On August 10th, Xiaomi’s “2021 Lei Jun Annual Lecture” was successfully held and a number of new products were launched at the same time. Among them, Xiaomi’s first high-end smart speaker – Xiaomi Sound was also officially released.
The Xiaomi Sound smart speaker is small in size, and its design is inspired by the record player. The appearance is cylindrical and the body is made of transparent material. The top touchpad is like a vinyl record on a turntable, and is designed with CD texture decoration, and there is also a ring light strip around it. The overall look and feel is very simple but exquisite.
In terms of configuration, it adopts a 2.25-inch full-frequency unit + 2 passive radiators, and a top sound guide cone structure to achieve 360° omnidirectional sound output. The sound quality is tuned by HARMAN, and supports innovative computational audio technology real-time dynamic tuning and nightingale algorithm. In other aspects, it supports two devices to form a stereo, up to 8 devices are interconnected; it supports UWB music relay to achieve seamless music transmission; with the “Xiaoai classmate” intelligent assistant and Xiaomi’s powerful IoT ecosystem, it provides a high-quality smart speaker experience.
52audio previously teardown the Xiaomi FlipBuds Pro, Xiaomi Air 2 Pro, Xiaomi Air2 SE, Xiaomi Air 2S, Xiaomi Air 2, Redmi AirDots 3 Pro, Redmi AirDots 3, Redmi AirDots 2, Redmi AirDots, as well as Xiaomi xiaoai portable speaker and other 16 products of Xiaomi, let’s take a look at the internal structure of this product.
| Xiaomi Sound smart speaker teardown
After reading the out of the box, we have a detailed understanding of the appearance design of the Xiaomi Sound high-fidelity smart speaker. Let’s enter the disassembly part to see the internal structure and configuration.
The body fixing screws are hidden under the non-slip mat.
Peel off the non-slip pad.
The inside of the non-slip mat is fixed with glue and positioning posts.
Remove all screws on the bottom cover of the speaker.
Mainboard USB debugging interface.
Remove the bottom cover to see the main board unit of the speaker.
Inner connection structure of cover plate.
There are multiple connectors around the motherboard to connect internal components.
Pick up the connector to open the motherboard, and there are wires on the inside that are connected to the socket of the motherboard.
The main board is removed, and the internal structure of the cavity is also provided with a cover to separate the main board and internal components.
Metal heat sink on the cover.
The speaker unit is connected to the metal contacts of the motherboard.
Circuit on the motherboard side.
The circuit on the other side of the motherboard is covered by two shielding covers on the left side.
The metal shield is provided with a heat dissipation pad, which is connected to the metal heat sink on the cover plate to reduce the temperature of the system during operation and ensure the stability of operation.
Two silk-screened 34K MOS tubes.
The regulator IC of silk screen 9J, the actual model is JOULWATT JW7805-1.8, is a 1.8V~5.5V/300mA linear voltage regulator, supports fixed voltage output: 1.0V, 1.2V, 1.35V, 1.5V, 1.8 V, 2.1V, 2.2V, 2.5V, 2.7V, 2.8V, 2.9V, 3.0V, 3.3V, 4.2V, 5.0V. Integrated over-current and over-temperature protection, support output discharge function, plus or minus 2% output voltage accuracy, low noise, quiescent current as low as 6uA, available in SOT23-5, DFN1X1-4 package, moisture sensitivity level is level 1 (Moisture sensitivity level ), has been widely used in consumer electronics, storage and other products.
JOULWATT JW7805-1.8 detailed information.
The step-down IC of silk screen JWK8J, the actual model is JOULWATT JW5250S (SOT23-5), is a 2.7V~6V/1A synchronous step-down converter, 1.5MHZ switching frequency, quiescent current as low as 40uA, peak efficiency as high as 92% , And integrated input hot-swappable protection function, provide SOT23-5/SOT563 package, moisture sensitivity level is a (Moisture sensitivity level), has been widely used in consumer electronics, storage, Netcom, TV, security and other products.
JOULWATT JW5250S detailed information.
