Explosive TWS headset disassembly analysis, see how Xiaomi Air 2 SE is configured


The Xiaomi Air 2 SE true wireless headset is an entry-level Bluetooth headset currently on sale under the Xiaomi brand. In appearance, the charging case adopts a square folding opening and closing design. The headset is still the classic appearance of the Air series, with a handle-like semi-in-ear design for a stable and comfortable wearing experience.

In terms of functional configuration, a 14.2mm large-size composite diaphragm dynamic driver is used to support AAC audio codec. It adopts touch operation and supports wearing detection function. Use with Xiaomi mobile phones to support smart connection in the open box pop-up window to check the charging case and the remaining power of the headset; it also supports the noise reduction function of dual microphones. In terms of battery life, a single charge is 5 hours, and the overall battery life is 20 hours.

52audio previously disassembled the Xiaomi FlipBuds Pro noise-cancelling earphones, Xiaomi Air 2 Pro noise-cancelling earphones, Xiaomi Air 2S, Xiaomi Air 2, Redmi AirDots 3 Pro true wireless noise-cancelling earhones, Redmi AirDots 3, Redmi AirDots 2, Redmi AirDots true wireless bluetooth earphones, as well as Xiaomi Sound smart speakers, Xiaomi xiaoai portable speakers and other 16 bluetooth speaker products of Xiaomi, let’s take a look at the internal structure of this product.

| 1. Xiao Air 2SE ture wireless earphones unboxing

The packaging box still uses a blue and white background, the front shows the product appearance rendering, the Xiaomi brand LOGO, and the product name: Xiaomi True Wireless Bluetooth Headset Air 2 SE, four product features: open the box pop-up window, long-lasting battery life, call noise reduction, stable connection.

The back of the box is part of the product parameter information, including product model: TWSEJ04WM, speaker impedance: 32Ω, input: 5V-1A, wireless connection: bluetooth 5.0, charging time: about 1.5h, support codec: SBC/AAC, etc.

The items in the box include earphones, charging cables and product manuals.

USB-A to USB Type-C charging cable.

The charging case adopts a flat square box design similar to a “rice cooker”, with a chamfer on the front opening for easy opening, and an indicator light below.

On the back of the charging case is the Type-C charging interface.

The bottom silkscreen information of the charging case is Xiaomi True Wireless Bluetooth Headset Air 2 SE, product model: TWSEJ04WM, input: 5V⎓1A, output: 5V⎓0.2A, battery model: VDL682723, output: 3.8V, capacity: 410mAh. 1MORE Acoustic Technology Co., Ltd., made in China.

The overall appearance of the Mi Air2 SE true wireless headset.

The thimble for charging the headset is located in the cockpit of the headset handle.

The overall appearance of the Xiaomi Air 2 SE earphone adopts a handle-shaped semi-in-ear design, and the earphone handle is an elliptical cylindrical structure.

The noise-reduction microphone on the back of the earphone handle is equipped with a strip groove in the touch area, which is convenient for blind operation.

There is a hidden headphone indicator light below.

The inside of the earphone handle is a metal contact for charging the earphone.

The bottom of the earphone handle is a call microphone.

A circular pressure relief hole is arranged inside the earphone head.

An oval pressure relief hole is also provided on the side of the earphone.

The sound mouth of the earphone is protected by a metal dust-proof net to prevent foreign objects from entering the sound cavity.

After actual measurement, the weight of the Mi Air2 SE true wireless headset is about 47.2g.

A single headset weighs about 5.1g.

Use a portable power tester to perform a wired charging test on the Xiaomi Air 2SE true wireless headset, and the input power is about 1.23W.

| 2. Xiaomi Air 2 SE true wireless earphone teardown

Charging case teardown

Pry open the charging case cockpit and take out the internal components.

The charging case uses a spring to increase the damping feel at the rotating shaft of the open cover.

The internal components fit the cockpit structure of the charging case, making full use of the internal space.

Remove the screws and take off the main components in the charging case.

Three magnets are provided at the bottom of the cockpit to absorb the lid and earphones.

The main circuit in the charging case.

Rechargeable lithium ion battery model: 682723, rated voltage: 3.8V, rated capacity: 410mAh/1.558Wh, charging limit voltage: 4.35V, from VDL Electronics.

The circuit on the front of the motherboard.

The circuit on the back of the motherboard.

The Hall element of silk screen 1A1N 1ZA9 notifies the headset to connect/disconnect with the paired device by sensing the magnetic field change (Hall effect) when the charging case cover is opened/closed.

Pogo pin connector for charging the earphones.

SinhMicro SS881A is an AD-type Flash microcontroller with integrated charge and discharge management, integrated power management unit and charging management unit, and provides real-time configurable charging voltage and current settings with full software. SS881X is one of the products of SinhMicro POWR MCU series. The chip integrates rich power management functions to meet the overall requirements of the product for charging flexibility and safety.

In response to the intelligent trend of TWS products, the SS881X series has achieved two-way communication with major mainstream headset platforms, and the products can be iterated quickly. And the chip integrates a dedicated interface to support USB upgrades and production testing.

According to 52audio, many TWS headset charging cases including Razer, Edifier, Redmi, OPPO, 1MORE, ZMI, realme, FIIL, Anker, Lenovo, Astrid, Nubia and other brands have adopted a large number of charging cases. SinhMicro’s solution.

