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We compare products from their published specs and features; the verdicts below are our independent editorial opinions.
Updated: 2026-10-06 · 6 min read · Independent comparison
• 1Mii B03Pro — biggest strength: A true transmit/receive audio hub with a built-in SABRE DAC, Class 1 Bluetooth range up to 265 ft line-of-sight, and aptX HD/Adaptive/Low Latency support for dual headphones or speakers.
• 1Mii B03Pro — biggest trade-off: It's a corded, desk-bound box (3.8" x 2.9" x 0.9", 106 g) that needs power and an audio cable, so it stays put rather than traveling with you.
• Avantree Relay & Voyager — biggest strength: A battery-powered, pocket-sized adapter with an OLED display and LED indicators that streams audio from a 3.5mm AUX jack straight to your Bluetooth headphones.
• Avantree Relay & Voyager — biggest trade-off: It's built for headphones only — Avantree states it's not compatible with phones, car stereos, or hearing aids, and its input is limited to 3.5mm AUX.
• Who each is for: The 1Mii B03Pro is for the home office or living-room setup where you want one box to handle TV, stereo, and dual-headphone audio. The Avantree Relay & Voyager is for the traveler or gym-goer who wants to keep using their own Bluetooth headphones on a wired source.
The B03Pro is really a small audio computer disguised as a dongle. Inside, 1Mii pairs a SABRE DAC with a Qualcomm chip and advertises a signal-to-noise ratio of 121dB — a number you normally see quoted for dedicated Hi-Fi gear, not TV adapters. In plain terms, that's the spec that tells you this box is built to keep quiet passages quiet and loud passages clean, which is exactly what matters when you're on back-to-back video calls or listening to music all afternoon while you work.
Who should buy it: anyone building a best wireless headset for work from home setup who wants one powered box to feed a TV, a stereo, or a pair of headphones without swapping dongles. Who should skip it: travelers. It's ABS plastic, corded, and needs a USB power adapter — this is furniture, not a carry-on item. Also note 1Mii's caveats: aptX HD/Adaptive/LL only kick in if your headphones support the matching codec, you can't run TX and RX at the same time, and pairing two aptX LL headphones drops the codec to aptX for stability.
Avantree Relay & Voyager: Who It's For
The Relay & Voyager does one job and does it in a very specific place: the airplane seat. You plug it into a 3.5mm AUX jack — the kind on in-flight entertainment systems — and it streams that audio to your Bluetooth headphones. Avantree built it on a Qualcomm chipset with aptX Adaptive and aptX HD plus Bluetooth 5.3, so when your headphones support those codecs you're getting high-quality, low-latency audio rather than the mushy default stream.
The controls are the standout. There's an OLED display plus LED indicators, and built-in buttons let you adjust volume, pair, reconnect, clear pairing history, and check battery level — the kind of feedback that matters when you're mid-flight and can't troubleshoot. It's battery powered, lightweight, and pocket-sized, and Avantree pitches it for flights and gym sessions. It's compatible with AirPods, Bose, and Bluetooth headphones generally.
Two limits are worth repeating because Avantree states them plainly: it's not compatible with phones, car stereos, or hearing aids, and its only audio input is 3.5mm AUX. So it won't replace a TV transmitter or a home-stereo receiver. Who should buy it: frequent flyers and gym users who already own good Bluetooth headphones and just need to bridge them to a wired jack. Who should skip it: anyone who wants a permanent home-office audio hub — that's not what this is.
• Best for a work-from-home audio hub → 1Mii B03Pro. Optical, RCA, and AUX in/out plus Transmit/Receive/Bypass modes cover a desk, a TV, and a stereo.
• Best for travel and flights → Avantree Relay & Voyager. Battery powered, pocket-sized, and made for 3.5mm AUX sources.
• Best for aptX HD/Adaptive flexibility at home → 1Mii B03Pro. It lists aptX HD, aptX Adaptive, and aptX Low Latency with a Qualcomm chip and SABRE DAC.
• Best for portable aptX Adaptive → Avantree Relay & Voyager. Qualcomm chipset with aptX Adaptive and aptX Low Latency in a carry-friendly body.
• Best for dual-device listening → 1Mii B03Pro. Dual-link connects two Bluetooth headphones or two speakers at once.
• Best for on-device status info → Avantree Relay & Voyager. OLED display, LED indicators, and buttons for volume, pairing, and battery level.
• Best for range → 1Mii B03Pro. Class 1 Bluetooth with dual antennas, up to 265 ft line-of-sight / 80–110 ft indoors.
• Best for people who want zero setup fuss → Avantree Relay & Voyager. Plug into AUX, pair your headphones, done.
For a work from home setup, I'd buy the 1Mii B03Pro. In my opinion, the combination of a SABRE DAC, aptX HD/Adaptive/Low Latency, dual-link pairing, and Optical/RCA/AUX flexibility makes it the more useful box to live with day after day — it can feed headphones, a stereo, and a TV without you touching a cable. The Avantree Relay & Voyager is genuinely good at what it does, but its world is the airplane seat and the gym, not the desk. If your priority is travel, flip that recommendation. If your priority is a permanent bluetooth earbuds for work from home rig, the B03Pro wins. Worth checking the current price on Amazon for both before you commit.
FAQ
The 1Mii B03Pro, in my opinion. It has Optical, RCA, and 3.5mm AUX in/out, Transmit/Receive/Bypass modes, dual-link pairing, and it runs on corded power. The Avantree Relay is battery powered with only a 3.5mm AUX input, so it's better suited to travel than a desk.
No — Avantree states it isn't compatible with phones, car stereos, or hearing aids, and its only input is 3.5mm AUX. It's designed to pull audio from a wired AUX source like an in-flight system into Bluetooth headphones, not to act as a home TV transmitter.
The 1Mii B03Pro uses Class 1 Bluetooth with dual antennas, rated up to 265 ft line-of-sight outdoors and about 80–110 ft indoors, though walls and Wi-Fi reduce that. Avantree doesn't publish a range figure for the Relay & Voyager — it's a short-reach, in-seat adapter rather than a long-range transmitter.
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