If you want wired in-ear monitors with interchangeable sound profiles and a metal housing, choose HiFiGo Kefine Klean High-Fidelity; if you need an in-line microphone and button controls, choose QJF AK9. For airplane listening, I’d lean toward the Klean for its choice of two nozzle sound profiles, while the AK9 is the more practical pick if hands-free calls matter.
Neither is a wireless headset, and neither lists active noise cancellation. These are wired in-ear options for listeners comparing head phones for airplane use, not noise cancelling over ear headphones for airplane travel.
• HiFiGo Kefine Klean High-Fidelity: A 10 mm DLC dynamic driver, two interchangeable nozzles, and a metal alloy housing are its standout features. The trade-off is that it has no listed in-line microphone or call controls.
• QJF AK9: An 11 mm dynamic driver, passive noise isolation, and an in-line microphone with a button suit calls and everyday device use. Its trade-off is a plastic housing and no interchangeable sound nozzles.
• For adjustable sound and a metal build: Choose the Klean.
• For calls and simple button control: Choose the AK9.
• For either pick: Both are wired in-ear monitors with a detachable 0.78 mm 2-pin cable and a 3.5 mm plug.
The Klean is the more customizable of these two earphones. It uses a 10 mm dynamic driver with a DLC diaphragm, a lightweight, mechanically strong material intended to support clarity and detail. The listed frequency range is 20 Hz to 20,000 Hz. Those figures describe its audio design, but they don’t tell you exactly how it will sound with every recording or device.
Its two interchangeable nozzles offer a useful point of difference: the silver nozzle is described as warmer and smoother, while the black nozzle is intended for a brighter presentation. That gives listeners a way to adjust the sound character without changing earphones. On a flight, that flexibility may be appealing if you listen to varied music or prefer a less bright profile for a long listening session. This is still passive in-ear listening, though, not active noise cancellation.
How We Research
We compare products from their published specs and features; the verdicts below are our independent editorial opinions.
Updated: 2026-10-20 · 7 min read · Independent comparison
Who should skip it: Skip the Klean if an in-line microphone and button controls are essential for taking calls or adjusting playback.
The AK9 is the more function-focused option. Its 11 mm dynamic driver is slightly larger by the stated measurement than the Klean’s 10 mm driver, but driver size alone does not establish which earphone sounds better. The listed specifications include a 20,000 Hz frequency response, 20-ohm impedance, and 105 dB sensitivity. These are useful reference points, not a guarantee of a particular listening experience.
Its strongest everyday feature is the in-line microphone and push-button control. If you want to answer hands-free calls or operate music without reaching for your connected device, the AK9 has controls the Klean’s listed feature set lacks. The 3.5 mm plug also makes it a wired option for compatible smartphones, tablets, laptops, gaming devices, and MP3 players. Check that your device has a suitable 3.5 mm connection; the supplied information does not list a wireless option.
The AK9 uses a closed in-ear design intended to provide passive sound isolation, along with a lightweight plastic housing and an ergonomic fit. That can make it a practical candidate for travel and routine listening, including as wireless earbuds for airplane searches—though it is not wireless. Its cable is detachable at a standard 0.78 mm 2-pin connection, and the manufacturer lists a two-year warranty. Unlike the Klean, it does not include interchangeable nozzles for choosing between stated sound profiles.
Who should skip it: Skip the AK9 if a metal housing or the option to swap between two nozzle sound profiles matters more than call controls.
• Best for choosing between two stated sound profiles → HiFiGo Kefine Klean High-Fidelity. The silver nozzle is described as warmer and smoother; the black one as brighter.
• Best for hands-free calls → QJF AK9. It lists an in-line microphone and a button control; the Klean’s supplied features do not list either.
• Best for a metal housing → HiFiGo Kefine Klean High-Fidelity. Its housing is metal injection-molded alloy, with screw-secured front and back sections.
• Best for listed passive sound isolation → QJF AK9. Its closed in-ear structure is described as isolating ambient sound. Neither product lists active noise cancellation.
• Best for listeners who want a detachable cable → Tie. Both use a 0.78 mm 2-pin connection, so each allows the cable to be detached.
• Best for airplane listening with a 3.5 mm connection → Either, with a caveat. Both are wired in-ear options; confirm your device has a compatible jack or suitable connection before traveling.
• Best for a supplied hard carrying case and multiple eartip sizes → HiFiGo Kefine Klean High-Fidelity. Its listed contents include a case and three sizes of eartips.
• Best for button control while gaming or using a phone → QJF AK9. Its inline button and microphone are useful distinctions if you want more than a basic wired listening connection.
In my opinion, I’d choose the HiFiGo Kefine Klean High-Fidelity for airplane listening if I wanted wired in-ears, a metal housing, and two nozzle options for adjusting the sound character. Its main compromise is the absence of listed call controls.
I’d choose the QJF AK9 instead if its microphone, button control, and stated passive isolation better match my daily routine. For my airplane use, the Klean’s adjustable profiles make it the more compelling pick, but neither is a substitute for a wireless headset or active noise-cancelling over-ear headphones.
Think about your device connection first. Both products are wired and list a 3.5 mm jack, so they are not wireless earbuds for airplane use. Some travel devices may not have a matching jack. Confirm how you’ll connect before packing either pair; no wireless connectivity is listed for either model.
Separate passive isolation from noise cancellation. The AK9 is described as having a closed in-ear structure that provides passive sound isolation. The Klean lists passive noise control. Neither sheet describes active noise cancellation. If reducing cabin sound is your main priority, don’t assume either pair will function like noise cancelling over ear headphones for airplane travel.
Consider what you do while listening. If calls and playback control matter, the AK9’s inline microphone and push button are concrete advantages. If you’re mainly listening to music and want a choice between warmer and brighter nozzle profiles, the Klean gives you that option instead.
Look at the replaceable parts and included accessories. Both have detachable 0.78 mm 2-pin cables. The Klean also lists a hard case, three eartip sizes, and interchangeable nozzles. The AK9’s supplied details emphasize the earphones and its inline controls. For either product, consult the included product information for the items provided with the model you’re considering.
No. Both are listed as wired earphones with a 3.5 mm jack. Neither product sheet lists wireless connectivity, so check that your travel device supports the connection you plan to use.
Which is better for airplane noise, the Klean or the AK9?
The product information describes the silver nozzle as warmer and smoother and the black nozzle as brighter. That makes the Klean the more adjustable option on paper; the AK9 does not list interchangeable nozzles.
The QJF AK9. It lists an in-line microphone and button control for calls and music operation. The Klean’s provided features do not list an in-line microphone or call-control button.
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