Soundcore is an audio brand under Anker. In 2014, Anker released the first Bluetooth speaker and then launched the earphones product line. With the rapid development of TWS true wireless earphones, Soundcore seized the opportunities of the times with its high-quality products and became the first Enter the top 10 Chinese headphone brands in the global TWS headphone sales.
Today I’m going to disassemble Soundcore’s newest TWS true wireless noise-cancelling earphones——Soundcore Liberty Air 2 Pro. In terms of appearance, this product inherits the family-style design style, and the charging case uses the same as Liberty 2 Pro. The sliding cover design supports the connection when the cover is opened, and the volume is more compact and square; the earphone adopts a handle ear design similar to Liberty Air 2, but the shell is more rounded, especially the structure of the ear.
In terms of configuration, Soundcore Liberty Air 2 Pro features 5-in-1 multi-scene double-feed noise reduction, supporting three noise reduction scenarios: commuting, indoor and outdoor, and two transparent modes: full transparency and vocal mode; the speaker uses 10 layers of high hardness Coating and PureNote™ technology, combined with HearID 2.0 technology that customizes sound quality based on the hearing curve of the human ear, has been recommended by 10 Grammy award-winning musicians; there are three microphones in a single earphones for call noise reduction; charging case supports wireless Charging, the single battery life of the earphones is about 7 hours, and the overall battery life can reach 26 hours. 52audio has evaluated the Soundcore Liberty Air 2 Pro and analyzed detailed laboratory test data. Interested friends can click to view it.
Soundcore true wireless earphones that have been used by 52audio include: Soundcore Life Dot 2 true wireless bluetooth earphones, Soundcore Liberty 2 Pro true wireless bluetooth earphones, Soundcore Liberty Air 2 true wireless bluetooth sports earphones, Soundcore Spirit Spirit True wireless bluetooth sports earphones, Soundcore Spirit Spirit earphones.
| 2. Soundcore Liberty Air 2 Pro charging case teardown
After unpacking the box, we have a comprehensive understanding of the appearance of the Soundcore Liberty Air 2 Pro true wireless noise-cancelling headphones. The charging case is more interesting with a sliding lid. The appearance design of the headphones and charging case uses a lot of circles. Angle, improve comfort. Next, we will enter the dismantling process to take a look at its internal structure design and chip information.
Pry open the charging cockpit, the shell is fixed with multiple buckles and two plastic posts.
The module where the Pogo Pin is located and the indicator module are connected by three enameled wires, and the solder joints are reinforced with glue.
The indicator module is connected to the main board circuit through the FPC and the connector.
Soundcore Liberty Air 2 Pro charging case internal structure.
Three LED indicators are used to display the battery power of the charging case.
The structure of the sliding position of the box cover.
The cable where the Pogo Pin is located is fixed by hot melt and glue on the shell.
There are no components on the other side of the wire solder joint.
The internal structure of the charging case, the cylindrical lithium battery is located on one side, and the main board is an inverted “T” shape, so that the design can effectively use the space.
The light guide of the LED indicator has black foam on the outer ring to avoid light leakage.
The PCB of the matched button is connected to the main board through two wires.
The PCB of the mating button is also fixed by the shell hot melt and glue.
The wireless charging receiving coil is fixed on the shell at the bottom of the charging case with glue, and is covered with a layer of magnetic isolation sticker.
Wireless charging receiving coil, multiple enameled wires are wound in parallel.
One side of the motherboard circuit.
The other side of the motherboard circuit.
The Hall element of silk screen AT0m. Charging case The magnetic field changes when the lid is opened and closed will be sensed by the Hall element, and the charging case will be notified that the MCU and earphones are paired or disconnected with the connected device.
LPS LP5305 is an overvoltage and overcurrent protection chip that supports 26V withstand voltage. It supports charger front-end protection, monitors battery voltage, prevents input overvoltage from damaging the internal components of the earphones charging case, and also prevents battery overcharging. According to 52audio, audio products from brands such as Xiaomi, OPPO, Huawei, Lenovo, Motorola, Realme, Edifier, QCY, JLab, Skullcandy, Boltune and other brands have adopted a large number of LPS power management chips.
The single-chip microcomputer of the silk screen EC04M332 is used for charging case control.
The SY8801 chip designed by TPS specifically for the TWS earphones charging compartment is designed to ensure safe and highly reliable performance (support 28V input withstand voltage, built-in full-featured charging and discharging overvoltage, overcurrent, overtemperature, short circuit protection and other functions) , It also integrates I2C communication function and internal communication isolation function. Through the I2C interface, the system’s MCU can read and configure the internal functions of the power supply and the parameters of battery charging and discharging management, and easily realize such as NTC protection, segmented adjustment of battery current, TWS earphone in warehouse, warehouse out detection, and automatic power output. And other functions.
