``A different world'' from 1000 yen products, Sony's high-end wireless earphones teardown: What happened in the last decade, what will happen in the next decade (54) (1/3 page)

Wireless earphones that can now be seen even at “100 Yen”

Sony June 2021 On the 25th, the wireless headphone "WF-1000XM4" with a noise canceling function was released. There are many wireless headphones on the market today. It has become so common that it is sold at large electronics stores, home centers, drug stores, and 100-yen shops. Inexpensive ones are under 1000 yen (998 yen at Sundrug: body price). Wireless earphones are coming to an era of 1000 yen.

On the other hand, Sony, Apple, BOSE, Yamaha, etc. sell so-called high-end wireless earphones for tens of thousands of yen. High-end machines have high sound quality that matches the price, and the wireless performance is also very high. Sony has released a large number of wireless audio products such as overhead and earphone types, and has a good reputation for noise cancellation. The latest WF-1000XM4 is twice as small as the previous model "WF-1000XM3", and uses Sony's original audio processor "V1".

Figure 1 shows the WF-1000XM4 packaging box, earphones (one side: symmetrical), internal removal, and the battery. The batteries are from ZeniPower in Hong Kong. The previous model also used a ZeniPower battery, but the new model has a battery capacity that is about 20% larger. Despite the miniaturization, the battery capacity has increased, so we can read that the WF-1000XM4 has undergone a major design review.

As shown on the right in Figure 1, there are two boards inside (including flexible wiring) ) and drivers. The board on the driver side has a MEMS motion sensor and a MEMS microphone to catch the sound of the driver and perform back processing. The other board has a V1 processor for Bluetooth and audio processing, and two MEMS microphones for forward processing to catch external sounds. In addition, a battery charging IC and flash memory are also installed.

Figure 2 shows how the driver is disassembled. The driver is 6mm in diameter. It is completely different from wireless earphones of 1000 yen. It is covered with strong metal, and on the outside, the entire driver is fixed with strong plastic, as shown in the upper left of Fig. 2. The driver part is protected double and triple. 1000 yen wireless earphones cover the driver only with the housing, and the removal can be done in one process, but with the WF-1000XM4, it is removed from the plastic chip, the metal frame is removed, and finally the driver is reached. It is a solid construction with a closed dome shape. Inside the driver, a neodymium magnet is used, which surrounds the coil in a circle.