We compare products from their published specs and features; the verdicts below are our independent editorial opinions.
Updated: 2026-10-05 · 7 min read · Independent comparison
If you want the earbuds that carry the higher-end audio stack — aptX Lossless, Snapdragon Sound and adaptive noise cancelling — choose EarFun S1; if you need a compact transmitter that puts two Bluetooth headphones on one airplane or gym audio source at once, choose Avantree Relay & SoundJet. That is the short version, and it holds up whether you are shopping for exercise, travel, or both.
• EarFun S1 — biggest strength: Qualcomm Snapdragon Sound with aptX Lossless, plus LDAC, LE Audio and LC3 support, so it is the pick for anyone chasing the best codec support in this pairing.
• EarFun S1 — biggest trade-off: It is a single-user product. Nothing in its design lets it feed audio to a second listener at the same time.
• Avantree Relay & SoundJet — biggest strength: Dual headphone support with up to 25 hours of play time, which makes shared listening genuinely practical.
• Avantree Relay & SoundJet — biggest trade-off: It is a transmitter, not a headphone. It plugs into a 3.5mm AUX jack and is not built for phones, car stereos or hearing aids.
• Who the EarFun S1 is for: one person who wants the richest codec and noise-cancelling feature set in their own ears.
• Who the Avantree Relay & SoundJet is for: travellers and gym-goers who want two people hearing the same source, wirelessly.
The EarFun S1 is the audio-quality play here. Its headline feature is Qualcomm Snapdragon Sound with aptX Lossless, built around the Qualcomm QCC3091 SoC. That is backed by LDAC, LE Audio and LC3 codec support, so the earbuds are set up to take advantage of high-fidelity sources rather than bottleneck them. If you have ever gone looking for which earbuds support aptX HD-style codecs and been disappointed by the short list, this is the kind of spec sheet that answers the question directly.
The second pillar is noise cancelling. Adaptive Hybrid ANC is rated up to 50dB, and it uses QuietSmart 3.0 to detect your ear canal shape and adjust performance accordingly. That is a meaningful design choice for anyone who wears earbuds in noisy environments — a gym floor, a busy street, a train carriage — because the seal and the cancellation are being tuned to the individual rather than set once at the factory.
Calls get their own attention too. Six microphones, AI algorithms and Qualcomm cVc 8.0 combine for environmental noise cancellation on voice, which matters if you take meetings or calls while out and about rather than sitting in a quiet room.
Who should buy it: one listener who wants the strongest codec stack and the most capable ANC in this comparison, and who mostly listens alone. Who should skip it: anyone whose main problem is getting two people onto the same audio source. The S1 has no dual-headphone mode — that is simply not what it is designed to do.
The Avantree Relay & SoundJet solves a completely different problem, and it solves it well. It is a premium airplane Bluetooth adapter built on a Qualcomm chipset with aptX Adaptive and HD audio, running Bluetooth 5.3 for stability. Plug it into a 3.5mm AUX jack and it streams that audio to your Bluetooth headphones.
The feature that defines it is dual headphone support. Two Bluetooth headphones can connect at once with synced playback, which is the difference between one person watching a film and two people watching it together on a long flight. Compatibility covers AirPods, Bose and Bluetooth headphones generally — but note the explicit limits: it is not compatible with phones, car stereos or hearing aids. That is a travel and shared-listening device, not a general-purpose dongle.
Battery life is rated at up to 25 hours of continuous playback, and the controls are deliberately simple: LED indicators for connection status and onboard buttons for pairing and volume. The design is lightweight and pocket-sized, and Avantree positions it as a travel essential for flights and gym sessions alike.
Who should buy it: travellers who want to use their own Bluetooth headphones with in-flight entertainment, gym-goers sharing one audio source, and anyone who regularly listens alongside a second person. Who should skip it: if you want earbuds in your ears, this is the wrong category of product entirely. It has no drivers, no ANC and no codec support of its own to speak of beyond what it transmits.
Side-by-Side: Which Should You Choose?
• Best for noise cancelling → EarFun S1. Adaptive Hybrid ANC up to 50dB with QuietSmart 3.0, versus none on the Relay.
• Best for clear calls → EarFun S1. Six mics, AI algorithms and Qualcomm cVc 8.0 are built specifically for voice clarity in noisy places.
• Best for sharing audio with a second person → Avantree Relay & SoundJet. Dual headphone support with synced playback is a feature the S1 does not have.
• Best for long sessions away from a charger → Avantree Relay & SoundJet. Up to 25 hours of continuous playback is stated plainly, and it is the only battery figure given in this pairing.
• Best for travel and in-flight entertainment → Avantree Relay & SoundJet. The 3.5mm AUX design is aimed squarely at airplane seat jacks.
• Best for exercise as a solo listener → EarFun S1. ANC plus an adaptive fit makes it the more useful pick when you are moving through a loud environment on your own.
• Best if you already own good Bluetooth headphones → Avantree Relay & SoundJet. It upgrades the source, not the ears.
In my opinion, the EarFun S1 is the one I would buy, and it comes down to how much capability sits inside a single product. aptX Lossless with Snapdragon Sound, LDAC and LE Audio support, up to 50dB of adaptive ANC, and a six-mic call setup is a genuinely deep feature set for one listener. For exercise in particular, that combination of adaptive noise cancelling and a high-fidelity codec stack is the more rewarding everyday choice. I would pick the Avantree Relay & SoundJet only if my real problem were sharing one audio source with a second pair of headphones — and for that specific job, it is the better tool. Before deciding, check the current price on Amazon, since the two sit in different product categories and value depends on which problem you actually have.
FAQ
which earbuds support aptx hd
best low latency on ear headphones for exercise
Low latency for exercise comes down to the codec and chipset. The EarFun S1 runs the Qualcomm QCC3091 SoC with Snapdragon Sound, aptX Lossless, LE Audio and LC3 — LE Audio and LC3 in particular are designed with low-latency listening in mind. The Avantree Relay & SoundJet also uses aptX Adaptive, but it transmits to headphones you already own rather than being worn itself.
best sleep headphones for exercise
Neither product is designed as a sleep headphone, and I would not position them that way. The EarFun S1 is an in-ear design with adaptive ANC up to 50dB, which suits noisy environments and movement. The Avantree Relay & SoundJet is a small transmitter that plugs into a 3.5mm AUX jack. If sleep comfort is your priority, look at products built for that purpose instead.
best lightweight over ear headphones for exercise
Neither option here is an over-ear headphone. The EarFun S1 is an in-ear design, and the Avantree Relay & SoundJet is a pocket-sized adapter rather than a headphone at all. For exercise, the practical question is whether you want earbuds with ANC (the S1) or a way to share one audio source with two Bluetooth headphones (the Relay).
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