If you want wireless in-ear headphones for exercise and everyday listening, choose ICESOMNUS Sabbat E16; if you need to connect two Bluetooth headphones to an airplane’s audio system, choose Avantree Relay & SoundJet. For exercise, the E16 is the relevant choice: it is a pair of in-ear earbuds, while the Avantree bundle is an airplane Bluetooth transmitter and headphones—not a competing pair of exercise earbuds.
ICESOMNUS Sabbat E16 vs Avantree Relay & SoundJet at a Glance
• Avantree Relay & SoundJet strength: The Relay transmitter can send audio from an airplane’s 3.5 mm AUX output to two Bluetooth headphones at once. Trade-off: It is not a standalone pair of exercise earbuds and is explicitly not for TVs, phones, tablets, hearing aids, or musical instruments.
• Choose the E16 if you want in-ear headphones for exercise, music, movies, and everyday Bluetooth listening, with an included charging case.
• Choose the Relay & SoundJet if your priority is sharing airplane entertainment with another person and you need a transmitter with two-headphone support.
The Sabbat E16 is a conventional pair of wireless in-ear earbuds. Its coaxial design combines a dynamic driver for bass with a balanced-armature driver intended to bring clarity to vocals and finer musical details. That arrangement makes the E16 the more direct fit for someone who wants one pair for music, movies, and general listening rather than a separate airplane adapter.
Its Bluetooth 5.2 connection supports aptX, AAC, and SBC. The stated frequency range is 20 Hz to 20 kHz, and the listed latency is 40 ms. Those specifications describe a broad playback range and a low-latency mode; they do not guarantee that every phone or app will use a particular codec or deliver identical results. For exercise, the practical appeal is simpler: these are earbuds with no cable running between the listener and a phone, and the charging case gives them a portable place to recharge between sessions.
The earbuds are rated for more than six hours of playback per charge, with up to 30 hours stated when the case is included. The case supports USB-C and Qi wireless charging, and the listed earbud charging time is about 60 minutes. An ergonomic in-ear shape and automatic pairing when the case is opened round out the everyday-use features. The available details do not specify a water-resistance rating or an exercise-specific fit test, so I would not assume sweat protection or a guaranteed secure fit during vigorous movement.
Who should skip it: Skip the E16 if your main need is to transmit airplane-seat audio to two Bluetooth headphones; that is not its stated role.
The Avantree Relay & SoundJet is a travel bundle built around the Relay airplane Bluetooth transmitter and SoundJet R1 headphones. The transmitter takes audio through a 3.5 mm AUX input, then sends it over Bluetooth. Its standout use is pairing two Bluetooth headphones at once, which can let travel partners listen to the same in-flight entertainment without sharing a wired connection.
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We compare products from their published specs and features; the verdicts below are our independent editorial opinions.
Updated: 2026-10-17 · 7 min read · Independent comparison
The bundle supports Qualcomm aptX Adaptive, and the stated battery life is up to 25 hours. Those details make it relevant to a long flight where a traveler wants wireless listening and enough stated runtime for extended use. The 25-hour figure applies to the bundle’s advertised playback time; it is not a claim about the E16 or a general measure of how long every setup will last in every situation.
Who should skip it: Skip the bundle if you need earbuds to connect directly to a phone for exercise or everyday listening; the Relay is not designed for that job.
Side-by-Side: Which Should You Choose?
• Best fit for exercise → ICESOMNUS Sabbat E16. It is the only product here described as in-ear earbuds for ordinary wireless listening. The Avantree bundle is centered on an airplane transmitter.
• Best for sharing airplane audio with two listeners → Avantree Relay & SoundJet. Its defining function is sending audio from a 3.5 mm AUX source to two Bluetooth headphones at the same time.
• Best for a long stated listening window on a travel setup → Avantree Relay & SoundJet. Its listed playtime is up to 25 hours. The E16 is listed for more than six hours per earbud charge and up to 30 hours with its charging case, so the relevant figure depends on whether you mean a transmitter-and-headphone travel session or earbuds plus case.
• Best for a choice of charging methods → ICESOMNUS Sabbat E16. Its case supports USB-C and Qi wireless charging.
• Best when an airplane seat’s 3.5 mm AUX output is the source → Avantree Relay & SoundJet. AUX is the transmitter’s stated audio input.
• Best for an in-ear design with a dual-driver arrangement → ICESOMNUS Sabbat E16. Its dynamic and balanced-armature drivers are presented as working together for bass, vocals, and detail.
• Best active noise cancelling earbuds for exercise → Neither is a clear match based on the available details. The E16 lists noise-control features, including active noise cancellation and Qualcomm CVC8.1 noise reduction for calls, but the information does not establish exercise-focused noise-cancelling performance. The Avantree product is not an exercise-earbud set.
I would choose the ICESOMNUS Sabbat E16 for exercise and everyday listening because it is the pair of wireless in-ear earbuds here, with a dual-driver design, several supported codecs, and a charging case. I would choose the Avantree Relay & SoundJet only when the specific job is sharing airplane audio between two Bluetooth headphones. For someone searching for the best headset for exercise, I would start with the E16, while keeping in mind that no sweat-resistance rating or secure-fit guarantee is provided.
Buying Considerations
Also consider whether you need one listener or two. The E16 is the straightforward option for a person who wants their own earbuds for music, movies, and exercise. The Avantree bundle is more specialized: it supports two Bluetooth headphones from the transmitter, but it is not listed as a phone or tablet pairing device.
Battery claims describe different setups, so they are not a simple head-to-head measure. The E16 is specified for more than six hours per charge and up to 30 hours with its case; the Avantree bundle lists up to 25 hours. If charging convenience matters, only the E16 sheet specifies USB-C and Qi wireless charging for the case. If exercise is the priority, remember that the available E16 details do not state a water-resistance rating. Check the current price on Amazon if price is part of your decision; the product details here do not establish which option costs less.
They are wireless in-ear earbuds, so their form fits the basic need for untethered listening during exercise. However, the available details do not state a water-resistance rating or guarantee a secure fit during vigorous movement.
The Relay is described as an airplane Bluetooth transmitter, with a 3.5 mm AUX audio input. It is specifically not designed to pair with phones or tablets, so it is not the choice for direct phone listening.
The Avantree Relay & SoundJet is the relevant option if two people want to listen through Bluetooth headphones from an airplane audio source. The E16 is a pair of earbuds, but its listed features do not include transmitting airplane-seat audio to a second pair.
The E16 product information lists active noise cancellation and Qualcomm CVC8.1 intelligent noise reduction for calls. Those details do not establish a specific level of noise reduction for exercise or a claim that it blocks surrounding sound in every setting.
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