The integrated internal communication isolation module of TPS SY8801 greatly optimizes the functional design of the intelligent TWS charging compartment, without complicated peripheral circuits, and the MCU can be realized by connecting and controlling the SY8801. Not only can it realize the function of charging the earphones, but also the data communication transmission can be carried out through the power source POGO PIN connected with the earphones, which includes functions such as uploading the power of the charging compartment, clearing the pairing of the earphones in the charging compartment, restoring factory settings, and upgrading the earphone software.
According to 52audio, the TPS power management chip has been adopted by many well-known brands such as OPPO, Xiaomi, Baidu, 1MORE, 233621, Transsion, and OnePlus.
ChipsVision CV8013N wireless charging and receiving SoC, with high integration, high efficiency, low heat, rated power 5W, compatible with Qi V1.2.4 standard, support OCP, OVP, OTP and FOD functions, suitable for TWS earphones charging case, smart watches , Mobile power, smart phones and other equipment.
According to 52audio, there are already true wireless earphones charging cases of Anker, JBL, ROWCING, Dacom and other brands that use ChipsVision wireless charging and receiving SoC.
Five MLCC capacitors are connected in parallel for filtering.
The battery is connected to the motherboard through three wires and connectors.
The supplier of the cylindrical soft pack battery comes from VDL, model 11425PN2, diameter 11mm, length 42.5mm, battery capacity 500mAh, energy 1.85Wh, and rated voltage 3.7V.
A close-up of the battery protection circuit, with an integrated protection IC on it, responsible for battery overcharge, overdischarge and overcurrent protection functions.
| 2. Soundcore Liberty Air 2 Pro earbuds teardown
Let’s continue to disassemble the earphones part of Soundcore Liberty Air 2 Pro. The earphone adopts a handle-in-ear design, and the ear-in shell and the earphone handle shell use different colors to enrich the look and feel.
On the top of the earphone handle, there is an opening for a noise reduction microphone and an LED indicator.
On the outside of the earphone handle, the side of the shell has a transition treatment, which looks more natural; the Soundcore Logo on the top of the earphone handle is a touch area, which supports two interactive methods of double-click and long-press; the Soundcore brand name below uses a bright surface treatment , Contrast and increase texture.
The microphone pickup hole at the bottom of the earphone handle has a dust-proof net inside.
The charging contacts and magnet area on the inside of the earphone handle are slightly concave, and there is an L/R logo on the bottom.
Pressure relief/tuning hole near the mouthpiece.
The metal protective cover at the sound mouth is designed as a petal shape, which is more beautiful; there is a dust-proof net inside to prevent foreign objects from entering.
Disassemble the earphone along the parting line, the battery can be seen in the sound cavity shell.
The internal layout after removing the headphone handle cover.
Inside the earphone handle cover, the bluetooth antenna occupies a lot of space, and is connected to the Pogo Pin on the motherboard through two metal contacts; the top small plate is used for sound pickup and touch operation.
Laser carving F061 0390’s MEMS silicon microphone is used to collect ambient sound and assist in active noise reduction and call noise reduction. This PCB is connected to the motherboard through a 6Pin BTB connector and FPC.
Silkscreen 233DS is a touch key detection IC, from tontek, belonging to the TTP223N series.
A large amount of glue is used to seal the joints of the shell to improve the airtightness and waterproof ability.
The internal circuit of the sound cavity is also connected to the motherboard through the FPC and BTB connectors.
Near the bottom of the earphone handle, there is a rubber protective cover on the motherboard.
Disconnect the connector and continue disassembly.
The in-ear detection function of the earphones uses a capacitive sensing solution. The above picture shows the location of the in-ear detection FPC, which has a large area.
The internal structure of the Soundcore Liberty Air 2 Pro earphones.
Pogo Pin’s openings and magnets for attaching the charging cockpit.
The pickup hole of the microphone on the top of the earphones and the light guide of the indicator light.
The circuit on the motherboard side and the size comparison with CNY coin.
The circuit on the other side of the motherboard, below the QR code sticker is the bluetooth master chip.
The main control chip of Soundcore Liberty Air 2 Pro is BES BES2300YP. BES2300 has multiple versions and different configurations with different suffixes. 52audio previously classified this in detail. Both BES2300Y/YP models support active noise reduction.
The BES2300 series is a fully integrated adaptive active noise reduction solution that supports bluetooth 5.0, IBRT low-frequency forwarding technology and dual-mode bluetooth 4.2. It also supports the third generation of FWS full wireless stereo technology, dual microphones, etc., using 28nm HKMG CMOS process, BGA package . BES2300 supports high-performance adaptive active noise reduction technology, which allows high-end active noise reduction headphones to use a fully integrated chip to achieve high sound quality and active noise reduction.
In addition, BES2300 also supports external heart rate sensors, acceleration sensors and other external sensor devices 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, a large number of true wireless earphones from brands such as Huawei, Samsung, Xiaomi, OPPO, JBL, 1MORE, Honor, Baidu, and OnePlus have adopted BES solutions.
