Friends who are concerned about audio products should be familiar with JBL. As a well-known audio brand under Harman Kardon, its products cover various types of speakers and headphones. Recently, JBL launched an iterative upgrade of the LIVE series of over-ear wireless headphones – JBL LIVE 660NC, which focuses on ANC adaptive active noise reduction and a new listening experience.
The appearance of JBL LIVE660NC continues the design style of the previous generation. It adopts a soft fabric with better air permeability, and the adjustable metal head beam fully fits the contour of the head, providing a comfortable wearing experience. The functional configuration uses a 40mm large-size unit to support JBL’s iconic sound effects. Upgrade ANC adaptive noise reduction, support intelligent ambient sound perception and free conversation mode, comprehensive stereo call technology to improve call quality, and have a long battery life of 50 hours.
52audio also teardown the JBL LIVE PRO+, JBL TUNE 225, JBL FREE II, JBL Free, JBL CHARGE 4 and JBL FLIP5 bluetooth speakers. Let’s take a look at the appearance design and internal structure configuration of this product.
01/ JBL LIVE 660NC Headphones Teardown
After unpacking, we learned about the overall appearance design of this product, and roughly understood the internal structure location through the interface. Next, enter the disassembly section to see the detailed structure configuration information.
First disassemble the left headphone and remove the earmuffs.
The earmuffs are fixed by a buckle, and the dust-proof mesh cloth is fixed on the earmuffs.
The sound cavity cover of the left headphone is fixed by multiple screws and is engraved with the L logo, which is convenient for distinguishing during production and assembly.
A noise-reducing microphone for picking up the noise inside the ear canal is arranged in the middle of the cover, the sound receiving hole is facing the speaker, and the back is closed structure.
Remove the back of the headphone and use a snap-fastened decorative ring.
The back cover fixing screws are hidden under the decorative ring.
Remove the screws to open the cavity, and the battery unit is fixed inside the cover, which is connected to the PCB board through wires and sockets.
The inner structure of the cover plate, the battery is fixed in the groove.
Below the battery is a circular touchpad.
The touch detection IC of the silk screen 01DP.
Replenishable lithium-ion battery pack model: 683331, rated capacity: 750mAh/2.775Wh, voltage 3.7V, charging limit voltage: 4.2V, manufacturer: Springpower Technology (Shenzhen) Co., Ltd..
The silk-screen information on the internal battery cell is consistent with the external label.
The battery is equipped with a circuit protection board, which is responsible for protection functions such as overcharge, overdischarge, overcurrent, and temperature detection.
The PCB board in the left headphone is fixed by screws, and dozens of wires are welded on the edge to connect the speaker and the right headphone.
The head beam and the ear shell are connected to the shaft structure.
The left headphone PCB board circuit is the power input board, used for input protection and battery charging, without too many other devices.
Remove the PCB board and the internal structure of the cavity.
Indicator light guide.
Silk-screened 1AM transistor.
LED indicator for feedback of charging status.
The charging IC of the silk screen EV4D.
YongFuKang CS5801T overvoltage and overcurrent protection IC, supports front-end protection of lithium battery charger, the maximum input withstand voltage is 30V, the current limit is programmable, and the maximum output current is 1.5A.
SGMICRO SGM3157 single-pole bidirectional single-pole double-throw (SPDT) CMOS analog switch, operating from a single power supply of 1.8V to 5.5V, with high bandwidth (300MHz) and low on-resistance (4.5Ω TYP), is aimed at audio switching target applications.
The triode of the silk screen MOY.
Open the sound cavity, you can see the second noise reduction microphone, used to pick up external environmental noise.
The electret microphone is fixed in the card slot and sealed with glue.
The front of the electret microphone is provided with a rubber sleeve on the outside, and the inside is protected by dustproof cotton to improve the sound reception performance.
On the back of the speaker unit, there is a damping paper around it for acoustic tuning.
After actual measurement, the speaker size is about 40mm, which is consistent with the official publicity.
Go to the disassembly part of the right headphone and remove the decorative ring.
Remove the screws one by one.
Inside the cover.
Conveniently under the cover is the main board unit.
Open the main board, and there is a cable via hole at the bottom to connect to the sound cavity.
The circuit on the front of the motherboard.
Add and subtract volume and pause/play function buttons on the motherboard.
Audio interface female seat.
Active noise reduction switch.
Two LED indicators are used to feedback the current mode of the headset.
X-Powers AC107 ADC converter is a dual-channel ADC chip with 103dB dynamic range, high performance and low power consumption. It is used for microphone analog-to-digital conversion and sent to the processor for processing.
CHIPSTAR TK0450D stereo headphone amplifier chip supports differential input.
The regulator tube of silk screen IO.
The regulator tube of silk screen 13.
Silkscreen 1553 IC.
Onboard bluetooth antenna.
Filter IC of silk screen DM.
Headphone bluetooth pairing indicator light guide.
+/-Volume button keycap structure.
The call microphone is fixed in the card slot and sealed by a large amount of glue.
Cut the shielding cover on the motherboard, and the main control chip is underneath.
BES BES2300YP bluetooth audio SoC, BES2300 has multiple versions with different suffixes and different configurations. 52audio has classified this in detail before. 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 bluetooth monitoring 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. BES2300 can output sound to headphones and home audio, and can also record from an external microphone.
According to 52audio, there are already true wireless headsets of Samsung, Xiaomi, OPPO, JBL, 1MORE, Honor, Baidu, OnePlus, Transsion, Realme, Anker and other brands that have adopted a large number of BES solutions.
Remove the ear cup of the right headphone.
The cavity is opened, the inner wire is connected to the main board via a hole, and a noise reduction microphone is set on the cavity wall to pick up external environmental noise.
A small crescent-shaped plate is arranged next to the speaker for capacitance wearing detection function.
Wear a small plate of the detection sensor, with a capacitance detection plate in the middle.
Capacitance detection IC with silk screen A2N5.
All components of JBL LIVE 660NC head-mounted bluetooth headphones.
The JBL LIVE 660NC head-mounted noise reduction headphones have a complete head beam structure in the appearance design and support all functions such as telescopic, rotating and folding. With soft and skin-friendly earmuffs, they are comfortable to wear without a chuck, and are more convenient to carry out. The fabric material used in the head beam also avoids the problem of skin peeling after long-term use of leather-like materials, and improves the service life.
In terms of internal structure configuration, 40mm driver units are used in the left and right headphones, and two electret microphones are built in for active noise reduction. The left headphone is also equipped with an additional call microphone. The battery and touchpad are located on the left headphone, using Springpower Technology 750mAh lithium-ion battery, YongFuKang CS5801T overvoltage and overcurrent protection IC is responsible for the front-end protection of the charger, and a SGMICRO SGM3157 single pole bidirectional single pole double throw (SPDT) CMOS simulation switch.
On the internal motherboard of the JBL LIVE 660NC right headphone, the BES BES2300YP bluetooth audio SoC is used, which integrates an adaptive active noise reduction solution, supports bluetooth 5.0, IBRT bluetooth monitoring technology and dual-mode bluetooth 4.2, supports the third-generation FWS full wireless stereo technology, dual microphones, etc. X-Powers AC107 dual-channel ADC chip, used for microphone analog-to-digital conversion, sent to the processor for processing, and Chipstar TK0450D stereo headphone amplifier, etc. The right headphone is also provided with a “crescent-shaped” capacitance detection plate and capacitance detection IC for wearing detection function.