We compare products from their published specs and features; the verdicts below are our independent editorial opinions.
Updated: 2026-09-22 · 7 min read · Independent comparison
If you want a tiny, purpose-built adapter that turns any airplane seat's 3.5mm jack into a Bluetooth 5.3 stream for the headphones you already own, choose Avantree Relay & Voyager; if you need a full set of over-ear wireless headphones with adaptive noise cancellation and up to 60 hours of playback, choose Amazon Renewed Sennheiser Momentum 4.
• Avantree Relay & Voyager — biggest strength: a pocket-sized Qualcomm-based Bluetooth 5.3 transmitter with aptX Adaptive and aptX Low Latency that plugs into a 3.5mm AUX jack and streams to AirPods, Bose and other Bluetooth headphones.
• Avantree Relay & Voyager — biggest trade-off: it is an audio transmitter only — it will not work with phones, car stereos or hearing aids, and it delivers no sound on its own.
• Amazon Renewed Sennheiser Momentum 4 — biggest strength: audiophile-inspired 42mm dynamic drivers, adaptive noise cancellation, a 6 Hz–22 kHz frequency range and up to 60 hours of battery life in one folding over-ear package.
• Amazon Renewed Sennheiser Momentum 4 — biggest trade-off: it is a renewed unit sold with a 90-day limited warranty, so you accept a shorter coverage window than a new retail purchase.
• Who each pick is for: the Avantree Relay & Voyager is for travelers who already love their headphones and want in-flight audio without wires; the Momentum 4 is for someone who wants the headphone itself, with ANC and long battery life built in.
The Relay & Voyager is a travel accessory, not a listening device. Its whole job is to sit between an analog audio source — the 3.5mm AUX jack on an airplane seat, for example — and your Bluetooth headphones. Avantree builds it around a premium Qualcomm chipset with Bluetooth 5.3, and it supports aptX Adaptive and aptX Low Latency, so when your headphones also support those codecs you get high-quality audio with the kind of delay that stays in sync with what's on screen. The companion Voyager unit in this bundle carries an OLED screen and adds the latest Auracast support, which matters if you want to tap into shared broadcast audio streams in places that offer them.
Day to day, this is the thing you drop in a pocket before a flight. Plug it into the seat jack, pair once, and your AirPods, Bose or other Bluetooth headphones become your in-flight audio setup. Onboard controls let you adjust volume, pair, reconnect, clear pairing history and check battery level, and LED indicators show connection and battery status at a glance. The build is lightweight and pocket-sized, so it also makes sense for gym sessions where a machine or TV has an analog output.
Buy it if you already own headphones you like, you fly regularly, and you want to stop using the airline's disposable wired earbuds. Skip it if you're expecting a standalone pair of headphones, or if you wanted to use it with your phone, a car stereo or a hearing aid — Avantree states it isn't compatible with those, and it isn't designed to be. It also isn't a substitute for noise cancellation; it passes audio through, it doesn't cancel cabin noise.
The Momentum 4 is the opposite kind of purchase: it's the whole listening experience in one product. Sennheiser's 42mm transducer system covers a 6 Hz to 22 kHz frequency range, with aptX Adaptive on the wireless side and the Sennheiser Signature Sound tuning the brand is known for. Adaptive Noise Cancellation handles the drone of a cabin or an open-plan office, and Adjustable Transparency Mode lets you dial the outside world back in when you need to hear a gate announcement or a colleague. The Smart Control app adds an equalizer, presets and sound modes so you can shape the sound to your taste.
Comfort and stamina are the headline specs. The design is lightweight and foldable, with a padded headband and deeply cushioned over-ear pads — the kind of build that's meant to be worn for hours. Battery life runs up to 60 hours, and a 15-minute charge gets you moving again when you're short on time. For calls, four digital beamforming microphones pick up your voice and suppress wind noise, which is exactly what you want on a walk between terminals. In the box you get the headphones, a carry case, a USB-C charging cable, an audio cable with 3.5mm and 2.5mm jacks, and an airplane adapter — so wired listening on a plane is covered too, no separate transmitter required.
Two things to weigh honestly. First, this is an Amazon Renewed listing, and the warranty is described as a 90-day limited warranty — shorter than what you'd get on a new unit. Second, the software note in the specs is worth reading: firmware and software have been updated, including an ANC off switch in the Smart Control Plus app and a persistent off-switch for the touchpad. That's a meaningful usability improvement for anyone who has found touch controls finicky.
Buy it if you want one product that does noise cancellation, calls, wired and wireless playback, and marathon battery life. Skip it if you specifically want new-in-box retail packaging and a longer warranty window, or if you only need in-flight audio and already own headphones you love.
• Best for in-flight audio with your existing headphones → Avantree Relay & Voyager. Plug into the 3.5mm seat jack and stream to your own AirPods or Bose.
• Best for noise cancellation → Amazon Renewed Sennheiser Momentum 4. Adaptive ANC plus Adjustable Transparency Mode, built into the headphones.
• Best for battery life → Amazon Renewed Sennheiser Momentum 4. Up to 60 hours of playback with fast charging via a 15-minute top-up.
• Best for portability → Avantree Relay & Voyager. Lightweight and pocket-sized; the Momentum 4 folds but still takes up bag space in its carry case.
• Best for calls → Amazon Renewed Sennheiser Momentum 4. Four digital beamforming microphones with wind-noise suppression.
• Best for travel flexibility → Amazon Renewed Sennheiser Momentum 4. It ships with an airplane adapter and an audio cable, so it works wirelessly or wired.
• Best for sharing audio on a flight → Avantree Relay & Voyager. A transmitter approach lets you bring your own headphones rather than relying on airline hardware.
• Best for sound customization → Amazon Renewed Sennheiser Momentum 4. The Smart Control app's equalizer, presets and sound modes let you tune the signature.
• Best if warranty length matters most → Avantree Relay & Voyager. The Momentum 4 renewed listing carries a 90-day limited warranty.
In my opinion, these two aren't really competing for the same slot in your bag — they solve different problems, and the right answer depends on whether you already own headphones you trust. If you do, I'd buy the Avantree Relay & Voyager: it's a small, focused travel tool that gets your existing AirPods or Bose working off an airplane jack with aptX Adaptive and Bluetooth 5.3, and it costs you almost no space. If you don't own a good pair of over-ears, I'd buy the Amazon Renewed Sennheiser Momentum 4 instead, because you're getting the drivers, the ANC, the microphones, the app EQ and up to 60 hours of battery in one purchase — accepting the 90-day renewed warranty as the trade-off. Don't buy the Relay expecting headphones, and don't buy the Momentum 4 expecting it to be a cheap accessory.
FAQ
Yes — the listing describes a 90-day limited warranty. That's the main thing to accept with a renewed unit, since it's a shorter coverage window than a new retail purchase would carry.
Yes. The box includes an audio cable with 3.5mm and 2.5mm jacks plus an airplane adapter, so you can go wired if you prefer or if the seat's system requires it.
The Avantree Relay & Voyager. It's built exactly for that scenario — plug into the seat jack, pair your AirPods, and listen through your own headphones instead of the airline's.
Yes — this page doesn't publish prices, so use the "Check latest price on Amazon" button to see current pricing for whichever option fits you.
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