Fiio JadeAudio JT9 Open-Back Planar Headphones

Jade Audio Main Site – JadeAudio Main Site

A Little Technical Stuff:

Headphone type: Open-back planar headphones

• Frequency response: 7Hz–40kHz
• Driver: 3.74 x 3.39 in (95 x 86 mm) planar magnetic driver
• Impedance: 20Ω at 1kHz
• Sensitivity: 95dB/mW at 1kHz
• Sensitivity: 112dB/Vrms at 1kHz
• Weight: Approximately 12.9 oz (365 g), excluding cable
• Cable material: 22AWG high-purity oxygen-free copper
• Cable length: Approximately 4.9 ft (1.5 m)
• Headphone connector: Dual 3.5mm TS
• Audio plugs: 3.5mm and 4.4mm
• Colors: Black and deep brown

-MRSP: Universal fit $159.99 – $169.99?

Greetings from the Audio Rabbit Hole. We are back again with another product to highlight, and this time it is the FiiO JadeAudio JT9 open-back planar headphones. JadeAudio is another FiiO sub-brand, similar in spirit to Snowsky, whose Oak Nano I reviewed not long ago. Apparently, FiiO has reached the “we need more brand tunnels inside the rabbit hole” phase, and honestly, that tracks.

Special thanks to FiiO for the opportunity to review the JadeAudio JT9; I appreciate it.

FiiO and its related brands have been catching me off guard lately. Years ago, when I was first introduced to FiiO, I mostly thought of them as a budget-friendly company with decent sound. There was always better-sounding gear available, and their DAPs were usually backups to whatever flagship player I was carrying at the time, the audio equivalent of “you can come, but you are riding in the trunk.”

These days, that view has changed quite a bit. My primary DAP right now is the flagship FiiO M27 Ti, and I genuinely enjoyed the budget-minded Oak Nano. Then along comes the JT9, which, I will say right up front, surprised me with the level of sound it delivers. I was prepared for “pretty good for the money.” The JT9 apparently showed up with a clipboard and asked who authorized my low expectations.

I have a question mark next to the $159.99 retail price above because, at the time of writing, I could only find one U.S. retailer carrying the JT9, and that was their listed price. I am sure more retailers will pop up soon, since I received these a little before release, but unfortunately my schedule decided to throw itself down a staircase and prevented me from getting this review out as quickly as I would have liked.

So now you understand my apprehension: a $159.99 open-back planar headphone. That sentence alone sounds like the setup to an audiophile prank. My immediate thought was, “Okay, what sounds like ass here?” But surprisingly, that has not been my experience at all. Quite the opposite, actually. So let’s break this product down before my expectations file a formal complaint.

A Little Marketing Hype, straight from their site, no edits:

Product highlights

• Proprietary 3.74 x 3.39 in (95 x 86 mm) planar magnetic driver
• Ultra-thin 0.000039 in (1 μm) diaphragm
• Patented sapphire and aluminum dual-coating technology
• Patented uniform magnetic field design
• 28nm-grade conductive voice-coil manufacturing process
• 95dB/mW sensitivity at 1kHz
• 20Ω impedance at 1kHz
• Approximately 12.9 oz (365 g) without cable
• Foldable multi-axis ergonomic design
• 22AWG high-purity oxygen-free copper cable
• 5mm single-ended and 4.4mm balanced cables included
• Hi-Res Audio certified

WHAT’S IN THE BOX: 

• JadeAudio JT9 headphones
• Storage case
• 5mm single-ended headphone cable
• 4mm balanced headphone cable
• 35mm male to 3.5mm female adapter
• Quick start guide

Unboxing and Accessories

Out of the gate, I have to throw a little shade at FiiO and JadeAudio. Whoever designed the logo made it harder to read than it needed to be, because on the box and headphones it looks more like “dade audo” than JadeAudio. Dade is a county in Florida, and I am fairly sure there is no connection there, so we are left with a branding choice that makes me tilt my head and squint.

The box is simple, with a picture of the product, the model name, some Chinese writing, and all of the FiiO brand names listed.

Lift open the box flap, and you see a black vinyl case that reminds me of a sunglasses case, with FiiO emblazoned on the front.

Along with the case, FiiO includes two zip-lock packages containing the cables: one 3.5mm single-ended headphone cable and one 4.4mm balanced headphone cable. You also get a 6.35mm male to 3.5mm female adapter and the quick start guide. It is a simple package, but it covers the essentials.

Once you unzip the FiiO case, you see the headphones folded neatly inside. That is interesting because making an open-back headphone transportable and foldable is not the usual move.

