Some time ago, BOSE officially launched its new generation of flagship TWS noise cancellation earbuds – Bose QuietComfort Earbuds II. The appearance adopts a new solution, the new Fit Kit eartips set design, with lighter and smaller earbuds, provides comfortable and stable wear all day long.
In terms of functional configuration, it supports Bluetooth 5.3, and the noise cancellation capability has been upgraded again. The specially customized independent noise cancellation chip is matched with the Bose noise cancellation algorithm to eliminate noise more accurately. The new CustomTune smart in-ear sound field adjustment technology can optimize the in-ear sound field in real time according to the structure of the ear canal. Combined with the ActiveSensse noise dynamic sensing technology, the transparent mode is more natural.
In other respects, the Bose QuietComfort Earbuds II are equipped with 8 microphone units for precise sound pickup and two noise cancellation microphones, bringing clearer and more natural voice calls. In terms of interaction, it supports three modes: click, long press and slide, which can easily control various functions. In terms of battery life, wireless charging has been cancelled, and the charging speed has been improved, and the earbuds can be fully charged in 1 hour. A single battery life is about 6 hours, and the comprehensive battery life with the charging case is about 24 hours.
52audio teardown Bose audio products include: Bose QuietComfort Earbuds, Bose Sport Earbuds, BOSE QuietComfort 45, Bose SOUNDSPORT FREE, Bose NC700, Bose QuietComfort 35 II and Bose smart audio glasses. Let’s take a look at the detailed teardown report of this product.
01/ Bose QuietComfort Earbuds II charging case teardown
Pry off the charging case cover and take out the cockpit.
The cable for charging the earbuds are fixed on the cockpit, and then connected to the motherboard through the ZIF connector and the cable.
The circuit on the cable.
Metal dome for charging/communicating earbuds.
The charging case indicator is used to feedback bluetooth pairing and remaining battery status.
Silkscreen 20U Hall element is used to sense the magnetic field change when the charging case is opened and closed. Notify the charging case control chip, and then inform the earbuds to connect/disconnect from the paired device, so as to realize the function of open the box and pair devices automatically.
The internal structure of the cavity, the main board and the battery unit are fixed on the bottom through the bracket.
The structure on one side of the bracket fixes the battery unit.
The structure on the other side of the bracket, the motherboard is fixed by screws.
A protection board is connected to the battery, and the protection board is connected to the main board through three wires.
The charging case uses a cylindrical lithium-ion battery, model: NTA3663, nominal voltage: 3.8V, rated capacity: 1100mAh/4.18Wh, charging limit voltage: 4.3V.
The battery protection board circuit, the upper line is the thermistor used to monitor the battery temperature.
There are no components on the back of the battery board guard.
Screen printing ZE’s lithium battery protection MOS, and below it is the battery protection IC.
The circuit on one side of the charging case motherboard.
The circuit on the other side of the charging case motherboard.
ST STM32L452RE microcontrollers, STM32L452xx devices are ultra-low-power microcontrollers based on high-performance Arm Cortex-M4 32-bit RISC cores, operating at frequencies up to 80MHz. The Cortex-M4 core features floating-point unit (FPU) single-precision, supporting all Arm single-precision data processing instructions and data types. It also implements a full set of DSP instructions and a memory protection unit (MPU) for enhanced application security.
Silkscreen 4L205 memory IC.
A dual op amp from Texas Instruments, silk screen 1GMH, the actual model is TLV9002.
Silkscreen KI’s resettable fuse.
Four screen-printed 2D0 ICs.
An electronic fuse chip from Texas Instruments, silk screen SKB, the actual model is TPS25200, used for overcurrent protection.
The step-down IC of silk screen 6EG is used to supply power to the MCU chip inside the charging case.
Silkscreen K64 J2 IC.
Silkscreen 8H IC.
TI BQ25618 charging IC integrates switching charging, synchronous boost converter and voltage protection functions. Supports 22V withstand voltage and reduces battery leakage to 6uA in shipping mode, for charging built-in lithium batteries and charging earphones.
Screen-printed OH NB’s boost IC for boosting the charging case battery to charge earbuds.
Bluetooth pairing function button on the motherboard.
Type-C charging socket, laser engraving model 220318.
Connect the ZIF connector of the charging cable for the earbuds.
02/ Bose QuietComfort Earbuds II earphones teardown
Enter the earbuds teardown section and disassemble the cavity along the parting line.
The internal structure of the rear cavity is provided with a mainboard unit.
The steel shell button battery in the front cavity is fixed on the frame and is isolated from the front cavity.
The front cavity cover is designed with an inverted tube, which is connected to the external tuning hole of the earbud to enhance the low-frequency quantity sense of the earbud.
Take out the speaker, the internal structure of the sound tube. The flex cable connects to the feedback microphone and the in-ear sensor.
The circuit inside the front cavity is wired.
The front of the earbud speaker is equipped with a layer of fiber diaphragm to improve the bass effect.
After actual measurement, the speaker size is about 8mm.
The optical in-ear detection sensor is used to automatically resume playback when wearing the earbud, and automatically pause playback when the earbud is removed.
Laser carving 216 VEEPV’s in-ear microphone picks up sound from the inside of the ear canal for noise cancellation and automatic optimization of the in-ear sound field.
The MEMS microphone of laser engraving QR code is used for voice pickup for calls and noise cancellation functions.
