Airpods was once hard to find. Why was Helin technology’s anti-interference products selected?

Everyone wearing airpods in the subway should know that whether your headphones are intermittent “poor signal” or smooth “super anti-interference”, what determines your hearing experience is actually the “shield” of the acoustic sensor of the headset.

The shield is a kind of metal shell. The space occupied by the small earphone can only be measured in millimeters. It “covers” earphone components, wires and cables, so as to “shield” external electromagnetic signals and heat sources. Traditional earphones rely on ultra long headphone cable to conduct signals, so the problem of electromagnetic interference is relatively small. In the era of wireless headphones, the burden of “anti-interference” has undoubtedly fallen on the shielding case.

The anti-interference performance of headphones is directly related to the user experience. When the popular airpods in the world were still in the development stage, apple chose thousands of them. Finally, it was decided that goers (002241) was mainly responsible for the supply of acoustic sensors (micro microphones), and the shielding cover was the key component of the acoustic sensors.

Founded in 2012, Helin technology began to develop shielding case products as early as 2008, leading peers to market the products, and successfully entered the upstream of gol shares. Why can it conquer gol shares and apple? In 2019, the revenue of Helin technology increased by 65% year-on-year. On the other hand, the net profit decreased by 52% year-on-year. How far can the small shield support Helin technology to go?

Earphone revolution, electromagnetic interference is difficult to solve

With the advent of airpods in 2016, the headset “wireless” revolution was rapidly set off, followed by the TWS headphones of Sony, Bose and other brands, and the “true wireless” Bluetooth smart headset ushered in the outbreak period.

According to counterpoint research, in 2016, only 9.18 million pairs of TWS earphones were shipped in the world. Two years later, it soared to 46 million pairs. Since then, the annual growth rate has more than doubled. The agency predicts that the global sales of TWS wireless headphones will reach 230 million in 2020.

But at the same time, the problem of TWS earphone anti electromagnetic signal interference is still unsolved. Acoustic sensors can convert acoustic signals into electromagnetic signals. However, electromagnetic signal interference exists between left and right earphones, between different pairs of earphones, and between earphones and other electronic devices (such as microwave oven), especially in densely populated areas or when the related equipment is too close.

Therefore, the internal analog filter, digital filter and other anti-interference products emerge as the times require, which can “filter” many messy signals. People have also come up with some wonderful ways to use TWS headphones, such as changing the Wi Fi channel, turning on the Bluetooth coexistence function of the network card, and keeping away from interference sources. However, these methods can not cure the root cause.

Abandoning the idea of “filtering out” random signals, Helin technology decisively “blocks” all interference signals, which is simple and crude but effective. After years of technical polishing, the key core indicators of its shielding cover products are far ahead of the peers, with excellent quality, it has successfully attracted the attention of goer shares.


In terms of shielding effectiveness, the core index of shielding case, the shielding effectiveness of acoustic sensor equipped with Helin technology shield can reach 73-75db, while the average market level is about 70dB.

In addition, the trend of headphone miniaturization is putting forward stricter requirements on the machining accuracy of shielding case. The machining accuracy tolerance of Helin technology is controlled within ± 0.012mm, which is far better than ± 0.025mm of the industry average level. Based on the high machining precision control, the shield size of Helin technology is far smaller than that of similar products, and has successfully caught up with the miniaturized tuyere.

It is worth noting that the biggest bright spot of Helin technology winning the favor of goer shares lies in the yield rate. It has always been a difficult problem for the industry to maintain a high quality rate under the conditions of mass production and high precision processing. Therefore, the yield rate has become the “gold standard” for acoustic sensor manufacturers to select suppliers. The good product rate of Helin technology is as high as 5ppm, which means that the number of defective products that affect the quality of the final product (acoustic sensor) will not exceed 5 per million products.

In recent years, golfer has become the second largest supplier of Apple’s airpods product line, and has been supplying Huawei’s third generation TWS earphones exclusively from the “Android system”. In September 2019, it plans to raise 2.2 billion yuan to invest in the “dual ear real wireless smart headset project”. According to the annual report data of that year, the ending inventory amount is close to 5.3 billion yuan, which shows that the number of orders taken by gol is very considerable.

From 2017 to 2019, the sales revenue of Helin technology shield products from gol shares was less than 40 million, approaching 100 million rapidly, with a compound growth rate of 50%. Backed by the largest customer gol shares, and Lin Technology shield business will be able to continue the ultra-high growth rate.

The shielding case, which accounts for nearly 70% of the revenue, performs so well. Moreover, according to the prospectus of Helin technology, its gross profit margin is as high as 47%, so the overall performance will not be bad. So, where are the “doubts” of the performance of “increasing revenue but not increasing profit” of Helin technology in 2019?