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We compare products from their published specs and features; the verdicts below are our independent editorial opinions.
Updated: 2026-09-19 · 7 min read · Independent comparison
• Monoprice Monolith M1570 — biggest strength: A large 106mm planar driver with a dual linear symmetry magnet array, tuned for accurate, low-distortion sound with tight bass and strong treble extension, plus a genuinely open grille design for a wide, immersive stage.
• Monoprice Monolith M1570 — biggest trade-off: It's a heavy, wired, open-back headphone (listed at 4.5 pounds) with no swappable cable plugs mentioned and a narrower 20 Hz–20 kHz range than its rival.
• FiiO FT5 — biggest strength: A 90mm planar driver with a 6μm diaphragm, 20 neodymium magnets per driver, a magnesium alloy frame, and high sensitivity (110dB/1Vrms) that makes it easy to power from modest sources.
• FiiO FT5 — biggest trade-off: It leans toward a "musical" tuning by design, and its cable terminations (dual 3.5mm on the headphone end) are less universal than a plain single-entry cable if you like to swap aftermarket cables.
• Who the M1570 is for: Listeners who want a spacious, detail-forward open-back and don't mind a heavier build.
• Who the FT5 is for: Buyers who want an easy-to-drive planar with a huge frequency range, lighter construction, and a flexible plug system.
The M1570 is built around a single big idea: a 106mm planar magnetic driver paired with a dual linear symmetry magnet array. In plain terms, that's a lot of driver surface area driven by a magnet structure designed to keep the diaphragm moving evenly. The result, per the specs, is low distortion, tight and clean bass, and high-frequency extension that stays controlled rather than sharp. If you've only heard dynamic headphones, a large planar like this is the kind of design people reach for when they want bass that stops and starts on command instead of lingering.
The open-back grille is the other headline feature. Because air passes through each earcup to the driver, the soundstage opens up, imaging gets more precise, and you feel more like you're sitting inside the performance rather than in front of it. That's the classic open-back trade: you gain space and airiness, and you give up isolation. The M1570 is explicitly a sound-isolation-free design, so it's a poor fit for noisy rooms, shared offices, or commutes. It's a stay-put, listen-at-home headphone.
Comfort and ownership details matter here too. It uses a plush padded headband, and the earpads are removable, which is a real plus for long-term ownership. Monoprice even ships two pairs of memory foam pads — one lambskin and one velour — so you can tune the feel and, to a degree, the sound without buying anything extra. The build is wired over-ear with a 3.5mm jack, and it's listed at 4.5 pounds, which is heavy enough that you'll want to think about how you wear it. The frequency range is 20 Hz–20 kHz and the warranty is listed at 5 years.
Buy it if you want a big-driver, open-back planar with removable pads and a focus on accuracy and stage. Skip it if you need isolation, want something light for travel, or expect a swappable-plug cable out of the box.
The FT5 takes a different route to "planar." Its driver is 90mm with a 6μm ultra-thin diaphragm — FiiO describes that as roughly a tenth of the thickness of a human hair. Thin diaphragms generally mean quicker response and finer detail, and FiiO pairs it with a micron-level aluminium-silver alloy coil, which the brand frames as the sweet spot between acoustic performance and how easy the headphone is to drive. Twenty neodymium magnets per driver keep the force on that diaphragm balanced and precise.
The headline spec for most buyers is sensitivity and impedance. At 110dB/1Vrms (96dB/mW) and 36Ω, the FT5 is explicitly designed to be easy to power. That matters: it means you can get good output from a phone with a dongle, a laptop, or a modest desktop amp, without needing a high-gain powerhouse. Compare that to the M1570's data, which gives no sensitivity or impedance figures at all — a buyer shopping the Monoprice has to assume it wants more current behind it. If you want a planar that just works with what you already own, that gap is the FT5's strongest argument.
Frequency response is the other standout: 7 Hz–40 kHz. That's far wider at both ends than the M1570's 20 Hz–20 kHz. In practice, the deep-end figure suggests sub-bass content you can feel more than hear, and the top-end figure suggests headroom well past what humans perceive — more about air and refinement than audible treble. FiiO also describes the tuning as aiming for a natural, musical presentation.
Buy it if you want an easy-to-drive, lightweight planar with a wide range and a flexible plug system. Skip it if you specifically want the biggest driver and the most spacious open-back presentation, or you value a longer warranty term.
Side-by-Side: Which Should You Choose?
• Best for easy amplification → FiiO FT5. Its 36Ω impedance and 110dB/1Vrms sensitivity mean it plays loud from everyday sources; the M1570 publishes no such figures.
• Best for the widest frequency range → FiiO FT5. 7 Hz–40 kHz versus 20 Hz–20 kHz on the M1570.
• Best for the largest driver and open-back stage → Monoprice Monolith M1570. A 106mm planar driver and a grille designed for airiness and imaging.
• Best for cable and plug flexibility → FiiO FT5. Swappable 3.5mm/4.4mm plugs plus 6.35mm and XLR-4 adapters included.
• Best for pad-swapping out of the box → Monoprice Monolith M1570. Two memory foam pad sets (lambskin and velour) included, and the pads are removable.
• Best for lighter, travel-friendlier construction → FiiO FT5. Magnesium alloy frame with a leather case and velvet bag; the M1570 is listed at 4.5 pounds.
• Best for longer warranty coverage → Monoprice Monolith M1570. Warranty is listed at 5 years versus 1 year for the FT5.
• Best for quiet listening in shared spaces → neither. Both are open-back and neither isolates; if that's your priority, look elsewhere.
In my opinion, the FiiO FT5 is the smarter buy for most people. It's easier to drive, lighter, and gives you a wider 7 Hz–40 kHz range plus a genuinely useful plug system and a full accessory kit — all things that make it work with gear you already own. I'd pick the Monoprice Monolith M1570 only if you specifically want the bigger 106mm driver, the roomier open-back presentation, the included dual pad sets, and the longer 5-year warranty, and you're prepared to feed it properly and live with its weight. For a first planar, or for a headphone that just plugs in and sings, the FT5 is my recommendation.
Yes, based on the published specs. The FT5 is rated at 36Ω with 110dB/1Vrms sensitivity, which FiiO describes as easy to power. The M1570's data sheet lists no sensitivity or impedance, so plan on giving it more amplification.
The FiiO FT5, by a wide margin: 7 Hz–40 kHz versus 20 Hz–20 kHz for the M1570. The FT5's deeper low-end figure suggests more sub-bass presence, and its top end extends well beyond audible limits.
Both include two pairs of pads. The FT5 goes further with a swappable plug system (3.5mm and 4.4mm) plus 6.35mm and XLR-4 adapters. The M1570 lists removable earpads and a 3.5mm jack but no swappable plug setup.
Neither. Both are open-back designs, so they leak sound in and out and provide no meaningful isolation. These are headphones for a quiet room, not for travel or shared spaces.
Both are sold on Amazon, and prices change, so use the "Check latest price on Amazon" button on this page to see the live figures before you decide.
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