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We compare products from their published specs and features; the verdicts below are our independent editorial opinions.
Updated: 2026-09-24 · 6 min read · Independent comparison
• MHTEC 2-in-1 — biggest strength: a genuine 2-in-1 trick. Rotate the earcups and the headphones become a Bluetooth speaker, plus you get 3 EQ modes, TF card playback and a 3.5mm wired jack.
• MHTEC 2-in-1 — biggest trade-off: no active noise cancelling, only sound isolation, and battery life is modest compared to the FJHBL (the sheet lists 25 hours average life, about 6 hours in speaker mode).
• FJHBL Headphones — biggest strength: active noise cancellation rated up to 48dB, Hi-Res Audio, spatial sound and up to 60 hours of playtime with ANC off.
• FJHBL Headphones — biggest trade-off: wireless-only connectivity, so there is no 3.5mm fallback listed, and the 2-in-1 speaker mode simply does not exist here.
• Who each pick is for: MHTEC suits travellers, students and gift-buyers who want one device that does two jobs. FJHBL suits commuters, remote workers and gamers who want quiet and long runtime.
The MHTEC 2-in-1 is built around a single idea: one object, two jobs. In headphone mode you listen privately through dual 40mm dynamic drivers with 32 ohm impedance and a 20Hz–20,000Hz frequency range. Twist the earcups and it becomes a Bluetooth speaker you can put on a table so everyone hears. I have not come across many headphones that genuinely do that, and it is the reason this model exists.
Around that core idea sit practical extras. Bluetooth 5.3 gives you a stable connection up to roughly 10 metres (33 feet). There is a TF card slot so you can play music without a phone at all — handy on a plane or at the gym where you would rather leave the handset in your bag. Three EQ modes (Bass Boost, Balanced, High Definition) let you tilt the sound toward punch or clarity. Comfort comes from protein leather cushions, memory foam padding and an adjustable headband, and the whole thing weighs 230g.
FJHBL Headphones: Who It's For
The FJHBL Headphones attack the opposite problem. They are for people who want the world to go quiet. Active Noise Cancellation reduces ambient noise by up to 48dB, which is the headline number here and the main reason to pick this model. Around it, FJHBL adds Hi-Res Audio certification and 40mm large-aperture dynamic drivers, so the sound side is not an afterthought. Spatial sound adds a 360° effect that suits films and games more than podcasts.
Battery is the other big story. The sheet lists up to 60 hours with ANC off and roughly 40 hours with ANC on. That is a genuine week of commuting on one charge, and it is the single biggest gap between these two products. The detachable boom mic is a smart touch too — clip it on for calls or in-game chat, take it off when you just want to look normal walking down the street. The headphones fold flat and ship with a protective carrying case.
Who should buy it: commuters, open-plan-office workers, frequent flyers and gamers who need a mic. Who should skip it: anyone who wants a wired connection as a backup, because the sheet lists wireless Bluetooth only, and anyone who liked the idea of a speaker mode — there is no such feature here. The M12 Black is the only colour listed.
• Best for noise cancelling → FJHBL Headphones. Up to 48dB of active noise reduction versus sound isolation only on the MHTEC.
• Best for battery life → FJHBL Headphones. Up to 60 hours with ANC off, about 40 with it on, against roughly 25 hours on the MHTEC.
• Best for sharing music out loud → MHTEC 2-in-1. The rotating earcup speaker mode has no equivalent on the FJHBL.
• Best for calls and gaming chat → FJHBL Headphones. The detachable high-sensitivity boom mic beats a built-in mic for voice pickup.
• Best for wired fallback → MHTEC 2-in-1. A 3.5mm jack and an aux cable are included; the FJHBL sheet lists wireless only.
• Best for movies and games at home → FJHBL Headphones. Spatial sound plus Hi-Res Audio is aimed squarely at immersive content.
• Best as a gift → MHTEC 2-in-1. Premium carrying case, elegant retail packaging and a novelty factor that reads well when unwrapped.
My Verdict
If I were buying for myself, I would take the FJHBL Headphones. In my opinion, the combination of real active noise cancelling, up to 60 hours of playtime, spatial sound and a detachable mic covers more of what I actually do — commute, work, watch films — than a speaker mode I would use occasionally. The MHTEC 2-in-1 is the better pick if the 2-in-1 trick is the whole point for you, or if you want a wired jack and a gift-ready box. Decide which of those two lives sounds more like yours, then check the current price on Amazon before you commit.
what is 40mm driver in headphones
A 40mm driver is the circular speaker unit inside each earcup, measured across at 40 millimetres. Both the MHTEC 2-in-1 and the FJHBL Headphones use 40mm dynamic drivers, which is a common size for over-ear models because it moves enough air for solid bass without making the cups bulky.
is 40mm driver good for headphones
For over-ear headphones, yes — 40mm is a well-established size that balances bass output against weight and comfort. Both models here pair a 40mm driver with extra processing: the MHTEC adds three EQ modes, while the FJHBL adds Hi-Res Audio and spatial sound. The driver size is a starting point, not the whole story.
what are 40mm drivers in headphones
They are the paired speaker units that convert the electrical signal into sound, one per earcup. In the MHTEC they are described as dual 40mm dynamic drivers with a 20Hz–20,000Hz range and 32 ohm impedance; in the FJHBL they are 40mm large-aperture dynamic drivers tuned for Hi-Res Audio.
which driver is best for headphones
Bigger is not automatically better. A larger driver can push more bass, but tuning, impedance and the electronics around it matter just as much. Both products here use the same 40mm class of driver, so the real differences come from noise cancelling, EQ modes, battery and features — not from driver size alone.
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