear tips are properly matched, they won’t fall off, making them ideal for workouts. Second, the earbuds have a skin-like coating that feels quite pleasant, enhancing comfort where the earbuds contact the ears.

　　Over the course of a week-long testing period, we’d like to give a quick nod to the ROCK’s signal stability. Across various scenarios including subways, buses, short high-speed rail trips, and daily commutes, we experienced only 3–4 disconnections—and even then, they were more like brief stutters than full drops. Signal latency was moderate; no noticeable lag when watching videos or dramas, and unless you’re playing graphics-intensive mobile games like PUBG, the latency is generally acceptable for most users. It seems JBL’s latest true wireless Bluetooth tech is quite capable.

　　The ROCK is outfitted with 5.8mm composite diaphragm drivers. It’s a bit of a shame that it uses Bluetooth 4.2, with support only up to AAC wireless transmission. As a brand with over 70 years of audio product development experience, JBL’s tuning is well-regarded by many. Having used JBL products in the past—like the FREE, T280TWS, and LIVE 200BT—despite differences in positioning or category, their tuning approach is noticeably consistent. And the JBL UA FLASH ROCK carries on that tradition. You might expect, given that it’s an American sports headphone co-branded with action star The Rock, that it would amplify signature traits like raw power and straight-line speed—making heavy bass its main theme.

　　But it’s a bit different. The ROCK stays true to its family’s “vibrant” tuning style, delivering energetic sound without leaning too heavily on the low end. It leans more toward a slightly bright and vivid tonal balance. To summarize: the highs are not dull—in fact, they can be quite bright—with moderate detail and smooth sibilance, striking a good balance between excitement and comfort. The mid-bass is restrained, maintaining good density and moderate thickness, while vocals aren’t overly forward or muddy. The soundstage is also wider than typical sports TWS earbuds, taking on an elliptical shape, with decent separation and imaging. The biggest benefit of this engaging tuning is that the strong bass doesn’t overpower the music’s natural beauty. It’s fatigue-free even during extended listening and retains the energy needed for workouts.

　　In terms of battery life, JBL claims the ROCK offers up to 5 hours on a single charge, with the case providing an additional 20 hours. Based on the numbers, the total of 25 hours is enough for about a week of regular use. To test this, we used the earbuds for about 8 hours a day, and they lasted for three days—largely in line with the manufacturer’s specs.

　　PConline Review Lab Conclusion: A Powerful TWS Sports Earbud

　　Attentive readers may notice that these earbuds are based on the JBL & UA jointly released FLASH model, with The Rock added as a secondary customization—there are still some minor differences compared to the standard version. Despite the rugged appeal, the JBL UA FLASH ROCK doesn’t fall into stereotypical “macho” aesthetics. Its tech-forward design showcases the decades of R&D expertise from both JBL and UA, reinforcing its identity as a sports-focused headphone.

　　In an increasingly competitive market, JBL’s continued launch of truly wireless products shows the major brand’s interest in this still-developing space. Compared to previous models, today’s consumers are more rational when buying truly wireless earbuds. Products like the JBL UA FLASH ROCK, which take a holistic approach to user experience, are bound to gain more attention and favor from consumers.