If you want waterproof gaming headphones for children that let them stay safe while swimming or running outdoors, choose FJX Bone Conduction Headphones; if you need crystal clear calls sleep headphones for children in a quiet environment with immersive music and noise isolation, choose TANCHJIM MINO ASANO Tench.
These two products sit at opposite ends of the audio spectrum. One is built to keep your ears open to the world while you move through water and wind; the other is designed to shut out the chaos and deliver studio-grade sound into your personal sanctuary.
• FJX Bone Conduction Headphones: Its biggest strength is the IP68 waterproof rating and open-ear design that keeps users aware of their surroundings, making it ideal for active outdoor play; its trade-off is that it lacks deep bass and requires MP3 mode for underwater use since Bluetooth does not work below the surface.
• TANCHJIM MINO ASANO Tench: Its biggest strength is the Active Noise Cancellation (ANC) and Hi-Fi dynamic driver that delivers rich, immersive sound with up to 37 hours of total battery life; its trade-off is the in-ear design which blocks external sounds and is only IPX4 rated, limiting it to light sweat or rain rather than full submersion.
• Who each pick is for: The FJX is perfect for parents looking for comfortable open ear earbuds for children who love swimming and sports, while the TANCHJIM suits those prioritizing high-fidelity audio, long battery life, and noise isolation for travel or study.
The FJX Bone Conduction Headphones are engineered for a specific type of user: someone who needs to hear what is happening around them while still enjoying audio. This is not just a safety feature; it is a fundamental design choice that changes how a child interacts with their environment. Because these headphones utilize bone conduction technology, they transmit sound vibrations directly through the cheekbones to the inner ear, leaving the ear canal completely open. For a child playing outside, this means they can listen to their favorite tunes while remaining fully alert to traffic, wildlife, or friends calling out to them. This makes them an exceptional choice for any parent worried about safety during outdoor activities like running, cycling, or hiking.
We compare products from their published specs and features; the verdicts below are our independent editorial opinions.
Updated: 2026-10-24 · 7 min read · Independent comparison
The standout feature here is the IP68 waterproof rating. Unlike standard earbuds that might survive a splash, these are built to withstand full submersion. A child can take them snorkeling, fishing, or boating without fear of damage. However, there is a crucial operational detail to understand: while the device is waterproof, Bluetooth signals do not travel well through water. Therefore, for the best swimming experience, the user must switch to the built-in MP3 mode using the 32 GB internal storage. This allows the headphones to function as a standalone music player, ensuring uninterrupted audio even when the child is fully submerged. This dual-mode capability—Bluetooth for land and MP3 for water—is a unique advantage that few competitors offer.
Comfort is another pillar of this design. Weighing in at only 29 grams and constructed from ultra-light titanium, the headset is ergonomically shaped to fit snugly behind the ears without causing pressure points or swelling during long wear. This is vital for younger users who might fidget or remove uncomfortable gear after a short time. The inclusion of special earplugs further enhances the swimming experience by reducing water noise entering the ear canal, allowing the bone conduction vibrations to be heard more clearly. If your child is an active swimmer or runner who refuses to wear traditional in-ear devices, the FJX offers a robust, durable solution that prioritizes both safety and enjoyment.
The TANCHJIM MINO ASANO Tench serves a completely different purpose. It is built for immersion. Whether your child is trying to focus on homework, sleep, or simply wants to get lost in a podcast or game, the Tench provides a sonic shield against the world. The defining feature here is the Active Noise Cancellation (ANC), which actively reduces environmental noise by up to -45dB. In a noisy household, on a bus, or in a busy classroom, this feature allows a child to create a quiet bubble of their own. The ENC (Environmental Noise Cancellation) technology further ensures that voice calls remain crystal clear, suppressing background chatter so conversations are never interrupted by static or ambient noise.
