How We Research
We compare products from their published specs and features; the verdicts below are our independent editorial opinions.
If you want the cleanest path to true aptX Adaptive headphones for college students — a single pocketable box that turns wired cans into a lossless wireless rig and doubles as a USB DAC — choose Questyle M18i; if you need a complete wireless travel kit with active noise cancelling earbuds included, choose Avantree Relay.
• Questyle M18i — biggest strength: ESS ES9219Q DAC plus two patented quad-core Current Mode Amplifier SiP modules, with aptX Adaptive, aptX HD, LDAC, LE Audio and 3.5mm unbalanced / 4.4mm balanced outputs in one aluminum body.
• Questyle M18i — biggest trade-off: It's a source, not a listening device. No noise cancelling, no earbuds in the box, and it expects you to bring your own headphones.
• Avantree Relay — biggest strength: A two-piece bundle — Relay transmitter plus Infinity NC earbuds — built around a six-microphone ANC system and aptX Adaptive on both ends.
• Avantree Relay — biggest trade-off: Relay is a transmitter, not a DAC. It only accepts 3.5mm analog input and won't work with TVs, phones, assistive listening devices, musical instruments or real-time monitoring.
• Pick Questyle M18i if you already own wired headphones or IEMs and want to upgrade them, or you listen from a phone, PC or laptop and care about codec flexibility.
• Pick Avantree Relay if you want everything in one box for flights, offices and noisy dorms, and you'd rather not buy headphones separately.
The M18i is a headphone amplifier, Bluetooth 5.4 receiver and portable USB DAC in one small aluminum chassis. At its core is the ESS flagship ES9219Q DAC chip, which Questyle co-developed with ESS around its own TTA DAC framework. That matters because it's doing the digital-to-analog conversion itself rather than passing a signal along. Two patented quad-core Current Mode Amplifier SiP modules supply the drive, and Questyle rates distortion at 0.0002%.
The connectivity is the headline for anyone chasing aptX Adaptive headphones. The M18i runs Qualcomm Snapdragon Sound with Bluetooth 5.4 and covers AAC, SBC, aptX, aptX HD, aptX Adaptive, LE Audio and LDAC at up to 24-bit/96kHz. It's certified for both Qualcomm Snapdragon Sound and LDAC. Practically, that means it can talk to almost any wireless headphone you already own — or you can skip Bluetooth entirely, plug in via USB and use it as a DAC. It switches seamlessly between the two modes.
Buy it if you already own good wired headphones or IEMs and want a compact way to drive them wirelessly or from a laptop, and you want manual gain control, a 4.4mm balanced output and 60 volume steps to fine-tune the match. Skip it if you want noise cancelling, if you want earbuds included, or if you mostly listen to a TV or a musical instrument — this isn't that kind of device. Its 12-month warranty and 0.14 kg weight make it a genuinely pocketable travel companion, and the 2-hour charge time is the only battery figure the spec sheet gives, so plan around a top-up rather than a marathon.
For a college student, this is the "make my existing headphones better" pick. It lives in a backpack, works with a phone on the bus and a laptop in the library, and covers 20 Hz to 20,000 Hz with 300-ohm impedance support for harder-to-drive cans.
Avantree's Relay is a bundle, and that's the point. You get the Relay Bluetooth transmitter and a pair of Avantalk Infinity NC active noise cancelling earbuds, packaged as a complete wireless travel kit. The transmitter plugs into a 3.5mm audio jack — most obviously an airplane seat's entertainment port — and beams the audio wirelessly to the earbuds. Movies, music and even announcements come through your own earbuds instead of a nasty pair of airline cans.
The Infinity NC earbuds carry the noise-cancelling load with a six-microphone ANC system aimed at airplanes, offices and other busy spaces. Both halves of the bundle support aptX Adaptive, which is what keeps audio and picture in sync when the two are used together — the low-latency part of the codec doing real work on a flight. The earbuds also handle LE Audio and Auracast, so they'll pair with compatible phones, PCs, TVs and public Auracast broadcasts, and the Relay transmitter itself will work with other Bluetooth headphones and earbuds you already own. Relay supports two pairs of Bluetooth headphones, has onboard volume controls and is described as offering up to 25 hours of battery life.
Buy it if you fly, commute through loud spaces, or study in noisy common areas and want one purchase that covers both the transmitter and the earbuds. Skip it if you want to drive high-impedance wired headphones, if you need a DAC or a wired output, or if you want to use it with a TV, phone, assistive listening device, musical instrument or real-time monitoring — Avantree states Relay does not support those.
• Best for aptX Adaptive codec flexibility → Questyle M18i. It covers AAC, SBC, aptX, aptX HD, aptX Adaptive, LE Audio and LDAC, plus USB DAC mode.
• Best for noise cancelling → Avantree Relay. The six-microphone ANC system in the Infinity NC earbuds is the whole reason the bundle exists.
• Best for driving serious wired headphones → Questyle M18i. 4.4mm balanced and 3.5mm unbalanced outputs, manual gain, 300-ohm impedance support.
• Best for a single-box travel setup → Avantree Relay. Transmitter plus earbuds, no separate headphone purchase needed.
• Best for flying → Avantree Relay. Plug into the seat's 3.5mm jack, listen through your own ANC earbuds.
• Best long battery life headband headphones for college students → neither, strictly speaking. Relay's 25-hour figure belongs to the transmitter and the bundle uses earbuds, not headband headphones — if headband headphones are non-negotiable, the M18i is the piece that will actually drive them.
• Best for wired listening from a laptop → Questyle M18i. USB DAC mode with seamless switching.
• Best for Auracast and public broadcasts → Avantree Relay. The Infinity NC earbuds support Auracast; the M18i does not list it.
For most college students, I'd buy the Questyle M18i. In my opinion it's the more flexible long-term purchase: it makes whatever headphones you already own better, it works as both a Bluetooth receiver and a USB DAC, and its codec list — aptX Adaptive, aptX HD, LDAC, LE Audio — is about as future-proof as a small box gets. If you own nothing decent yet and you fly or study in loud places, the Avantree Relay bundle is the smarter single purchase, because it hands you ANC earbuds and a transmitter together. Either way, check the current price on Amazon before you commit.
FAQ
Yes. The M18i is a DAC and amplifier, not a listening device — there are no earbuds or headphones included. You supply your own wired headphones or IEMs and connect them via the 3.5mm or 4.4mm output.
No. Avantree states Relay is not compatible with TVs, phones, assistive listening devices, musical instruments or real-time monitoring. It's built for 3.5mm analog audio sources, and the included Infinity NC earbuds are what you'd pair with compatible phones, PCs and TVs.
That depends on whether you already own headphones. If you do, the M18i upgrades what you have and avoids a second purchase. If you don't, the Relay bundle covers both the transmitter and the ANC earbuds in one go. Compare the current prices on Amazon for both before deciding.
As an Amazon Associate I earn from qualifying purchases.
We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon and affiliated sites.
When you buy through links on this page, we may earn a commission from qualifying purchases at no extra cost to you.
Amazon and the Amazon logo are trademarks of Amazon or its affiliates. This site is an independent third-party review and is not affiliated with, endorsed by, or sponsored by Amazon or the product brands mentioned.
See also: Candeo Headset V4.2 vs Yealink BH71: Business Bluetooth, Razer Kraken Kitty V2 vs muso wood Walnut Headphone Stand, iJoy Over-Ear vs Rebocico Over Ear Headphones, TJZXGUI Kids Headphones Bulk vs KVIDIO Headphones