The boost IC of the silk screen 2501BA boosts the battery in the charging case to charge the earphones.

Xysemi XB5352G integrated lithium battery protection IC, responsible for the built-in battery overcharge, overdischarge, overcurrent and load short circuit protection functions.

Xysemi XB5352G detailed information.

Under the black shading tape is a white LED indicator.

A close-up of the Type-C charging interface female seat, through-hole welding.

Earphone teardown

Pry open the earphone along the clamping line, only the speaker unit is set inside.

A close-up of the front of the speaker, using a composite diaphragm.

According to the actual measurement of Woai Audio Network, the size of the speaker unit is about 14.2mm, which is consistent with the official publicity.

A large-area capacitive in-ear detection sensor is affixed to the back cavity wall, and the speaker wire and cable vias are sealed with glue.

Heat the earphone handle clamping wire and pry open the earphone handle back plate.

A strip touch detection sensor is arranged on the inside of the back plate, and two black double-sided adhesives are used to fix the noise-reducing microphone dust-proof net and the indicator light to prevent light leakage.

The main board unit in the earphone handle, and the battery unit under the main board.

A close-up of the LED indicator and a black sponge around it to prevent light leakage.

Onboard bluetooth antenna.

Silk screen XQC IC.

BES BES2300 bluetooth Audio SoC is a fully integrated adaptive active noise reduction solution that supports bluetooth 5.0, IBRT intelligent forwarding technology and dual-mode bluetooth 4.2. It also supports the third-generation TWS full wireless stereo technology, dual microphones, etc.

BES2300 also supports external sensor devices such as heart rate sensors and acceleration sensors and eMMC flash memory, which can achieve the purpose of playing music on external storage devices. BES2300 can output sound to headphones and home audio, and can also record from an external microphone.

According to 52audio, there are already a large number of true wireless headsets from Samsung, Xiaomi, OPPO, JBL, 1MORE, Honor, Baidu, OnePlus, Realme, Anker and other brands that have adopted the BES solution.

Laser carving 26.000 crystal oscillator provides the clock for the bluetooth chip.

CHIPSEA Chipsea Technology CSS21P10 single-chip microcomputer, communicates with the charging case power supply signal, and realizes the control of the headset by opening the cover.

SpaceTouch SPT-502ND in-ear detection + touch detection chip, supports earphone capacitance in-ear wearing detection and touch operation, and adopts DFN-8L package.

The SPT500 series is a dedicated chip for in-ear detection, touch detection and pressure sensing developed by SpaceTouch for TWS headphones. It has ultra-high sensitivity, ultra-low power consumption, wide temperature adaptation and a unique anti-sweat processing mechanism. High-sensitivity capacitive in-ear detection can achieve light detection performance; touch detection function can achieve multiple functions such as single click, double click, multi-click, sliding, etc., to meet the needs of touch interaction applications of various bluetooth headsets; wide temperature adaptation and unique sweat resistance The mechanism can be well adapted to the accurate wearing detection of extreme scenes such as large environmental temperature differences and running.

The outside of the microphone is covered by a rubber cover to improve the sound reception performance.

Laser carving R114 A72D MEMS microphone is used for call noise reduction function.

The IC of the silk screen C2A1, the right side of the microphone is the capacitive in-ear detection cable, which is soldered on the circuit board.

The circuit on the back of the motherboard, the bottom call pickup microphone is protected by a blue protective cover, the battery is placed in the space between the back of the headset motherboard and the shell, the touch cable on the panel is also welded to the back of the motherboard, and the top is the battery and speaker connection, welded connect.

The MEMS microphone and the top call noise reduction microphone are of the same specification.

The magnet in the earphone handle is used to absorb the charging case.

Inside the earphone is a strip-shaped soft pack battery, model AEC350627, capacity: 48mAh/0.182Wh, rated voltage 3.8V, charging limit voltage 4.35V. From AEC.

Xiaomi Air 2 SE

All components of Xiaomi Air 2SE true wireless earphones.

| 3. Summary

Xiaomi Air 2 SE true wireless earphones continue the Air series in appearance design, and the overall appearance of the pure white body is clean and simple. The handle-shaped semi-in-ear earphones have a built-in battery set in the earphone handle, making the earphones relatively small in size and improving the comfort of wearing. But it also makes the earphone handle relatively thick, which makes it more prominent when worn.

In terms of internal circuits, the charging case uses Type-C interface input power, built-in lithium-ion soft-pack battery capacity 410mAh, Xysemi XB5352G integrated lithium battery protection IC, responsible for battery overcharge, overdischarge, overcurrent and short circuit protection functions; charging compartment The main control chip is Sinhmicro SS881A AD Flash MCU, which integrates power management unit and charging management unit, and provides real-time configurable charging voltage and current settings with full software.

The Xiaomi Air 2 SE headset part uses a 14.2mm large-size dynamic driver with a built-in 48mAh capacity strip soft pack battery; on the motherboard, the main control chip is BES BES2300 bluetooth audio SoC, supports bluetooth 5.0, and is equipped with two MEMS microphones on the motherboard. Dual microphone call noise reduction function; CHIPSEA CSS21P10 microcontroller is also used to communicate with the charging case voltage signal to control the headset by opening the cover; and SpaceTouch SPT-502ND in-ear detection + touch detection chip for in-ear detection and touch operation function.

Source: 52audio


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