The step-down IC of silk screen JWF5J, the actual model is JOULWATT JW5223 (SOT23-5), is a 2.5V~6V/2A synchronous step-down converter, 1.5MHZ switching frequency, quiescent current as low as 40uA, peak efficiency as high as 94% , The light load efficiency is higher than 85%, and the input hot-swap protection function is integrated. It supports the provision of SOT23-5/6 (Power Good) package, and the moisture sensitivity level is level 1 (Moisture sensitivity level). It has been widely used in consumer electronics, Storage, Netcom, TV, security and other products.
JOULWATT JW5223 detailed information.
ESMT F59L2G81KA 2Gbit (256M X 8) 3.3V NAND flash memory, used to store firmware files.
ESMT F59L2G81KA detailed information.
The laser carving 117ANC MEMS microphone is equipped with a total of 6 MEMS microphones around the main board to form a 360-degree pickup array to improve the accuracy of voice interaction. According to 52audio, the 6 microphones are all from Knowles, model: SPH0655, which is a microphone with a PDM digital interface. This microphone has a high signal-to-noise ratio and creates the necessary conditions for long-distance sound pickup of smart speakers. Tolerate sound sources with higher sound pressure levels, making the placement position inside the smart speaker more flexible.
Silk screen J5BXI IC.
TI TAS5825M audio amplifier is a stereo, high-performance closed-loop Class D amplifier with an integrated audio processor and input capability up to 192kHz.
Audio amplifier output filter inductance and power supply filter capacitor.
Connect the two metal contacts of the speaker unit.
Remove the shielding cover, and there is also a heat dissipation pad on the inside to dissipate heat for the internal chips.
Realtek RTL8733BS WiFi and bluetooth combo single chip solution, WiFi specification 802.11abgn dual-band 1T1R and bluetooth 5.2, is a WiFi4 Combo network card.
The dual-band capability can provide stable WiFi throughput in a relatively clean 5G frequency band, providing fast networking and lossless high-quality music transmission.
When the 2.4G BT Mesh bluetooth networking application is turned on, smart devices such as bluetooth buttons, doorbells, etc., can coexist perfectly with 5G WiFi frequency division and simultaneously use it to enhance the user experience.
In bluetooth 5.2, LE Isochronous Channel, commonly known as LE Audio, can provide multi-channel simultaneous transmission to achieve low-latency stereo and home theater audio modes.
At present, Alibaba Tmall Elves, Himalaya, Sony, Yandex, Mybox, Telefonica, DT and other smart speaker wireless solutions use a large number of Realtek WiFi/Bluetooth Combo network cards.
Allwinner R329 AI voice dedicated core, built-in dual-core A53 1.5GHz, dual-core HIFI4 400MHz (2MB SRAM), Arm China Zhouyi 0.256T AIPU; integrated multi-channel audio ADC and audio DAC; built-in DDR design is streamlined, it is very powerful intelligent voice with AIPU chip. Allwinner R329 can provide highly integrated application solutions for smart speakers and smart homes.
Allwinner Allwinner R329 details.
Continue to disassemble the speaker, first remove the outer transparent shell.
Inside the transparent shell.
The side of the internal cavity shows 1, the female socket of the DC power input interface.
Display 2 on the side of the internal cavity, hanging passive radiators.
3 is displayed on the side of the internal cavity, and the UWB small board is fixed.
4 is shown on the side of the internal cavity, and a WiFi antenna is fixed.
The bottom cover plate fixes the frame.
A close-up of the female socket of the DC power input interface, the solder joints are covered with heat-shrinkable tube insulation, and the wires are wrapped in foam to prevent noise from resonance.
Close-up of UWB communication module, the module is welded on the cable.
A close-up of the passive radiator, 54mm x 44mm in size, to enhance the low frequency volume.
Patch WiFi antenna, from South Star.
On the front of the UWB communication module, the antenna is on the right side, the UWB chip on the left is covered by a shielding cover, and the module is welded on the flexible cable.
Double-sided tape is attached to the back for fixing on the speaker body.
The Qorvo DW3210 UWB chip is a second-generation fully integrated pulse radio ultra-wideband (UWB) wireless transceiver DW3000 series.