Two gold-plated Pogo Pins connected to the bluetooth antenna.
Silk screen XdA IC.
A battery protection IC.
The Pogo Pin, which charges the earphones battery, has a rubber ring outside for waterproofing.
The IC of the silk screen 09006.
The bluetooth filter of silk screen 73.
Two LED indicators.
There is a protective cover at the pickup hole of the call microphone.
Laser carving F001 0546’s MEMS silicon microphone is used to pick up the sound in the direction of the human mouth during a call.
There is a magnetic barrier sticker between the battery and the motherboard.
After peeling off the magnetic isolation sticker, there are some components on the FPC, and the left and right sides are the solder joints of the battery’s positive and negative poles.
The regulator IC of silk screen MGJ.
Azoteq IQS269A ProxFusion® IC is an 8-channel capacitive proximity and touch controller with excellent class sensitivity, signal-to-noise ratio and power consumption. It is used here for the in-ear detection function of the earphones.
Azoteq IQS269A also provides hybrid sensing capabilities such as Hall effect and capacitive sensing. Other functions include automatic tuning of sensory electrodes and differential offset compensation. It can be applied to TWS earphones, touch controllers, wear detection, low-power wake-up, Hall detection, multi-slide/key design and other products.
According to 52audio, audio products of well-known brands such as 233621, Bose, Buttons, Cleer, Huawei, Microsoft, and RHA have adopted Azoteq sensors.
Azoteq IQS269A ProxFusion® details.
1254 button type soft pack battery, diameter 12mm, thickness 5.4mm, rated voltage 3.7V, energy 0.204Wh.
The structure in the sound cavity after removing the battery.
The black plastic part that holds the battery.
The speaker unit is connected to the FPC through a wire.
The speaker unit is fixed with black glue.
Take out the speaker unit and find that there is a plastic bracket underneath, inside is the feed-back microphone of the earphones.
The shell structure after removing the components.
The dust-proof net inside the mouthpiece.
The blue glue fixes and adsorbs the magnet of the charging case, and there is an L/R mark on the shell.
There is another piece of FPC for ear detection function on one side of the support structure.
Laser carving F040 0325’s MEMS silicon microphone picks up the sound in the ear canal for active noise reduction and call noise reduction.
The other side of the stent structure.
The loudspeaker unit is officially advertised with a 10-layer high-hardness coating, which can reduce the split vibration of the diaphragm, reduce distortion, and restore pure sound quality.
The tuning hole on the side of the speaker unit.
The size of the speaker unit is approximately 11mm.
Soundcore Liberty Air 2 Pro earbuds all components.
Soundcore Liberty Air 2 Pro true wireless noise-cancelling headphones are distinctive in appearance. The charging case adopts a horizontal sliding switch design, which has a certain sense of damping, and supports the opening and connecting function, which is convenient to use; the earphone adopts a handle-in-ear design. Taking into account the functions of active noise reduction and call noise reduction, the collision of the two colors and craftsmanship also increases the quality of the product. Soundcore Liberty Air 2 Pro’s main 5-in-1 multi-scene double-fed noise reduction further subdivides the active noise reduction and ambient sound modes, which are considered more carefully.
In terms of internal circuits, Soundcore Liberty Air 2 Pro uses USB Type-C interface input power, LPS LP5305 supports 26V withstand voltage, is responsible for input protection and prevents battery overcharging; TPS SY8801 chip is responsible for battery charging and discharging, integrated I2C communication function and internal Communication isolation function can help MCU realize various charging case functions; charging case supports wireless charging function, wireless charging receiver chip is ChipsVision CV8013N, rated power 5W, supports Qi V1.2.4 standard; built-in cylindrical soft pack battery comes from VDL, capacity 500mAh.
In the earphone part, the opening position of the Soundcore Liberty Air 2 Pro is ingenious to ensure a beautiful appearance; there are better waterproof and sweat-proof measures inside; a bracket is used to fix the speaker unit and battery in the sound cavity to reduce resonance and affect the sound quality; one in the earphone The FPC connects in-ear detection foils, batteries, speaker units, and feed-back microphones in series. The use of BTB connectors can improve production efficiency; the overall structure design is better.
Soundcore Liberty Air 2 Pro adopts dual-feed ANC noise reduction technology, which has a feed-forward microphone and a feed-back microphone to pick up the sound. The bluetooth master chip and noise reduction chip is BES BES2300YP, and there is a microphone at the bottom of the earphones handle that can be directed during a call. Pick up the human voice, three microphones work together to achieve a better noise reduction effect; the earphones uses a capacitive touch solution and an in-ear detection solution, and the control chips are Tontek TTP223N and Azoteq IQS269A; the button-type soft pack battery has a capacity of approximately 55mAh; the size of the dynamic driver is about 11mm, and PureNote™ technology is used to reduce the split vibration of the diaphragm and reduce distortion.