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We compare products from their published specs and features; the verdicts below are our independent editorial opinions.
Updated: 2026-10-04 · 8 min read · Independent comparison
They're both "aptX HD" products on the spec sheet, which is exactly why shoppers keep mixing them up. But one is a headset and the other is a transmitter, and that difference decides everything.
• WAVEFUN Neckband's biggest strength: it's a complete listening solution — 30 hours of playtime per charge, aptX HD support, and a 10mm titanium-plated dynamic driver in a flexible Nitinol neckband.
• WAVEFUN Neckband's biggest trade-off: it's a wired-feel neckband design with sound isolation rather than active noise cancellation, and it charges over Micro USB rather than USB-C.
• Avantree Relay & SoundJet's biggest strength: it turns a 3.5mm AUX output into a Bluetooth 5.3 aptX Adaptive/HD stream and can feed two pairs of headphones at once.
• Avantree Relay & SoundJet's biggest trade-off: it isn't a headset at all — it makes no sound on its own, and it's explicitly not compatible with phones, car stereos or hearing aids.
• Pick WAVEFUN Neckband if you want one device to wear.
• Pick Avantree Relay & SoundJet if you already own good Bluetooth headphones and want to use them where only a headphone jack exists.
The WAVEFUN Neckband (model Wavefun Flex 3) is built around a simple idea: stay on your neck, always be ready. The flexible neckband uses Nitinol construction, which is the shape-memory alloy that lets the band bend and spring back instead of cracking — a genuinely useful trait if you toss your earbuds into a bag every day. When you're not listening, the magnetic earbuds clip together and the whole thing coils into a pocket without tangling. That magnetic + neckband combination is the reason this category still exists in a world of fully wireless buds: nothing to lose, nothing to misplace mid-commute.
Battery is the headline number. WAVEFUN rates it at up to 30 hours of listening time per charge, drawn from a 200mAh battery paired with a low-power audio SoC running at 6mA. A full charge takes about an hour. For anyone who charges overnight and forgets about it, that's a week of normal use between top-ups. It's the kind of figure that matters if you're the person who always seems to be hunting for a charging case.
Audio is where the aptX HD angle comes in. The Flex 3 supports aptX HD and standard aptX, and WAVEFUN describes a 24-bit end-to-end audio pipeline inside the processing chain. In plain terms, aptX HD is a higher-bitrate Bluetooth codec than the default SBC, so it's designed to pass more musical detail to the drivers — provided your phone or player also supports aptX HD. The driver doing the work is a 10mm titanium-plated dynamic diaphragm with 16 ohm impedance, which WAVEFUN says is tuned for stereo separation and precise bass rather than a muddy low-end thump. Titanium plating on a diaphragm is a stiffness trick: stiffer material moves more cleanly, which usually shows up as tighter bass and less smearing in busy tracks.
Who should buy it: commuters, gym-goers and frequent callers who want one pair of earbuds that lives around their neck, lasts days between charges, and supports aptX HD on a compatible source. Who should skip it: anyone who wants active noise cancellation (this is sound isolation, not ANC), anyone who refuses to carry a Micro USB cable in a USB-C world, and anyone who wants a fully wireless experience with no band at all. Bluetooth is listed as version 5 with a 10-meter range, and controls are physical buttons with volume control — worth knowing if you prefer taps over buttons.
The Avantree Relay & SoundJet R1 is a different animal entirely, and it's important to be clear about that before you buy the wrong thing. This is a Bluetooth transmitter, not a pair of headphones. It has no drivers, no ear tips, no band. What it does is plug into a 3.5mm AUX jack and broadcast whatever audio is coming through that jack to your Bluetooth headphones. The classic use case is an airplane seat's entertainment screen: you plug the Relay into the armrest jack, pair your own AirPods or Bose headphones, and watch the in-flight movie without wearing the airline's disposable cans.
The chipset is Qualcomm's, with aptX Adaptive and aptX HD support, and Bluetooth 5.3 for stability. That's the technical heart of the product and the reason it appears in "aptX HD" searches alongside actual headphones. Avantree leans on its 20 years of wireless experience here, and the compatibility list is broad: AirPods, Bose and all Bluetooth headphones. Two things to note, because they're easy to miss — it's not compatible with phones, car stereos or hearing aids, and it needs a 3.5mm AUX socket to work at all. A phone with no headphone jack is a non-starter.
