How We Research
We compare products from their published specs and features; the verdicts below are our independent editorial opinions.
If you want a complete, ready-to-wear set of deep bass earbuds with a charging case and rugged protection — and you want something simple to live with, which matters a lot for seniors — choose JVC XX True; if you need to upgrade the sound of wired in-ear monitors you already own, with a stainless-steel-core tip that tightens bass and opens up the stage, choose AZLA Mithryl IEM Ear. Those are two very different jobs, and picking the wrong one is the most common mistake I see people make in this corner of the market.
• JVC XX True — biggest strength: A self-contained true wireless system tuned for extreme deep bass, with up to 24 hours of total battery life and auto-connect the moment you lift the buds out of the case.
• JVC XX True — biggest trade-off: No active noise cancellation and no wired jack, so its isolation depends entirely on how well the earpieces seal in your ears, and there's no cable fallback when the battery runs down.
• AZLA Mithryl IEM Ear — biggest strength: A precision-machined surgical stainless steel core that reduces vibration loss for more accurate reproduction and better detail retrieval, plus a secure silicone seal for stronger passive isolation.
• AZLA Mithryl IEM Ear — biggest trade-off: These are replacement ear tips, not earbuds, and they're explicitly not for TWS — so they will not help a wireless pair, and they do nothing at all on their own.
• Who each is for: JVC XX True is for someone who wants one box, one charge, and a bass-forward sound with no setup beyond Bluetooth pairing. AZLA Mithryl is for someone who already owns wired HiFi IEMs and wants to change how they sound and fit.
The XX True is built around one idea: push the low end as far as a compact true wireless bud can go. JVC tunes these specifically for what it calls extreme deep bass, with a dynamic driver covering 20 Hz to 20,000 Hz and a low 16 ohm impedance. That low impedance figure is worth noticing — it means these are easy to drive from a phone or tablet without any extra amplification, which is exactly what you want from a wireless everyday pair.
The practical side is where it earns its place. Battery life runs up to 24 hours total with the included charging case, and a full charge takes about 1.5 hours. Take the buds out and they power on and connect automatically. Each earpiece weighs just 4.4 grams, so the rounded-tip design stays light in the ear over long stretches — good news if you wear earbuds for hours of podcasts, audiobooks or music rather than ten-minute bursts.
Then there's the durability story. JVC calls it the "Big 3 proof": a rubber protector for shock resistance plus IP55-rated water jet and dust protection. That combination makes these a sensible pick for workouts, yard work or damp weather. If you've been hunting for sweat-resistant gear you can wear while moving, these are designed with that kind of use in mind. Bluetooth 5.3 and voice control (including Siri) round things out.
Who should skip it? Anyone who needs active noise cancellation, a wired option, or a neutral, analytical sound signature. There's no noise control here at all, no headphone jack, and the tuning is deliberately bass-heavy rather than flat.
This is a completely different kind of product, and it's important to be clear about that up front: the AZLA Mithryl is a set of ear tips — two of them — not a pair of earbuds. They're designed to replace the stock tips on wired HiFi in-ear monitors. AZLA states plainly that they are not for TWS, so if you were hoping to improve a wireless pair, this isn't the product for that.
What makes them interesting is the construction. Instead of an all-silicone tip, each one has a precision-machined surgical stainless steel core. The idea is that a rigid core loses less vibration than soft silicone alone, which translates into more accurate sound reproduction and better retrieval of fine detail. In practice that's the classic recipe for tighter, better-controlled bass and a more spacious sound stage — the low end gains definition rather than just volume, and highs come through clearly instead of smearing.
The other half of the story is fit. The ergonomic silicone shape is meant to create a secure seal, which improves passive noise isolation — the kind you get from blocking your ear canal, not from electronics. AZLA also emphasizes long-lasting comfort for extended listening sessions, and the silicone is certified premium and hypoallergenic, meeting EU RoHS and REACH standards. The smooth surface wipes clean easily, which matters if you use IEMs daily.
Who should skip them? Anyone without wired IEMs. If you don't already own a pair of wired in-ear monitors, these tips have nothing to attach to, and there is no warranty listed for them either.
• Best for a complete, no-extras-needed setup → JVC XX True. It's a finished product: buds, charging case, cable, eartips, all in the box.
• Best for upgrading sound you already own → AZLA Mithryl IEM Ear. It only makes sense if you have wired HiFi IEMs to put them on.
• Best for battery life and untethered listening → JVC XX True. Up to 24 hours total with the case, and roughly 1.5 hours to recharge.
• Best for isolation → AZLA Mithryl IEM Ear. Its whole design brief is a secure silicone seal for passive noise isolation, since the JVC pair has no noise control at all.
• Best for bass quantity → JVC XX True. The tuning is explicitly built for extreme deep bass, with a dynamic driver reaching down to 20 Hz.
• Best for bass control and detail → AZLA Mithryl IEM Ear. The steel core is there to cut vibration loss and sharpen accuracy, which cleans up the low end rather than inflating it.
• Best for rough handling and sweaty use → JVC XX True. Shock protection plus IP55 water-jet and dust resistance are built in; the AZLA tips are silicone and best treated as a delicate accessory.
• Best for easy maintenance → AZLA Mithryl IEM Ear. The smooth hypoallergenic silicone surface is simple to wipe down after every session.
If I were buying for myself and I wanted one product that just works — pull it out, it connects, the bass hits, and it survives being knocked around — I'd take the JVC XX True. The 24-hour total battery, 4.4-gram earpieces, auto-connect and IP55 build make it the easier, lower-fuss choice, and for seniors especially, the lack of setup and the lightweight fit are real advantages. I'd only go with the AZLA Mithryl if I already owned wired IEMs and wanted to reshape their bass and staging — in that specific case, in my opinion, the steel-core design is the more interesting buy. Check the current price on Amazon before you commit, since that's the one thing that can tip a close call.
It describes earbuds deliberately tuned to emphasize low frequencies — the rumble and punch in music. The JVC XX True fits that description directly, with special tuning for extreme deep bass and a dynamic driver rated from 20 Hz to 20,000 Hz.
It depends on what you listen to. Heavy low-end tuning is great for hip-hop, electronic and action-heavy media, but it colours the sound rather than reproducing it flat. If you want accuracy instead of emphasis, the AZLA Mithryl's steel-core design aims at tighter, more detailed bass.
The honest answer is that you can't add bass a driver can't produce. You can raise the low frequencies in your phone's equalizer, or improve the seal so you hear more of what's already there — which is exactly what the AZLA Mithryl silicone tips are designed to do with a secure, isolating fit.
For movement, durability and fit matter more than tuning. The JVC XX True is the one built for it here: shock protection, IP55 water-jet and dust resistance, 4.4-gram earpieces and Bluetooth 5.3. The AZLA Mithryl tips aren't a sports product — they're a fit-and-sound upgrade for wired IEMs.
As an Amazon Associate I earn from qualifying purchases.
We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon and affiliated sites.
When you buy through links on this page, we may earn a commission from qualifying purchases at no extra cost to you.
Amazon and the Amazon logo are trademarks of Amazon or its affiliates. This site is an independent third-party review and is not affiliated with, endorsed by, or sponsored by Amazon or the product brands mentioned.
See also: ZIYOU LANG 61 vs HEGMUXCO Computer Speakers: RGB Gaming, TINHIFI C1 vs ICESOMNUS Sabbat E12: 10mm Driver Earbuds, Hercules HDP DJ45 vs YLFASHION Icarer Kids, Sennheiser HD 280 vs Cambridge Audio Melomania A100