For anyone newer to the hobby, open-back headphones generally use an outside grille or vented structure that lets air and sound pass through instead of isolating you from the room. That usually gives the listener a more open presentation, but it also means people nearby can hear what you are playing.

Turning that kind of headphone into a portable solution is unusual, and that makes the JT9 more interesting right away.

The included dual 22AWG oxygen-free copper cables, one 3.5mm single-ended and one 4.4mm balanced, have protective covers on the tips and come with Velcro cable ties. FiiO also includes a 6.35mm adapter and a waterproof storage case.

There you have it: a straightforward unboxing, a practical accessory set, and one unusually portable open-back planar headphone.

Build Quality and Fit:

I will be honest: I am so accustomed to higher-tier build quality that I was a little underwhelmed by the feel of these at first. Then I slapped myself back into reality and remembered I didn’t pay thousands for them. The JT9 is basically made of plastic and aluminum. The plastic does not feel cheap, but it is still plastic, and there is no need to pretend otherwise.

I know that sounds harsh, but I also want to be clear: FiiO seems to have spent the money where I am happiest they spent it, on the drivers and sound quality. I want to dive into those details for a minute. Yes, I am very straightforward in my reviews, and I can be harsh when I feel it is justified, but I also give credit where credit is due.

I want to talk about the driver for a second. The JT9 uses a 95 x 86 mm planar magnetic driver with an ultra-thin 1 μm PET diaphragm and sapphire/aluminum dual plating, created through a 28 nm chip-level vacuum sputtering process. The frequency response is 7 Hz–40 kHz, with an impedance of 20 Ω at 1 kHz. Sensitivity is rated at 95 dB/mW at 1 kHz and 112 dB/Vrms at 1 kHz.

The JT9 has a fairly large planar driver by headphone standards, and the comparison gets more interesting when you look around the market. On paper, the JT9’s 95 x 86 mm driver, 1 μm diaphragm, 20 Ω impedance, and 95 dB/mW sensitivity put it surprisingly close to FiiO’s own FT1 Pro, while coming in at a lower asking price.

It also does not look wildly outclassed next to familiar affordable planar benchmarks like the HIFIMAN Sundara. Specs do not guarantee great sound, because spec sheets can lie with a straight face, but the JT9 at least shows up with a driver package that looks serious for the money.

I will save the sound impressions for the actual sound section, but this is where the planar comparison starts to get interesting.

Fit and comfort are where the JT9 starts making more sense as a full-size headphone you can actually live with for long sessions. At 365 grams without the cable, it is exceptionally light for a headphone using a 95 x 86 mm planar magnetic driver. That matters, because “full-size planar” and “lightweight” do not always show up to the same party.

The multi-axis adjustable headband spreads clamp force evenly, which helps avoid the usual hot spots on top of the head, while the 3D asymmetrical earpads contour slightly to better match the shape of the face.

The pads have an opening of roughly 65 x 45 mm with about 20 mm of depth, so they feel more like a proper over-ear design than a cramped ear-smasher. The plush, breathable fabric also helps during longer computer or desk sessions by keeping heat and sweat buildup under control.

Glasses compatibility is also strong here. The padding and clamp distribution do a good job of maintaining a seal without turning eyeglass frames into tiny punishment rails on the side of your head.

The foldability is another practical win. The cups rotate 90 degrees and collapse inward flat enough to fit into the included waterproof storage case, which makes the whole “portable open-back planar” idea feel less like marketing nonsense and more like an actual use case.

The cable ergonomics are also better than expected. The dual-entry 3.5 mm connectors are straightforward, and the rubbery, grooved cable insulation keeps the cables pliable while reducing microphonics, so cable rub doesn’t constantly announce itself in your ears.

Review Setup:

I crafted the review using a few key sources: the Pixel 11 Pro, paired with an Astell & Kern HC5 dongle, A&K SP4000T and the Fiio M27 Ti DAP. For my sample music, I explored a range of formats, including 320 kbps, FLAC, and 24-bit audio, as well as streaming services like Tidal, Spotify Lossless.

Moving on to the sound section….

I have been critical of some aspects of this headphone, but I think part of that comes from spending so many years immersed in flagship gear. Even after 15 years of writing, I am still learning how to reset my expectations and meet a product where it actually lives. With that in mind, it is time to talk about where the JT9 starts pushing back against my skepticism: sound quality.

This is where the JT9 earns its keep: sound quality.

Out of the gate, do not expect heavy coloration. The JT9 reproduces the quality of the music without pushing the frequencies out of their lanes, which makes for an easy, enjoyable listen. These headphones have gotten more ear time than almost anything else in my collection, including IEMs, closed-back headphones, and just about everything in between.