The dual-headphone feature is the standout. You can connect two Bluetooth headphones to the same Relay at once and both listeners hear perfectly synced audio. On a long flight with a partner or a kid, that's the difference between sharing one earbud and actually watching something together. It's a niche feature, but in that niche it's genuinely hard to replace.
Battery is rated at up to 25 hours of continuous playback, with LED indicators for connection status and onboard buttons for pairing and volume. The whole thing is lightweight and pocket-sized — the kind of accessory that lives in a travel pouch and gets forgotten until you're 30,000 feet up and the seat-back screen is the only entertainment available. Avantree also pitches it for gym sessions, which makes sense: older cardio machines with 3.5mm outputs can feed your own headphones through it.
Who should buy it: frequent flyers, anyone with a decent pair of Bluetooth headphones and a stubbornly analog audio source, and couples or families who want to share one screen. Who should skip it: anyone shopping for earbuds to actually wear, and anyone hoping to use it as a normal Bluetooth transmitter for a TV or phone — those aren't in the compatibility list.
• Best for battery life → WAVEFUN Neckband. Up to 30 hours per charge beats the Relay's 25-hour rating, and the Neckband is doing the actual playing.
• Best for aptX HD music listening → WAVEFUN Neckband. It's the only one of the two that renders sound through drivers — a 10mm titanium-plated dynamic driver with a 24-bit pipeline.
• Best for airplanes and 3.5mm jacks → Avantree Relay & SoundJet. This is literally its purpose; the Neckband has no AUX input.
• Best for sharing audio with a second person → Avantree Relay & SoundJet. Two Bluetooth headphones at once, synced.
• Best for calls → WAVEFUN Neckband. It has a microphone and is designed for taking calls; the Relay has no mic and no earpiece.
• Best for running and gym wear → WAVEFUN Neckband. The flexible Nitinol neckband and magnetic earbuds are built to be worn and stored on the move. The Relay is better described as a travel accessory you keep in a bag.
• Best for anyone who already owns great headphones → Avantree Relay & SoundJet. It upgrades sources, not listeners.
• Charging convenience → Avantree Relay & SoundJet uses a modern charging standard in practice, while the WAVEFUN Neckband ships with a Micro USB cable — a small but real daily annoyance in 2026.
• Best for noise → neither offers active noise cancellation. The WAVEFUN Neckband uses sound isolation; the Relay doesn't produce sound at all, so noise handling is entirely down to the headphones you pair with it.
In my opinion, the WAVEFUN Neckband is the pick for most people searching this comparison, because it's the one that actually plays music — aptX HD support, a 10mm titanium-plated driver, a shape-memory neckband and up to 30 hours per charge cover the everyday job of listening. I'd only steer you to the Avantree Relay & SoundJet if your problem is a 3.5mm jack on a plane or an older machine and you already own Bluetooth headphones you like. They solve different problems, and buying the wrong one is an easy mistake to make. If you're comparing on cost, check the current price on Amazon for each before deciding, since the two aren't really substitutes.
The WAVEFUN Neckband supports aptX HD and standard aptX, and it's the only one of these two products that is actually a pair of earbuds. The Avantree Relay & SoundJet supports aptX Adaptive and aptX HD as well, but it's a transmitter, not a headset — it sends audio to headphones you already own, so it depends on your headphones also supporting the codec.
Yes. aptX HD is a codec that has to be supported by the source and the receiving device. A phone that only sends SBC will fall back to SBC even with WAVEFUN's aptX HD support, and the Relay can only pass aptX HD to headphones that can decode it.
No. The Relay is designed for 3.5mm AUX sources, and Avantree specifically lists phones, car stereos and hearing aids as incompatible. It's built for airplane seat-back jacks and similar analog outputs, not as a general-purpose Bluetooth adapter for your phone.
They cover different halves of a trip. The WAVEFUN Neckband is what you wear to listen to music, take calls and work out, with up to 30 hours per charge. The Avantree Relay & SoundJet is what you pack so your own Bluetooth headphones can tap into an airplane's 3.5mm entertainment jack, with up to 25 hours of playback and two-headphone support.
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