Based on the IEEE802.15.4z standard, DW3210 implements enhanced security functions. The DW3210 can achieve a data rate of up to 6.8 Mbps, while providing precise positioning within 10 cm for distance measurement, and angle measurement within a standard deviation of 5 degrees. The UWB music relay function used in the speaker on this product can realize seamless music transmission by approaching the speaker with the mobile phone.
Qorvo DW3210 details.
The outside of the metal heat sink.
Inside the metal heat sink.
Remove the top cover, and the inner circular sound hole cover.
The full-frequency speaker unit inside the cavity, the rubber edge of the paper cone, is fixed by four screws.
Take out the full-range speaker and the internal structure of the cavity. The speaker wire is wrapped in foam and sealed with a lot of glue at the wire through hole.
The inner side of the full-range horn is provided with a buffer pad to seal and waterproof and reduce cavity resonance.
The back of the full-range speaker, silk screen information ASDPD0003-0301.
Full-range speaker wire connection terminal.
A buffer rubber cap is arranged on the cover plate of the sound hole.
Cushion rubber cap.
Inside the sound hole cover, the white sticker is the wiring position, which is fixed by double-sided tape.
The outside is covered with a fine dust-proof net to prevent foreign matter from entering the cavity.
On the back of the top touchpad, the cover is fixed by two screws, and the cables are perforated.
Remove the screw to open the cavity.
The inner side of the back plate is entirely white to make the scattered light more uniform, and the surrounding edges are transparent to form a circular light strip.
Inside the top cover, there is a small circular plate in the middle, and two touch sensors at both ends.
The cable extending from the main board is connected to the wire board through the connector, and is affixed with adhesive tape to strengthen the fixation.
Remove the small board, there is a touch sensor below, corresponding to three touch buttons.
There are 9 LED indicators around the small board circuit.
RGB LED indicator light.
Chipsea CSA37F71 touch detection IC is Chipsea’s new generation pressure sensor conditioning chip. Compared with the previous generation product CSA37F61, the measurement accuracy of this chip is increased by 4 times, and the power consumption is reduced by 30%. Button functions can be implemented on a thicker metal plate, bringing a richer human-computer interaction experience to smart homes.
All components of Xiaomi Sound high-fidelity smart speaker.
As Xiaomi’s first high-end smart speaker, Xiaomi Sound has a brand-new design in appearance, the overall look and feel is extremely delicate, and the materials used are also ingenious. The transparent body shell can be integrated into various usage scenarios, showing a different sense of gloss. The top touchpad is designed with a circular indicator strip, showing a similar floating effect. The only shortcoming is that there is no built-in battery, so you need to consider the placement of the power cord.
The internal structure is mainly divided into the bottom main board unit, the middle speaker unit and the top touch unit. The overall structure is interlocking, and the components are connected by various connectors, which improves the convenience of assembly.
On the bottom motherboard, there are 6 microphone units around to form a 360-degree pickup array, equipped with Allwinner R329 AI voice dedicated core, to achieve precise voice interaction; the main control chip is Realtek RTL8733BS WiFi Bluetooth Combo single-chip solution, dual The frequency capability can provide stable WiFi throughput in a relatively clean 5G frequency band, providing fast networking and lossless high-quality music transmission; audio amplifier is TI TAS5825M, integrated audio processor and input support up to 192kHz; and ESMT F59L2G81KA for storing firmware NAND flash memory, JOULWATT JW7805, JW5250S, JW5223 step-down IC, etc.
The full-frequency horn unit and two passive radiators are fixed on the internal frame, and WiFi antennas and UWB communication modules are also fixed around. The UWB communication module uses the Qorvo DW3210 ultra-wideband chip, based on the IEEE802.15.4z standard, supports high-speed transmission, precise positioning, and is used for the UWB music relay function of the speaker. There are three touch sensors inside the top touch unit, equipped with CHIPSEA CSA37F71 touch detection IC. There are 9 LED indicators around the small board, with a variety of different colors, used for voice interactive feedback.
On the whole, Xiaomi Sound smart speakers, whether in appearance design, internal structure, and workmanship, have been greatly improved compared to previous products. The latest configuration scheme, 360° omnidirectional sound speaker system, HARMAN tuning, and innovative computing audio technology provide powerful audio effects for the compact body. The application of UWB connection technology also brings a more convenient user experience.