The front cavity cable is connected to the BTB connector male socket of the motherboard.
The earbud uses a steel shell button battery, model: M1454S2, voltage: 3.85V, capacity: 0.404Wh, from MIC-POWER.
Battery negative electrode, laser engraving QR code information.
Remove the back cover of the headset stem, there is also a cover below, and the touch detection electrodes and the LDS laser antenna are printed.
Remove the cover plate, the main board unit structure inside the cavity.
The inside of the cover is connected to the motherboard via contacts.
Take out the motherboard, and there is a small power input board below, which is connected to the motherboard through a cable.
Connect the feedforward noise cancellation microphone to the end of the cable.
Take out the cable inside the rear cavity, and connect the circuit on one side of the cable.
The circuit on the other side of the cable.
Call pickup microphone with laser engraving QR code.
Another pickup microphone. A single earbud is equipped with four MEMS microphones to provide precise sound pickup.
Inside the headset stem are the earbud charging/communication metal connector and the call microphone hole.
The circuit on one side of the earbud motherboard.
The circuit on the other side of the earbud motherboard.
The Qualcomm QCC5171 bluetooth audio SoC is part of Qualcomm’s latest S5 (QCC517x) audio platform. The Qualcomm S5 audio platform is optimized for AI, providing ultra-low-power performance with twice the computing power compared to the previous generation. The Qualcomm S5 audio platform is built on a Bluetooth 5.3 dual-mode radio, enabling a range of exciting new LE audio experiences. The Qualcomm S5 audio platform also supports Qualcomm Snapdragon Sound technology and supports the newly added 16-bit 44.1kHz CD-level lossless bluetooth sound quality.
Qualcomm Snapdragon Sound technology also supports 24bit/96KHz high-resolution audio, Qualcomm aptX audio encoding, including aptX™ Adaptive technology. Support aptX™ Voice to optimize call voice and 8th generation Qualcomm cVc echo cancellation and noise suppression technology. Integrated Qualcomm adaptive active noise cancellation, including feedforward, feedback, mixing and adaptive, supports third-party innovation through Qualcomm extensions.
According to 52audio, there are many TWS earbuds, over-ear headphones, neckband bluetooth earphones, smart speakers, smart audio glasses and other audio products that use Qualcomm bluetooth audio SoC.
Silkscreen 73GM IC.
Silkscreen 71215 BCBZ noise cancellation IC, from ADI, customized by BOSE. Bose QuietComfort Earbuds true wireless noise cancellation earphones and BOSE QuietComfort 45 over-ear noise cancellation headphones also use this chip.
The crystal oscillator that provides the clock for the noise cancellation IC.
ST STM32L4A6VG Ultra Low Power 80 Mhz Arm Cortex-M4 MCU with FPU. Features 1MB Flash memory, USB OTG, LCD, AES-256 and DFSDM for sound tuning and optimization.
Silkscreen C 1HB IC.
Cypress PSoC 4000S series MCU for touch detection function.
Silkscreen Q128J memory for storing firmware information.
Silkscreen 129 2P8 IC.
Silkscreen 2EC IC.
The 32.000MHz crystal oscillator provides the clock for the bluetooth chip.
Silkscreen 12 2200H IC.
Silkscreen 6ED step-down IC.
Connect the BTB connector female socket of the power input small board cable.
The BTB connector female socket connected to the inner cable of the front cavity, the contacts are arranged alternately, and the density is increased.
Connect the metal dome of the touch detection electrode.
All components of BOSE QuietComfort Earbuds II true wireless noise cancellation earphones.
The Bose QuietComfort Earbuds II have a completely new design in terms of appearance. The charging case is shaped like a “shield” vertical structure, with a matte texture and a comfortable grip. The earbuds use a handle-shaped in-ear design, but it is different from the current mainstream design. The headset stem is wider and integrated with the earbud head structure, making it highly recognizable. Newly designed Fit Kit eartips set, soft silicone material, eartips separated from the stabilizing ring. Equipped with three sizes to match freely, providing a personalized and comfortable wearing experience.
In terms of internal circuits, the charging case uses the Type-C interface input power supply, built-in 1000mAh large-capacity cylindrical battery, and is equipped with a circuit protection board for charging and discharging protection. TI BQ25618 charging IC charges the built-in lithium battery and earbuds, supports 22V withstand voltage, and supports shipping mode. ST STM32L452RE microcontroller with built-in Arm Cortex-M4 32-bit RISC core for charging case control.
In terms of the main internal configuration of earbuds, it is equipped with an 8mm dynamic driver. A single earbud has 4 built-in MEMS microphone units for precise sound pickup. The earbud main control chip adopts Qualcomm QCC5171 bluetooth audio SoC, which has lower power consumption and stronger computing power. Supports Bluetooth 5.3 and Snapdragon Sound technology to provide earbuds with high-definition music, clear calls and low latency. It is also equipped with ADI noise cancellation IC to improve noise cancellation performance.
In other respects, the earbud is also equipped with ST STM32L4A6VG ultra-low power consumption 80 Mhz Arm Cortex-M4 MCU with FPU. The Cypress PSoC 4000S series MCU is responsible for the touch detection function. The earbud has a built-in MIC-POWER steel shell button battery with a capacity of 0.404Wh, which provides energy support for various functional applications of the earbud.