We compare products from their published specs and features; the verdicts below are our independent editorial opinions.
Updated: 2026-10-03 · 7 min read · Independent comparison
If you want a tunable, semi-open in-ear monitor you can shape to your own taste, choose FiiO FH5s; if you need a closed-back, over-ear studio reference headphone built to isolate and last, choose beyerdynamic Box.
• FiiO FH5s — biggest strength: a hybrid driver setup (12mm beryllium-plated dynamic low driver, 6mm beryllium-plated dynamic mid driver, Knowles TWFK-30017 balanced armature for treble) plus 3 tuning switches giving 8 possible sound signatures.
• FiiO FH5s — biggest trade-off: it's an in-ear design with a semi-open rear cavity, so it doesn't isolate the way a closed-back headphone does, and it relies on the ear tip seal for its bass.
• beyerdynamic Box — biggest strength: a closed-back over-ear design with 250 ohm drivers and a wide 5–35,000 Hz range, made for accurate, isolated monitoring and known for enduring build quality.
• beyerdynamic Box — biggest trade-off: 250 ohms needs a proper amplifier or a strong source to sound its best, and a closed-back over-ear is bulkier and less portable than an IEM.
• Pick FiiO FH5s if you want a portable, customizable in-ear with swappable plugs and tuning switches.
• Pick beyerdynamic Box if you want an over-ear studio reference headphone for mixing and monitoring where isolation matters.
The FH5s is a hybrid in-ear monitor, and its whole pitch is flexibility. FiiO splits the frequency work across three drivers: a 12mm beryllium-plated dynamic driver handles the low end, a 6mm beryllium-plated dynamic driver covers the mids, and a Knowles TWFK-30017 balanced armature takes the treble. That last driver sits directly in the sound tube, close to the ear, which FiiO says reduces high-frequency loss and extends the top end. The rated frequency range runs from 10Hz to 40,000Hz at 40 ohms.
What makes it stand out for a buyer is the tuning. Three sound adjustment switches give you eight possible sound signatures, so you can nudge the bass, mids and treble toward whatever you're listening to. That's genuinely unusual at this level — most IEMs give you one voicing and that's it. On top of that, the twist-lock swappable plug lets you move between 2.5mm, 3.5mm and 4.4mm terminations, which covers balanced and single-ended sources without buying a new cable.
The semi-open rear cavity is the detail worth understanding. It relieves air pressure on the ear for longer, more comfortable listening and contributes to a larger soundstage — but semi-open means it is not a sealed, isolating design. If you're on a noisy train or in a loud office, that's a real limitation.
Buy the FH5s if you want a portable in-ear you can tune, with swappable plugs and a semi-open character that keeps long sessions comfortable. Skip it if you need maximum isolation, or if you don't want to think about ear tip fit — the seal is what delivers the bass with any IEM.
This is the beyerdynamic DT 770 PRO, a closed-back over-ear studio reference headphone, listed here as an open-box item. The model number is DT770PRO and the version in this listing is the 250 ohm variant, which beyerdynamic describes as ideal for home stereos and studio equipment. That's the key spec: 250 ohms is a high impedance load, and it wants a headphone amplifier or a source with real output power behind it. Plug it into a weak phone jack and you'll likely find it quiet and lean.
The payoff for that impedance is control. With a rated range of 5Hz to 35,000Hz and a low-mass coil and diaphragm assembly, this is a headphone built for detailed reproduction and accurate mixes. It's a closed-back design, so it isolates — which is exactly why it became a fixture in recording studios, post-production houses and broadcast facilities. If you're tracking vocals with a microphone open in the room, or mixing in a space with background noise, closed-back isolation isn't a nice-to-have, it's the point.
Build quality is the other pillar. Beyerdynamic's over-ear studio line has a long-standing reputation for surviving daily professional use, and the cushioned packaging with cable management and impact protection suggests the same mindset. It terminates in a gold-plated 3.5mm jack with a 1/4" adapter, so it works with most headphone amps and interfaces.
Buy the beyerdynamic Box if you want a durable, isolating, over-ear reference headphone for mixing, monitoring or critical listening at a desk with a proper amp. Skip it if you need something portable, or you don't have a source that can drive 250 ohms.
Side-by-Side: Which Should You Choose?
• Best for isolation → beyerdynamic Box. Closed-back over-ear with sound isolation as a listed control feature. The FiiO FH5s has a semi-open rear cavity, which deliberately trades isolation for comfort and soundstage.
• Best for portable listening → FiiO FH5s. In-ear, lightweight, with a twist-lock plug system covering 2.5mm, 3.5mm and 4.4mm.
• Best for studio and mixing work → beyerdynamic Box. Explicitly built for accurate mixes and detailed reproduction, and a long-standing choice in professional rooms.
• Best for use without extra gear → FiiO FH5s. At 40 ohms it's far easier to drive from everyday sources than the 250 ohm beyerdynamic.
• Best for long-session comfort on the go → FiiO FH5s. The semi-open rear cavity relieves ear pressure specifically for extended listening.
• Best for build longevity → beyerdynamic Box. Famed enduring build quality is central to this headphone's identity.
• Best frequency extension on paper → beyerdynamic Box. 5Hz–35,000Hz versus the FiiO's 10Hz–40,000Hz — the beyerdynamic reaches lower, the FiiO reaches higher.
In my opinion, these two aren't really competing for the same buyer, and that makes the call easy. If your work is mixing, monitoring or any situation where you need isolation and a trustworthy reference, I'd buy the beyerdynamic Box — the closed-back design, 250 ohm drivers and studio pedigree line up exactly with that job, provided you have an amp.
If your listening happens on the move or at a desk with ordinary gear, and you want to shape the sound yourself, I'd buy the FiiO FH5s. The hybrid driver array and eight-way tuning give you far more control, and the semi-open design keeps long sessions comfortable.
Before you decide, check the current price on Amazon using the button on this page — pricing and availability change, and that's the one number that should tip a close call.
FAQ
how to open back headphones work
what is open back studio headphones
An open-back studio headphone is one with a vented rear housing, so the driver isn't sealed against your head. The benefit is a more spacious, less boxed-in presentation; the cost is isolation and, often, bass weight. The FiiO FH5s uses a semi-open rear cavity rather than a fully open design, balancing some of that openness against everyday usability.
what are the best open back headphones
There's no single answer, because "best" depends on what you're doing. For portable, tunable listening with a semi-open character, the FiiO FH5s is the more relevant pick here. For desk-based critical work where you need isolation, a closed-back like the beyerdynamic Box is the more sensible tool — isolation and openness pull in opposite directions.
are open back headphones better
Better for what matters to you. Open and semi-open designs like the FiiO FH5s tend to give a wider, more natural soundstage and more comfortable long listening. Closed-back designs like the beyerdynamic Box isolate better and are the practical choice for recording, mixing in noisy rooms, or anywhere you don't want to disturb people around you. Neither is universally better.
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