Digital interface to noise reduction?
last yeariPhone7 cancel the headphone jack with two big headphone industry, one is all wireless, the other is a digital interface headset. All wireless representatives of products is Airpods, and other manufacturers have experienced all the wireless products for the time being can not pose a threat to Airpods. The digital interface headset is now very popular, many Android phones also cancel the 3.5mm headphone port, most of the headphones are also Type-C digital interface headset, although not charging while listening to songs highly criticized, but enthusiasts can use mobile phones When the turntable, external amplifier for better sound quality can be considered a little after the removal of the benefits of 3.5. But in the standard headphones to join active noise reduction, in addition to the year Sony, few manufacturers try.
The MDR-NC750 is Sony's active noise canceling headphone for home-use handsets. Not to mention the noise reduction effect, let's take a look at this headset noise reduction principle. The general principle of active noise reduction headphones We have said in previous articles, roughly through the headset mobile phone noise environment, the headset itself to calculate the reverse sound waves, play and offset. Sony this with his own mobile phone headset as well, but the difference is that this part of the headset noise reduction operation in the phone, the headset can be as portable as ordinary headphones. Careful observation is not difficult to find, this headset pin more than the general wire headset, I guess should be the environmental noise feedback interface.
As a result of the 5-pin, so it explains why this headset only in a specific type of Sony mobile phones have a noise reduction effect. Because there is no conventional wire control device on this earphone, but with 5-segment design, the author looks at the introduction of this earphone, and the earphone can also take any side of the microphone while calling. So you can be more sure guess this section of the headphone 5 contacts in turn have GND, left noise reduction microphone feedback, right noise microphone feedback, left speaker, right speaker. If the left and right channel noise is collected separately, then the noise reduction effect should be quite good. The above is the author based on the headset to make a reasonable guess, but this headset I really did not used, useful partners may wish to comment to share your views.
Since the 3.5mm socket will be able to meet the noise reduction needs, then why the type-c and lighting digital interface popularized only slowly began to have a cell phone noise reduction?
Product: Lightning In-ear Headphones Libratone Headphones 2 The standard Active Noise Reduction is the trend
Standard active noise reduction is the trend
For Type-C, for example, Type-C has a higher bandwidth and more data throughput than a 3.5mm audio interface. Neither noise nor music signals have a bottleneck in the transmission rate. UsediPodShuffle's friends must know, shuffle's 3.5mm interface set charging, listening to songs, transmitted in one, the transmission rate of song people crazy. So if you use 3.5mm transmission, then the sound signal, the noise signal, offset the noise signal may encounter transmission ceiling.
Bird noise reduction module, combined with remote control, take power from the phone
Now lighting noise into the ear there are many, such as the bird's ear noise reduction, noise reduction effect is very obvious in noisy environments. There are also 1MORE and Pioneer have their own lighting noise reduction but their noise reduction algorithms are integrated in the headset. Only from the phone's lighting interface to take power. This benefit is not dragging a "chewing gum" like the traditional noise reduction ears, but the disadvantage is that there is no built-in battery, you can only use the handset to reduce noise. To say one more thing, in order to use the lighting interface, headset manufacturers need to obtain Apple MFi certification, it is still more expensive.
BOSE QC20 "chewing gum" noise reduction module comes with a battery
Why do I say after the standard mobile phone manufacturers will be a noise reduction? After the wireless headset more popular, support for 3.5mm headphone jack manufacturers will be less and less, the manufacturer comes with a random headset will be a digital interface headset. Adding headphones to the radio microphone is not difficult. And a lot of mobile phone manufacturers software technology is very strong, "call noise reduction" in the mobile phone industry has also existed, each also has its own accumulation, and the noise reduction algorithm integrated in the phone, follow-up with the system update is also very convenient.
However, handset manufacturers do noise reduction will encounter many difficulties, one of the biggest difficulties I think is the cost. Digital interface headset in principle than the average 3.5mm headphone more built-in decoding amplifier chip, but also in the headphone cavity to increase the ambient sound radio microphone, but also for noise reduction research and development of noise reduction algorithm; how to weigh the cost and noise reduction effect Has become a major difficulty, if increasing the cost of research and development noise reduction, is bound to increase the cost of the machine, affecting sales. Therefore, cell phone manufacturers do not like the headset manufacturers, "drastic" to spend money to do noise reduction, more money is used to polish the appearance of the phone, UI and other users often come into contact with the place. This is also my original headset noise reduction effect is not too good reason.
Type-C digital headphones more and more
Mentioned earlier, "call noise reduction", many of my friends easily confused with the headset active noise reduction, here a little mention. The so-called call noise reduction, and the principle of active noise reduction headset similar to the mobile phone microphone ambient sound and then calculate the reverse sound waves to offset the noise, but the difference is that you feel the noise reduction is not the other side of the handset . I particularly impressed the call to do noise reduction is a good vendor that year, Motorola, then motorized "NICAM" technology allows people in noisy environment you disguised as a quiet office.
Again, take the initiative to noise reduction, since the noise reduction algorithm can be integrated in the phone, then the collection of environmental noise through the mobile phone microphone can not be achieved in the ordinary headset noise reduction it? It's easy to do, even with just one piece of software. However, no manufacturer will do so because the relative position of the noise-canceling microphone and the earphone is not fixed and the collected noise is different. The generated reverse sound wave may not only be unable to reduce noise but also enhance the noise. At this time we think of the noise-canceling headphone microphone cavity microphone opening it, the noise collected, most of your ears will hear the noise. In this way, noise reduction will be more accurate and better.
In the future, active noise canceling headphones for use with mobile phones have a great chance of becoming a bonus product of the handsets with the popularization of Type-C. However, due to the cost, the noise reduction effect should not be too high. At this stage That can only filter out some low-frequency noise. But do not rule out a possibility is that the headphone manufacturers in the future released the cable active noise reduction digital headset will no longer noise reduction module is mounted on the headset, but the noise reduction algorithm is integrated into their own app, users need noise reduction only in mobile phones Open the application, you can enjoy the peace. I'd rather have one such headphone manufacturer: to produce their own noise reduction digital headphones, but also have their own integrated noise reduction algorithm for mobile-side applications. At the same time, the same as SONOS applications, integrated in the application of major music services. Even if the price is slightly higher, but there is a significant noise reduction effect we will pay. In this way, even if the original headset is damaged or consumers want to upgrade the headset, you can easily buy and adapt, more consumers can experience the wonderful feeling of noise reduction.
Libratone Lightning interface in-ear headphones detailed parameters