Test Edifier STAX Spirit S10 (2026): the planar TWS put to the test

The planar magnetic transducer requires a deeper housing than classic dynamic drivers, and Edifier does not hide this compromise. Each earbud weighs 8,2 g and measures approximately 24 mm outside the nozzle, with a rear body of 16 mm in diameter that protrudes noticeably from the ear pavilion. The charging case follows the same logic: 62 x 48 x 28 mm for 58 g, noticeably bulkier than a Sony WF-1000XM5 or Bose QC Earbuds II case.

The geometry of the silicone tip (three sizes provided) remains conical and short, which limits deep insertion and leaves part of the transducer body resting externally on the tragus. During continuous sessions, the fit evolves noticeably:

• 1 h of wear: no notable discomfort, stable support even while walking
• 2 h of wear: slight pressure on the tragus, perceptible but tolerable
• 3 h of wear: necessity to remove and reposition the earbud at least once, particularly on the right side

Measured against the Harman IEM 2019 curve, the signature of the STAX Spirit S10 deviates noticeably from the neutral target. The sub-bass shows a shelf of +2 dB below 100 Hz, the midrange between 800 Hz and 2 kHz is recessed by about 1,5 dB, and a peak of +3 dB appears around 8 kHz before a dip of 2 dB around 3 kHz, an area usually sensitive for voice perception.

This profile favors a wide soundstage and clear separation between sound planes, a classic advantage of the planar magnetic for the reproduction of percussive transients. The dip at 3 kHz slightly attenuates vocal presence, which explains the qualifier 'not very consensual' noted elsewhere without ever being quantified.

The codec noticeably changes the rendering:

• SBC : audible compression on percussion attacks, tightened soundstage
• aptX Adaptive : good compromise, contained latency, preserved dynamics
• LDAC 990 kbps : better resolution of high harmonics, slight digital noise perceptible in quiet
• aptX Lossless : rendering closest to the source file on compatible DAP, difference mainly audible on closed headphones

On calibrated pink noise, the measured overall attenuation reaches 24 dB, a respectable result without reaching the level of the best over-ear headphones. The detail by band reveals a classic profile of in-ear ANC: 18 dB between 100 and 500 Hz (subway rumble, airplane engine), but only 9 dB above 2 kHz, where voices and clicks remain partially audible.

The adaptive mode correctly detects transitions between calm and noisy environments, with a recalibration time measured around 1.2 seconds, which remains imperceptible in normal use. The behavior on TGV Paris-Rennes confirms good management of low-frequency rolling noise, less convincing on station sound announcements.

Activating ANC slightly modifies the signature: a bass shelf perceived as an increase of about 1 dB, probably linked to the compensation algorithm, accompanied by a slight electronic hiss audible in a silent environment (closed office, bedroom). This background noise remains inaudible as soon as the ambient level exceeds 40 dB SPL, which covers the majority of real uses in transport or open-space.

In real-world conditions (LDAC 990 kbps, ANC enabled, volume at 75 %), the editorial team measures an autonomy of 4 h 10, close to the manufacturer's announcement of 4 h 30 but without margin. Without noise reduction and in aptX Adaptive, autonomy rises to 6 h 40, also slightly below the announced 7 h.

Quick charge allows recovering approximately 1 h of listening for 10 minutes on mains, which limits the damage in occasional nomadic use. With the full case (three full charge cycles), total autonomy reaches approximately 16 h 30 ANC enabled, insufficient to cover a long-haul flight Paris-Tokyo without intermediate recharging of the case itself.

The 6 microphones and beamforming processing deliver clear voice capture in calm conditions, but behavior varies strongly depending on the tested environment :

• Street with traffic : intelligible voice, slight chopping on engine noise peaks, correct suppression of continuous background noise
• Metro car : noticeable degradation, the interlocutor reports a more muffled voice as soon as ambient noise exceeds 70 dB SPL
• Open-space : good compromise, suppression of third-party conversations works without clipping the main voice
• Coastal walk with Atlantic wind : capture degraded by wind beyond 15 km/h, whistling-type artifacts in the lows

Software processing remains correct without being exceptional : the argument of 6 microphones does not translate into markedly superior intelligibility compared with the best 2-microphone models when well calibrated, such as the AirPods Pro 2.

Multipoint works correctly between a work PC and a smartphone, with an automatic switch during an incoming call measured at approximately 2,8 seconds, a reasonable but perceptible delay in videoconferencing. In gaming, latency measured in aptX Adaptive low-latency mode drops to 65 ms, sufficient for most titles outside demanding competitive play.

The Edifier ConneX application offers :

• a 10-band parametric equalizer, with presets by musical genre
• fine adjustment of ANC intensity (three levels) and transparency mode
• smooth firmware update, tested without failure over two cycles
• precise autonomy display per earbud and per case

Ergonomics remain correct, with reactivity sometimes lagging 1 to 2 seconds when changing EQ preset, without consequence on overall connection stability.

This comparison confirms a clear positioning: the STAX Spirit S10 wins on transient restitution and the range of Hi-Res codecs, but concedes ground on ANC, battery life and long-term comfort. For strictly audiophile use in short sessions (train, office, urban commutes), the planar argument justifies the compromise.

For versatile use including long-haul flights or full days without recharging, the Sony WF-1000XM5 or the Technics EAH-AZ80 remain more rational choices despite a less specific sound signature.

At 299 euros at launch, the STAX Spirit S10 positions itself at the top of the premium segment, without benefiting from the versatility expected at this price level. Occasional drops to 259 euros have been observed during sales operations early 2026, which significantly improves the value for money without changing the usage profile.

The consistent buyer profile stands out clearly:

• audiophile already equipped with a Hi-Res source (LDAC smartphone or DAP compatible with aptX Lossless)
• user favoring short and focused listening sessions rather than full days without recharging
• curious about planar magnetic technology in in-ear format, rare under 400 euros

Users looking for a versatile TWS for sports, frequent calls and long battery life will find a better compromise with Sony or Technics.