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We compare products from their published specs and features; the verdicts below are our independent editorial opinions.
Updated: 2026-09-30 · 7 min read · Independent comparison
• Motorola SF600, biggest strength: a genuine wireless in-ear sports headphone with aptX HD-class Bluetooth audio, a hook-style fit and moisture-resistant materials — it does the whole job on its own.
• Motorola SF600, biggest trade-off: no active noise cancellation and no wired fallback — battery and Bluetooth are the only way to listen, so charging discipline matters.
• Avantree Relay & SoundJet, biggest strength: pairs two Bluetooth headphones simultaneously on a flight with up to 25 hours of playtime and Qualcomm aptX Adaptive — a shared-listening travel tool.
• Avantree Relay & SoundJet, biggest trade-off: it is a transmitter only, and Avantree explicitly says it is not for TVs, phones, hearing aids or musical instruments — it is not a headphone and not a general-purpose adapter.
• Who each pick is for: the SF600 is for the runner, cyclist or gym-goer who wants one pair of wireless earbuds; the Relay & SoundJet is for the frequent flyer who already owns headphones and wants to use them on the plane.
The SF600 is a wireless in-ear sports headphone built around movement. The earpiece shape is a hook, which means the housing wraps over the top of your ear rather than relying purely on the tip pressing into your canal — that is the classic design choice for running and lifting, where a straight in-ear can work loose mid-set. The enclosure uses Kevlar, with silicone and a hydrophobic mesh handling moisture, so sweat and drizzle are part of the design brief rather than an accident waiting to happen.
On the audio side, Motorola builds in APT-X codec support and describes the tuning as HD audio aimed at matching wired-headset performance. That is the headline for anyone searching for aptX HD earbuds: a Bluetooth in-ear that is explicitly codec-forward rather than just "wireless." A dynamic driver handles the output. Fit is addressed with ear cushions in five sizes, which is unusually generous and matters a lot for a hook design — a secure seal is what keeps both the bass and the grip.
Control is handled by a remote with media controls, and the included kit covers ear cushions and the earphone itself. Item weight is listed at 3.2 ounces, so this is a lightweight package you can wear through a long session.
Who should buy it: runners, gym regulars and anyone who wants a self-contained wireless earbud with sweat-resistant materials and aptX support, and who values a hook fit over a fully sealed in-ear. Who should skip it: if you need active noise cancellation, the SF600 has none — noise control is listed as "None," so it will not silence a noisy gym or a plane cabin. Skip it too if you want a wired option when the battery runs out, because connectivity is Bluetooth only. And if you are looking for an adapter to feed audio into headphones you already own, this is the wrong category of product entirely.
The Avantree Relay & SoundJet R1 is a different animal: a premium airplane Bluetooth adapter built on an advanced Qualcomm chipset. Its party trick is stated plainly — pair two Bluetooth headphones or AirPods at the same time and watch in-flight entertainment together. For couples or travel partners sharing a screen on a long-haul flight, that is the entire value proposition in one feature.
Under the hood it runs Qualcomm aptX Adaptive, which Avantree positions as balanced sound with dependable wireless performance through a flight. Playtime is up to 25 hours on a single charge, which is aimed squarely at international routes and frequent travelers — enough for a very long itinerary without hunting for a USB port in the terminal.
But read the fine print before you buy. Avantree is unusually direct: this is not for TVs, phones, hearing aids or musical instruments, and as a Bluetooth transmitter only, it does not pair with phones or tablets. It is not an earbud, it does not make sound on its own, and it will not become your everyday audio device.
Who should buy it: frequent flyers who already own good Bluetooth headphones or AirPods and want to use them with the seatback system, especially two people who want to listen to the same thing. Who should skip it: anyone hoping for a universal Bluetooth transmitter for a home TV, a phone, a hearing aid or an instrument — Avantree rules all of those out. Skip it as well if you travel solo and just want one pair of headphones, since a single-user setup does not need the two-headphone pairing.
• Best for working out → Motorola SF600. Hook fit, Kevlar enclosure, hydrophobic mesh and silicone moisture sealing are all pointed at sweat and movement.
• Best for shared in-flight listening → Avantree Relay & SoundJet. Two headphones at once is the feature that decides this category.
• Best for battery life on a trip → Avantree Relay & SoundJet. Up to 25 hours of playtime is stated for the adapter, aimed at long international flights.
• Best for a self-contained wireless earbud → Motorola SF600. It is the only one of the two that actually makes sound in your ears.
• Best for codec-focused listeners on the move → Motorola SF600. APT-X support plus a dynamic driver, in a wireless in-ear.
• Best for travelers who already own headphones → Avantree Relay & SoundJet. It upgrades gear you already like instead of replacing it.
• Best if you need noise cancellation → neither. The SF600 lists noise control as none, and the Avantree is a transmitter, not a headphone.
• Best if you want a wired fallback → neither. The SF600 is Bluetooth-only, and the Avantree is Bluetooth-only by definition.
In my opinion these two should not really be competing for the same slot in your bag — they answer different questions. If I had to pick one for the average reader landing on this page, I would buy the Motorola SF600, because it is the complete product: a wireless in-ear with aptX-class audio, a secure hook fit and sweat-resistant materials that works the moment you unbox it. I would only steer you to the Avantree Relay & SoundJet if your actual problem is a plane seatback and two people who want to hear it on their own headphones. Buy for the job you have, not for the codec label they share. Whichever way you go, check the current price on Amazon before committing.
which earbuds support aptx hd
The Motorola SF600 is the earbud here with aptX support — Motorola lists APT-X codec technology among its HD audio capabilities, paired with a dynamic driver in a wireless in-ear design. The Avantree Relay & SoundJet is not an earbud; it is a Bluetooth transmitter using Qualcomm aptX Adaptive to send audio to headphones you already own. So if the question is which earbuds to put in your ears, the answer is the SF600.
Do I need a transmitter if I already have aptX headphones?
No. The SF600 lists noise control as none, so it does not actively cancel cabin noise. Its design strengths are elsewhere: a hook-style in-ear fit, Kevlar in the enclosure, hydrophobic mesh and silicone for moisture protection, and five sizes of ear cushions for a secure seal. A good seal will naturally dull some ambient sound, but that is passive isolation from fit, not noise cancellation.
The Motorola SF600, clearly. It is a wireless in-ear sports headphone with a hook earpiece shape, moisture-resistant materials and multiple ear cushion sizes — all of which point at sweaty, high-movement use. The Avantree Relay & SoundJet is a travel adapter for airplanes and is explicitly not intended for phones or general home use. For training, the SF600 is the only sensible choice of the two.
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