Simple definition of the JT9 in a few words: balanced, musical, and very good at accurately portraying the music. If there is a heavy bass line, you hear it. The JT9 actually has more bass than most open-back planar headphones I have heard, which is not usually where these things show up flexing. Feed the JT9 a hi-res FLAC file, and the difference between that and lower-resolution files is clearly distinguishable.

The bass continues to impress me. If the track has bass, the JT9 knows where it is and presents it. If it is a bass-heavy track, it delivers a solid amount of bass. If the track is bass-light, you can still hear the bass staying in its own lane and filling in exactly where it should.

In other words, the bass is present and physical enough to matter, but it always stays in control. For an open-back planar, it is surprisingly present, almost like the JT9 remembered bass was invited to the meeting and actually saved it a chair.

In the mids, the vocals are clear and textured. I have never detected a hollow or overly sterile tonality in the midrange. The highlight here is the staging and separation.

The air around the instruments is very well defined, with each element having its own space instead of everyone trying to crowd the same tiny elevator. The Eagles, Hell Freezes Over, Hotel California was next level.

Even when the music gets busy, the JT9 does not seem to have any issue keeping up, allowing for fast transients and a clean sense of control.

Moving on to treble, the JT9 has good treble extension that reveals detail very well. There is energy and crispness here, but it is not trying to sandblast your ears for sport. It is not intolerable to me or fatiguing. As I said before, I can listen to these for extended periods without fatigue.

I only tried the stock pads, and adding different pads could introduce other variables, such as the treble deciding to take a casual walk along the jagged edge.

One more thing worth mentioning before we wrap up the sound section is drivability. For an open-back planar headphone, the JT9 is remarkably easy to drive. With its 20-ohm impedance and 95 dB/mW sensitivity, it does not behave like the kind of planar that demands a desktop stack, a dedicated power station, and a written apology to your wallet.

In my use, the JT9 reached good listening volumes from portable sources without much drama. A small USB-C DAC/amp dongle, such as my A&K HC5,  is more than enough to get them moving, and that makes the JT9 much more practical than I expected from an open-back planar design. It keeps the planar speed and control without requiring the usual planar power commitment, which is always appreciated because my desk already has enough cables trying to form a local government.

That said, the JT9 is not completely source-blind. It runs fine from simple gear, but it still responds well when connected to a more capable source. Using the included 4.4mm balanced cable with something like a stronger DAP or dedicated amplifier gives the driver a little more breathing room, especially when the music gets busy. The bass feels a bit tighter, the separation stays cleaner, and the overall presentation feels more composed.

So the takeaway is simple: the JT9 is portable-source friendly, but it still rewards better gear. You do not need a giant desktop stack to enjoy it, but if you have one, the JT9 will not turn down the invitation.

You might want to own the FiiO JadeAudio JT9 if: 

• You want an affordable open-back planar headphone that sounds balanced, musical, and honest. 

• You like a spacious presentation with strong separation, where instruments are easy to place and the mix does not collapse into one big audio casserole. 

• You prefer bass that shows up when the track calls for it, has more presence than expected for an open-back planar. 

• You enjoy clear, textured mids with vocals that sound natural instead of being flattened into review-sample cardboard. 

• You want treble with detail, energy, and extension, but not the kind that makes cymbals feel like they are filing paperwork directly inside your skull. 

• You want a planar headphone that is easy to drive from portable sources, but still has enough room to improve when connected to better gear. 

• You appreciate a practical package with 3.5mm and 4.4mm cables, a storage case, and a foldable design that makes the JT9 easier to live with than most open-back headphones.

In Closing

 Overall, the FiiO JadeAudio JT9 is a strong reminder that affordable open-back planar headphones do not have to feel like a compromise parade. It is lightweight, practical, easy to drive, and more capable than I expected at this price.

The JT9 leans toward balance, clarity, separation, and an honest presentation of the recording. Bass is more present than I expected for an open-back planar, the mids are clear and textured, and the treble has good detail and energy without becoming fatiguing with the stock pads.

The build is not luxury-grade, but it works. The folding design, storage case, 3.5mm cable, 4.4mm balanced cable, and 6.35mm adapter make the JT9 feel like a genuinely practical package rather than a spec-sheet experiment.

If you want a balanced, musical, easy-to-drive open-back planar with good staging, controlled bass, and clear detail, the Fiio JadeAudio JT9 is easy to recommend. It is not pretending to be a flagship, but it delivers enough of the planar experience to make its price feel very reasonable.