We compare products from their published specs and features; the verdicts below are our independent editorial opinions.
Updated: 2026-09-19 · 6 min read · Independent comparison
If you want a lighter, more portable planar that's easy to drive and built for daily use, choose HiFiMan SUNDARA Planar Magnetic; if you need a big, open, airy soundstage with swappable earpads and a beefy 106mm driver, choose Monoprice Monolith M1070.
• HiFiMan SUNDARA — biggest strength: A thin, fast planar diaphragm (80% thinner than the HE400 series) paired with a low 37 ohm impedance and 94 dB sensitivity, so it's comparatively easy to drive and detailed.
• HiFiMan SUNDARA — biggest trade-off: It's a relatively sensitive headphone that still wants a decent amp, and the manufacturer explicitly asks for up to 150 hours of burn-in before it reaches its potential.
• Monoprice Monolith M1070 — biggest strength: A large 106mm planar driver with a dual linear symmetry magnet array and an open-back grille for an airy, spacious soundstage — plus two sets of removable earpads in the box.
• Monoprice Monolith M1070 — biggest trade-off: It's a heavy headphone at 20.5 ounces (580g) with a 60 ohm impedance, so it leans on your source and your neck more than the Sundara does.
• Who the HiFiMan SUNDARA is for: Buyers who want a lighter, comfortable all-rounder they can drive from modest gear and carry around.
• Who the Monoprice Monolith M1070 is for: Buyers who want a wide, immersive open-back presentation and don't mind extra weight or a stronger amp.
The Sundara is HiFiMan's take on a planar magnetic over-ear that balances detail with everyday usability. Its headline spec is a diaphragm that's 80% thinner than the HE400 series, which the brand says results in a wider frequency response and a faster, more detailed sound. The rated frequency range runs from 20 Hz up to 75,000 Hz — far beyond what human hearing can register, so the practical takeaway is that the driver has plenty of headroom and shouldn't feel strained in the audible band.
The build leans practical and tough. There's an all-metal headband, a weight-spreading strap for comfort, a matte black finish, and a 3.5mm headphone connector chosen for enhanced durability. It weighs 13.12 ounces, and this latest version ships with improved earpads and an upgraded oxygen-free copper (OFC) cable. A key housekeeping note: HiFiMan asks for a 150-hour burn-in period, and the drivers are sealed — you don't touch or service them.
Buy the Sundara if you want a lighter, more manageable planar you can drive from a wider range of gear and wear for long sessions. Skip it if you refuse to deal with burn-in, or you want the widest possible open-back staging and swappable pads out of the box.
Monoprice Monolith M1070: Who It's For
The Monolith M1070 goes the other direction: bigger driver, bigger sense of space, and a heavier footprint. Its core is a 106mm planar driver using a dual linear symmetry magnet array, which Monoprice describes as delivering accurate sound with low distortion, strong high-end extension, and tight, clean bass. That's a large diaphragm, and it's the spec that most shapes how this headphone behaves.
The open-back grille is the second defining feature. Each earcup lets air pass through to the driver, which Monoprice says puts you in the middle of the performance with a larger soundstage, enhanced imaging, and a more engaging soundscape. If you've only used closed-back headphones, this is the characteristic that will hit you first — an airy, spread-out presentation rather than an in-your-head one. The trade-off of any open-back is straightforward: sound leaks both ways, so it's a poor choice for a noisy commute or a shared office where you need isolation.
Comfort is handled deliberately. Despite the 20.5-ounce (580g) weight, there's a padded, adjustable headband and plush earpads, and Monoprice claims long listening sessions "without a hint of fatigue." The bigger selling point for tinkerers is that the earpads are removable, and the box includes two pairs — memory foam lambskin and memory foam velour — so you can tune the feel (and slightly the sound) without buying anything extra. Impedance is 60 ohms, which is higher than the Sundara's 37, so it wants a more capable source. Monoprice backs it with a 5-year warranty.
Buy the M1070 if you want a wide, immersive open-back soundstage, you like the idea of swapping pads, and you already own (or plan to buy) a solid amp. Skip it if you need isolation, want something light for travel, or you're driving straight from a weak phone jack.
Side-by-Side: Which Should You Choose?
• Best for the widest, most airy soundstage → Monoprice Monolith M1070 (open-back grille and a 106mm driver).
• Best for easier driving from modest sources → HiFiMan SUNDARA Planar Magnetic (37 ohm, 94 dB vs 60 ohm).
• Best for pad-swapping and tuning → Monoprice Monolith M1070 (two sets of removable memory foam earpads included).
• Best for buyers who want a detailed, fast diaphragm → HiFiMan SUNDARA Planar Magnetic (80% thinner diaphragm than the HE400 series).
• Best for users who value a long warranty → Monoprice Monolith M1070 (5-year warranty).
• Best for commuters or shared spaces → neither, strictly speaking — both are wired and the M1070 is open-back, so if isolation is your priority, look elsewhere.
• Best for set-and-forget simplicity → HiFiMan SUNDARA Planar Magnetic, with the caveat that you should expect a 150-hour burn-in.
If I had to pick one, I'd take the HiFiMan SUNDARA Planar Magnetic. In my opinion it's the better all-rounder: lighter on the head, easier to drive at 37 ohms and 94 dB, and built around an all-metal headband and a durable 3.5mm connector. The M1070 is genuinely compelling if your priority is a wide open-back soundstage and you own the amp to feed it — but its weight and 60 ohm impedance make it the more demanding of the two. For most people buying their first serious planar, I'd point to the Sundara and suggest checking the current price on Amazon before deciding.
Not especially. At 37 ohms and 94 dB it's comparatively efficient, but HiFiMan still recommends a decent amp to reach its full potential. If it won't get loud enough, your source is the likely bottleneck.
It helps. At 60 ohms it's harder to drive than the Sundara, so a weak phone jack may struggle. A dedicated amp will get more out of the 106mm driver.
The M1070, on paper — its open-back grille lets air pass through to the driver for a larger soundstage and enhanced imaging. The Sundara is more of an all-rounder than a staging specialist.
Yes, and easily. The supplied pads are removable, and Monoprice includes both memory foam lambskin and memory foam velour pairs, so you can swap or replace them without buying extras.
It's worth planning for. HiFiMan asks for up to 150 hours of playback so the headphones reach their fullest potential — so don't judge them on the first listen.
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