Sound quality is where the Tench truly shines compared to the FJX. It utilizes a 10mm beryllium-coated dome dynamic driver, which produces a wide dynamic range with minimal distortion. This results in smooth ultra-high frequencies, a balanced midrange, and deep, punchy bass. For audiophiles or children who enjoy gaming and watching videos, this level of fidelity creates a much more engaging experience than bone conduction. The low latency of 0.086 seconds in Game Mode ensures that audio stays perfectly synchronized with video, eliminating the lag that can ruin competitive gaming or make cartoons feel disjointed. This makes the Tench an excellent choice for crystal clear calls sleep headphones for children who need to relax or concentrate without distraction.
Battery life is another massive win for the TANCHJIM. With up to 6 hours of playback on a single charge and a total of 37 hours including the charging case, these earbuds can last nearly a week for an average user before needing a top-up. They also support wireless Qi charging, adding convenience to the mix. While they are only IPX4 rated, meaning they handle sweat and light rain well, they are not designed for swimming. The in-ear design, while isolating, requires the user to wear silicone tips. If your child prefers a secure, in-ear fit that blocks out the world rather than one that leaves them exposed to it, the Tench is the superior technical package for daily listening and media consumption.
• Best for swimming and water sports → FJX Bone Conduction Headphones. The IP68 rating and dedicated MP3 mode allow for full underwater use, whereas the Tench is only water-resistant to light splashes.
• Best for noise isolation and focus → TANCHJIM MINO ASANO Tench. The ANC capability blocks out distractions, creating a private listening space that the open-ear FJX cannot provide.
• Best for outdoor safety awareness → FJX Bone Conduction Headphones. The open-ear design ensures your child hears approaching cars or people, a critical factor for active kids.
• Best for long battery life → TANCHJIM MINO ASANO Tench. Up to 37 hours total playback far exceeds the FJX's 4-hour battery life per charge.
• Best for high-fidelity audio and bass → TANCHJIM MINO ASANO Tench. The 10mm dynamic driver delivers a richer, deeper sound profile suitable for music lovers and gamers.
• Best for lightweight comfort during long runs → FJX Bone Conduction Headphones. At 29 grams with no in-ear tips, they eliminate the feeling of "plugged" ears and reduce fatigue.
• Best for gaming with zero lag → TANCHJIM MINO ASANO Tench. The 0.086-second low latency ensures perfect sync between video and audio, essential for mobile gaming.
• Best for all-day durability in harsh weather → FJX Bone Conduction Headphones. The rubberized construction and IP68 protection handle rain, dust, and submersion better than the plastic Tench.
In my opinion, the choice depends entirely on the lifestyle of the child. If I were buying for a young athlete who swims regularly or plays outside frequently, I would unhesitatingly choose the FJX Bone Conduction Headphones. The ability to swim with music while staying safe is a feature that simply cannot be ignored, and the ultralight design ensures they won't bother the child during long workouts. However, if the goal is to help a child focus, sleep, or enjoy high-quality entertainment in noisy environments, the TANCHJIM MINO ASANO Tench is the clear winner due to its superior sound quality and noise cancellation. For a child who needs comfortable open ear earbuds for children to stay connected to the world, the FJX remains the specialized tool that fits that specific need perfectly.
Yes, the FJX Bone Conduction Headphones are IP68 waterproof and safe for swimming, provided you use the internal MP3 mode since Bluetooth signals do not transmit underwater. The TANCHJIM Tench is only IPX4 rated and should not be submerged.
The TANCHJIM MINO ASANO Tench offers significantly better sound quality with its 10mm dynamic drivers and Active Noise Cancellation, providing deeper bass and a more immersive experience than the FJX bone conduction model.
The TANCHJIM Tench lasts up to 37 hours with the charging case, while the FJX Bone Conduction Headphones offer approximately 4 hours of continuous playback on a single charge.
You will need the TANCHJIM app to customize equalizer settings and touch controls for the Tench, whereas the FJX uses simple physical multi-function key presses to switch modes without requiring a smartphone app.
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