The reason why the mobile phone cancels the 3.5mm headphone jack

I believe everyone has discovered that the 3.5mm headphone jack on our mobile phones is slowly disappearing, but do you know why the 3.5mm headphone jack is canceled on mobile phones? The following is my objection to the reason for canceling the 3.5mm headphone jack on the mobile phone and the reason analysis. Maybe my analysis is not professional enough, and there may be mistakes. I hope everyone can help point it out, so as to help more people who don’t know.

Reasons for canceling the 3.5mm headphone jack

1. Cancel the 3.5mm headphone jack in order to make the phone thinner and more waterproof?

The thinnest phone that actually has a 3.5mm headphone jack is the vivo X5 Max, which was released on December 10,2014.

The thickness of the vivo X5 Max is only 4.75mm, so it is difficult to stand on the claim that the 3.5mm headphone jack is canceled in order to make the phone thinner. Regarding the statement that the 3.5mm headphone jack is canceled to make the phone more waterproof, I have also found evidence that can deny this statement. Example: Galaxy S5 released on February 24,2014

It is also a mobile phone equipped with a 3.5mm headphone jack. The waterproof performance of the earphone jack can reach IP67 without using any equipment to block the earphone jack. A 2014 mobile phone can achieve IP67 waterproof performance, so It is obviously untenable to cancel the 3.5mm headphone jack of the mobile phone in order to improve the water resistance of the mobile phone.

2. Using the USB-c interface can make the phone's sound quality better?

When it comes to the sound quality of mobile phones, we first need to understand how mobile phones sound? You can read the second section of my previous article "Factors Affecting the Sound Quality of Mobile Phones" - DAC decoding chip, which explains the process of mobile phone sound.

The binary audio file stored in the mobile phone is converted into PCM signal through the built-in Digital to analog converter of the mobile phone into an analog signal, and then drives the speaker to sound. There is a certain relationship between the sound quality of mobile phones and the DAC decoder. Just using the USB-c interface can make the sound quality better. Obviously, this statement is wrong.

Knowledge:

The 3.5mm earphones receive analog signals. When using a common type-c to 3.5mm adapter cable, it relies on the built-in DAC decoding chip of the mobile phone SOC (some mobile phones use a built-in independent DAC decoding chip) for digital-to-analog conversion (digital signal converted to analog signal) to make the 3.5mm headphone sound. The output of the USB-c interface is a digital signal, which needs to be used with headphones with a DAC decoder chip or a type-c to 3.5mm adapter cable with a DAC decoder chip. Therefore, the cancellation of 3.5mm is more to reduce the dependence of the mobile phone's sound quality on the mobile phone's DAC decoder.

3. Are Bluetooth Headphones Better Than Wired Headphones?

Bluetooth headsets make people get rid of the shackles of wires, but Bluetooth headsets have more defects than wired headsets:

l worse sound quality

The working principle of the Bluetooth headset: the mobile phone/computer decodes the audio file into PCM code, and then encodes it into Bluetooth audio (SBC, AAC, APTX, LDAC, LHAC) and then transmits it to the receiving end (Bluetooth headset). The Bluetooth headset encodes the Bluetooth audio ( SBC, AAC, APTX, LDAC, LHAC) are decoded into PCM codes, and the PCM codes convert digital signals into analog signals through the DAC decoding chip and AMP (Operational amplifier) to drive the speaker of the Bluetooth headset to sound.

Obviously, the working principle of the Bluetooth headset is more complicated. Due to the small size of the headset, the performance of the chip is greatly limited, and there is packet loss in the Bluetooth wireless synchronous transmission, which makes the sound quality of the Bluetooth headset degrade more obviously.

l Significant power consumption

In addition to audio decoding and encoding, the mobile phone SOC also needs to supply power to the Bluetooth module, which makes the Bluetooth headset consume more power than the wired headset, and the power consumption of the Bluetooth headset is about 1.6 times that of the wired headset.

l Playback delay

When Bluetooth transmits audio data, it will go through steps such as data compression, wireless transmission, data decompression, and digital-to-analog conversion. If the Bluetooth transmission protocol used by the Bluetooth headset is lower than Bluetooth 5.0, the delay of the Bluetooth headset will be more obvious.

l Battery battery life

The battery life of a Bluetooth headset is about 3 to 4 hours, and the headset can no longer provide sound playback when it is out of power, so it is not suitable for users who use the headset for a long time.

Personal analysis of the reasons for canceling the 3.5mm headphone jack

1. Promote related products

l Transfer cable

The cancellation of the 3.5mm headphone jack will make it impossible for many users who use 3.5mm wired headphones to continue to use them, so that wired headphones must be used with a USB-c to 3.5mm adapter cable or a lightning to 3.5mm adapter cable. However, some mobile phone manufacturers do not give away adapter cables when they sell mobile phones. The purpose is simply to hope that you can buy additional ones.

l type-c/lightning earphones

The cancellation of the 3.5mm headphone jack will cause many users who like direct connection of wired headphones to choose to re-purchase a type-c headset or lightning headset, creating a sales market for new styles of wired headphones.

l Bluetooth headset

Canceling the 3.5mm headphone jack will make some users more willing to use wireless headphones, and if the battery inside the Bluetooth headset is too worn out, it will be troublesome to replace the battery by yourself, and it will be expensive to find a brand for after-sales maintenance. This makes Bluetooth headsets a consumable, making mobile phone manufacturers more profitable in Bluetooth headsets.

And the Bluetooth headset also has brand compatibility, and the products of the original manufacturer's brand can be used normally. For example: If you use a Bluetooth headset that is different from the mobile phone brand, there will be intermittent no sound from the headset. It makes everyone have to buy the original manufacturer's brand, and the price of the original manufacturer is often expensive.

2. Increase maintenance cost

The mobile phone manufacturer presents an ordinary USB-c to 3.5mm adapter cable, which does not support charging and supports audio output function at the same time. The wear and tear also creates conditions for mobile phone maintenance.

3. Save manufacturing cost

The price of the mobile phone headphone jack cable is about 1～2$, of course the cost must be lower than this. Read on and you'll change that mind.

The above data comes from Counterpoint's "Global Smartphone Market Share: By Quarter"

According to statistics: the total sales of iPhone mobile phones in 2021 will be 237.9 (in Millions), so canceling the 3.5mm headphone jack will save the iPhone 4.758 billion US dollars. After reading this value, do you still think it is a decimal value?

Summarize:

I think the reasons given by mobile phone manufacturers for canceling the 3.5mm headphone jack are absurd. The cancellation of the 3.5mm jack also makes the use of wired headphones more troublesome. I believe everyone can understand the purpose after reading my personal analysis. In my opinion, a good product should aim to solve customer pain points, rather than create new pain points for customers.