Over-Ear Headphones

FiiO JadeAudio JT9 Review: Are These the Best Budget Planar Magnetic Headphones?

The $160 FiiO JadeAudio JT9 planar headphones deliver deep bass and spacious sound, but can their bright treble spoil an otherwise excellent value?

W. Jennings

Updated

5 days ago

2026 FiiO JadeAudio JT9 Open-back Planar Magnetic Headphones in Brown and Black

While much of the headphone industry seems focused on wireless models and increasingly sophisticated active noise cancellation (ANC), another trend has been developing rather quietly. Planar magnetic drivers are far more common than they were a decade ago, and prices have dropped considerably. Gaming headsets such as the Audeze Maxwell and Sony’s PlayStation Pulse Elite, which uses planar magnetic technology developed by Audeze, have helped introduce the technology to a much broader audience.

Planar magnetic headphones are now available across a wide range of price points, although the budget category remains dominated by dynamic drivers. There’s a simple reason for that: basic 40 mm dynamic drivers are incredibly inexpensive to manufacture. Armed with a soldering iron, some wire, a 3.5 mm plug, and a 3D printer, it’s theoretically possible to assemble a functioning pair of dynamic headphones for less than $10 in parts and a few hours of your time. Factor in the economies of mass production, and it’s easy to understand why the bargain bins at big-box retailers aren’t overflowing with planar magnetic headphones.

FiiO and its budget-focused JadeAudio brand have built a reputation for delivering impressive performance without asking consumers to empty their wallets. The JadeAudio JT9, available from Apos Audio for $159.99, continues that tradition by making planar magnetic technology accessible to a much wider audience.

Bucking the industry’s wireless trend, the JT9 is a wired, open-back headphone with no Bluetooth or ANC. The emphasis is squarely on sound quality rather than electronic conveniences, which is refreshing in a market increasingly obsessed with features that don’t necessarily make music sound better.

Apos Audio kindly provided a pair of FiiO JadeAudio JT9 headphones for this review.

Build & Fit

The JT9 has an open-back, folding design with a multi-axis yoke. Its earcups fold flat and rotate to fit inside the included semi-rigid carrying case. The case is thicker than most and uses a half-clamshell design that stores the headphones folded instead of with the cups folded flat, like most of the ANC models available today. It doesn’t take up any more real estate in a pack but needs a slightly different-shaped compartment to accommodate it.

The construction uses a mix of metal and plastic. The metal headband and adjustment points provide structural support, while much of the cup and yoke assembly is polymer. This keeps weight (365 grams) and cost down, but it does not give the JT9 the dense, premium feel of more expensive headphones. The polymer material is heavy enough that durability concerns are mitigated for all but the most abusive headphone users.

The cups are capsule-shaped, with the longer dimension on the vertical axis allowing for the large planar drivers. The cups are fairly thin from front to back, as the planar driver doesn’t require a large excursion to work, making for a fairly compact cup design. The grilles use a tri-lobed port design that looks like the old Dodge Fratzog logo of the late ’60s. The cups have 3.5 mm ports at the bottom for the provided cables.

The suspension uses a padded headband and a multi-axis adjustment system with 90° folding rotation, 35° rotation on the horizontal axis, 45° rotation on the vertical axis, and roughly 38 mm of adjustment travel on the headband. Clamping force is moderate, with enough force to stay put when moving vigorously (I’ve been known to dance while listening) but low enough to avoid being fatiguing during longer listening sessions. One caveat is that those with small heads may need to bend the band, as it starts out fairly large, and children or small adults may find it a bit loose by default. With the metal band, that’s an easy correction.

The pads are perforated and asymmetrical, with a shape intended to follow the angle of the face and ear. Pad geometry matters acoustically as well as ergonomically: it affects seal, driver distance, and the headphone’s tonal balance. Replacement pads should not automatically be assumed to sound identical.

The JT9 includes two 6-foot cables: one with 3.5 mm connections at both ends and the other with 3.5 mm at the cup end and a 4.4 mm balanced connection at the source end. A 6.35 mm adapter is also provided for use with the 3.5 mm cable. The cables are constructed of 22 AWG high-purity oxygen-free copper, made with strands of several diameters.

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FiiO JadeAudio JT9 Specifications:

Type: Wired, open-back, over-ear planar magnetic headphones
Driver: 95 x 86 mm planar magnetic
Diaphragm: 1 μm PET with sapphire and aluminum dual coatings
Voice Coil: 28 nm-grade manufacturing process
Magnetic System: Patented uniform magnetic field design
Frequency Response: 7 Hz – 40 kHz
Impedance: 20 ohms at 1 kHz
Sensitivity: 95 dB/mW (112 dB/Vrms) at 1 kHz
Recommended Amplifier Power: 300 mW for maximum performance; not a minimum requirement
Weight: Approximately 365 grams (12.9 ounces), excluding cable
Construction: Metal headband with polymer earcups and yokes
Design: Foldable, multi-axis adjustable earcups
Connections: Dual 3.5 mm headphone inputs
Included Cables: 3.5 mm single-ended and 4.4 mm balanced
Standard Cable Length: Approximately 1.5 meters (4.9 feet)
Cable Material: 22 AWG high-purity oxygen-free copper
Accessories: 6.35 mm adapter and protective carrying case
Certification: Hi-Res Audio
Colors: Black and Deep Brown (availability varies)

Inside the FiiO JadeAudio JT9

The JT9 uses a 95 x 86 mm planar magnetic driver with a 1 μm PET diaphragm featuring dual sapphire and aluminum coatings. Aluminum provides electrical conductivity, while sapphire adds stiffness without adding much weight. JadeAudio discusses its 28 nm manufacturing process for the conductive voice coil. This is similar to the cleanroom processes used in semiconductor manufacturing and represents a major investment for the company. All of this is done to create a more uniform magnetic field and more linear diaphragm motion, thus reducing noise and distortion.

