We compare products from their published specs and features; the verdicts below are our independent editorial opinions.
Updated: 2026-09-27 · 6 min read · Independent comparison
If you want a pocket-sized USB-C DAC-amp that can drive both sensitive IEMs and hard-to-power full-size headphones while letting you save custom EQ profiles to the device, choose CrinEar Protocol Max; if you need wireless over-ear headphones with active noise cancelling, a 60-hour battery and the freedom to move around untethered, choose Monster Persona 6th.
• CrinEar Protocol Max — biggest strength: dual Cirrus Logic CS43198 DACs plus dual SG Micro SGM8262-2 op-amps pushing up to 600mW through a balanced 4.4mm output, with a 10-band parametric EQ you can save straight onto the device from a PC browser.
• CrinEar Protocol Max — biggest trade-off: it's a wired USB-C source device with no noise cancelling, no battery-free wireless convenience, and it depends on whatever headphones or IEMs you already own.
• Monster Persona 6th — biggest strength: all-in-one wireless listening with active noise cancelling, transparency and balanced modes, Bluetooth 6.0 and up to 60 hours of playback per charge.
• Monster Persona 6th — biggest trade-off: it ships a single 40mm dynamic driver with no wired jack, so its sound is fixed by the headphone itself and can't be re-tuned the way a dedicated DAC-amp lets you.
• Who each is for: CrinEar Protocol Max for listeners who already own good wired IEMs or headphones and want to upgrade the source; Monster Persona 6th for commuters, travelers and desk workers who want one wireless pair for everything.
The Protocol Max is not a headphone. It's a thumbdrive-sized USB-C DAC-amplifier, and that distinction matters when you're comparing it to a wireless over-ear. What CrinEar has built here is a source device: dual Cirrus Logic CS43198 DAC chips for the digital-to-analog conversion, dual SG Micro SGM8262-2 op-amps for the amplification stage, and up to 600mW of clean output through the balanced 4.4mm connection. That's enough headroom to drive sensitive IEMs without hiss and demanding full-size headphones without running out of steam.
The feature that stands out to me is the browser-based Hangout.Audio Graph Tool. It gives you a 10-band parametric EQ, and you can save profiles directly to the device from a PC browser — no companion app, no account, no phone in the chain. For anyone who likes to nudge a peaky treble region down or add a shelf to a lean-sounding IEM, having that EQ live on the hardware itself is genuinely convenient. There are also two power modes: Eco for longer runtime and Boost for maximum output, plus both 4.4mm balanced and 3.5mm single-ended outputs with low output impedance (0.2 ohm listed, under 0.3 ohm single-ended) so it plays nicely with a wide range of gear.
Who should buy it: people who already own wired IEMs or headphones and want to hear them at their best from a laptop or phone, and tinkerers who want on-device PEQ. Who should skip it: anyone who wants wireless freedom, active noise cancelling, or an all-in-one solution out of the box. The enclosure is aluminum in black, it weighs 110g, and it ships with a USB C-to-C cable, a USB C-to-A adapter and a manual. Check the current price on Amazon before deciding — value here depends entirely on what you're plugging into it.
The Persona 6th is the opposite philosophy: everything in one pair of over-ear headphones, no wires required. Monster leans on its Pure Monster Sound tuning for a bass-forward, "clear highs, deep bass" presentation, and the spec sheet backs up the everyday-usability angle with Bluetooth 6.0, dual pairing for switching between phone and laptop, and hands-free calling.
The headline number is battery: up to 60 hours of playback, with a 10-minute charge giving roughly 5 hours. That's the kind of endurance that makes charging anxiety disappear on a long trip or a heavy workweek. Noise control is active noise cancelling, and Monster quotes blocking up to 25dB, with transparency mode for staying aware on commutes and a standard balanced mode for general listening. The build is plastic in white, with plush slow-rebound memory foam earcups, a lightweight adjustable headband and a folding design for packing.
Who should buy it: commuters, flyers and office workers who want one wireless pair that handles noise, calls and long days without a charger. Who should skip it: anyone who wants a wired connection — there's no headphone jack at all, the connection is Bluetooth only (plus Type-C charging) — or listeners who want to reshape the tuning, since the sound is set by the 40mm dynamic driver and the three modes give you broad strokes rather than a proper parametric EQ.
• Best for driving demanding wired headphones → CrinEar Protocol Max. 600mW over balanced 4.4mm is the reason it exists.
• Best for wireless freedom and travel → Monster Persona 6th. Bluetooth 6.0, no cable, folding design.
• Best for battery life → Monster Persona 6th. Up to 60 hours per charge, versus a portable DAC-amp that needs its own charging.
• Best for noise cancelling → Monster Persona 6th. Active noise cancelling with a transparency mode; the Protocol Max has no noise control at all.
• Best for customizing your sound → CrinEar Protocol Max. The 10-band PEQ saved to the device is something the Persona 6th simply doesn't offer.
• Best for calls → Monster Persona 6th. Hands-free calling and dual pairing; the Protocol Max is a listening device.
• Best if you already own good IEMs → CrinEar Protocol Max. It upgrades what you have instead of replacing it.
• Best if you own nothing and want one box → Monster Persona 6th. Headphones, cable and case-level portability in a single purchase.
If I had to pick one, I'd buy the CrinEar Protocol Max — but only because of who I am as a listener. I already own wired IEMs and full-size headphones, and a DAC-amp with dual CS43198 chips, 600mW of balanced output and on-device parametric EQ is the piece that makes all of them better. In my opinion, the Monster Persona 6th is the smarter buy for most people who just want one wireless pair for commuting and work, thanks to the 60-hour battery and ANC. They solve different problems; pick the one that matches yours.
No. It's a portable USB-C DAC-amplifier. You plug your own wired IEMs or headphones into its 4.4mm balanced or 3.5mm single-ended output.
No. The connection is Bluetooth only, with a Type-C port for charging. There is no 3.5mm jack, so wired listening isn't an option.
The Monster Persona 6th. It has active noise cancelling (Monster cites up to 25dB) plus a transparency mode. The CrinEar Protocol Max lists no noise control of any kind.
Yes, via USB-C. It ships with a USB C-to-C cable and a USB C-to-A adapter, so it works with phones, laptops and desktop ports alike. Just check the current price on Amazon, since it's a very different kind of purchase than a pair of headphones.
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