The drivers have a nominal impedance of 20 Ω and a sensitivity of 95 dB/mW, which puts them in the easy-to-drive category. Most portable devices and dongles should have no issue powering the JT9 appropriately. JadeAudio recommends sources capable of providing 300 mW of output power to fully realize the JT9’s capabilities. This is a headroom recommendation rather than a minimum requirement, which is worth noting because the JT9 worked well with some sources below that threshold.

Frequency response is listed at 7 Hz to 40 kHz, which should provide plenty of low-end power. However, with planar drivers relying on fast, small movements, bass performance can be a stumbling block for the design, so the listening notes will help confirm how well the JT9 handles the low end.

Listening

Planar headphones are often criticized for both a lack of bass depth and a lack of impact in the lower frequencies, as a driver that moves a tiny distance very quickly can struggle to produce the same volume of bass as a dynamic driver with much greater excursion. The depth complaint cannot be leveled against the JT9. Sub-bass has good extension and quantity, and while certainly not as potent as some headphones, it would be difficult to find the sub-bass lacking. The lows are tightly controlled, and while they add some warmth to the overall sound, they are not overly thick or boomy.

Mid-bass is cleanly presented, with some slam to the kick drum, but here, some of the impact limitations commonly associated with planars are evident. The JT9 is unlikely to jar listeners out of their seats when the cannon fires on AC/DC’s “For Those About to Rock (We Salute You)” or the bottom drops out on James Blake’s “Limit to Your Love.” What is there, however, is pleasant and well controlled.

The lower midrange flows cleanly from the mid-bass, with no obstruction or bleed and a good amount of warmth and weight. This gives low strings and lower vocals good timbre and allows voices to cut through the mix without pushing them in front of it. There is a slight dip in the true midrange (roughly 1-2.5 kHz) that limits violins somewhat, but electric guitars still sound appropriately gravelly when pushed hard, while acoustic guitars sound clean and crisp.

There is a lift that starts in the upper midrange and continues into the lower treble that will be divisive. Depending on the source and track, this lift can improve clarity and help strings and vocals sound more realistic, or it can push things over the edge and sound a bit too hot and strident.

Warmer sources paired better here, and tracks mastered on the edge of sibilance will certainly reveal it, regardless of source pairing. This is not so much a knock against the JT9 as a reminder that source gear and recording quality cannot be overcome by a headphone.

The lower treble continues the lift of the upper midrange before falling back around the 7 kHz mark. Percussion has good snap, and cymbals have plenty of energy as well. Overall treble detail is good, with enough air and sparkle to sound open and expansive, although potentially fatiguing for more sensitive listeners.

That open top end also helps with the soundstage, which has good dimensions in both width and depth, along with enough height to create a three-dimensional presentation. To my ears, width is slightly greater than depth, but both are good, and the stage feels neither crowded nor overly stretched. Seating the orchestra is straightforward, as instrument and stereo separation are both quite good. This also benefits imaging, with movements easily tracked through space and individual locations clearly defined.

The Bottom Line

Not long ago, headphones built around large planar magnetic drivers like the JT9’s 95 x 86 mm design often cost more than $500, with many priced considerably higher. At $159.99, the FiiO JadeAudio JT9 makes that technology accessible to a much wider audience, but affordability only represents good value when sound quality, comfort, and construction measure up. Fortunately, the JT9 delivers on all three. Although the build relies heavily on polymer, nothing feels flimsy or fragile, and the padded earcups, moderate weight, and comfortable clamping force make extended listening sessions enjoyable.

The JT9’s V-shaped sound signature combines satisfying bass extension, a touch of warmth, and energetic treble with impressive clarity and separation. Bass impact isn’t quite as visceral as some dynamic headphones, and the elevated upper midrange and treble can become fatiguing with brighter sources or aggressively mastered recordings. Source matching matters, although the JT9 is easy enough to drive with many portable devices and affordable dongle DACs. Its ability to benefit from better amplification and source components also makes it an appealing option for newcomers looking to upgrade their systems over time.

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Who should buy the JT9? Listeners who want an affordable introduction to planar magnetic headphones without sacrificing comfort, detail, or the ability to upgrade their source equipment. Its open-back design makes it better suited to home listening than commuting, crowded offices, or watching television beside a sleeping partner. Sound leakage and minimal isolation are simply part of the deal.

At less than $200, the JT9 delivers performance that would have been difficult to find at this price only a few years ago, and it compares favorably with some considerably more expensive planar headphones I’ve heard. It isn’t perfect, particularly for treble-sensitive listeners or those seeking powerful bass impact, but its combination of sound quality, comfort, and construction makes it an excellent value. FiiO has built its reputation on making serious audio affordable, and the JadeAudio JT9 gives budget-conscious listeners another compelling reason to pay attention.