# Ear Evaluation# Select Feiao M15 Experience Sharing

song sings well, I chose you, you chose me, this is our choice. In fact, shopping is the same as finding a partner, two-way choice. The manufacturer chooses a certain design, and the consumer recognizes that he likes it and buys it. We always make choices in our life. That's why I have the popular phrase that I want to make fun of (laughter). After experiencing the deep cultivation of the middle and low end, Feiao presented his accumulated technology at one time and made a concentrated display. I will analyze Feiao's choice from four aspects of external and internal sound quality matching function.

Functional Selection

looking at it comprehensively, the shape of M15 is more stable and atmospheric. under large volume, a relatively smooth transition is used to reduce the sensory impact caused by thick and large. in fact, it looks smaller than M11P, and its weight is also controlled within the range of one-handed holding (310g), which is a portable and practical design. It doesn't matter whether it looks good or not, what matters is practicality. I think this is Feiao's core choice in appearance, but the packaging is absolutely high-end, and the innermost packaging is a North American black walnut box.

the appearance design of M15 was very clear at the press conference this time, due to functional requirements, so we don't have to worry about whether it is a Roman column. As far as I am concerned, M15 is more like Q1MKII, especially when used as USB DAC. The knob and jack are at the top, and the charging data port is at the bottom, just to facilitate the use under USB DAC. The arrangement of flat placement is the same as that of ordinary ear placement. The waist on both sides is easy to hold, the keys are on the left, and the large key form is convenient for blind operation. Since the 5.15-inch screen is used like M11, it seems that the screen proportion is not as large as M11, but there is no difference in actual display. With Corning curved glass, the actual rest screen effect is better. The desktop is very confident to use the circuit board as the default desktop, which can be said to be a good display for itself. The weight is not much different from my current main M11P stainless steel. I personally feel more comfortable with this slightly heavy hand feeling.

actual operation experience, due to the existence of the entity HOLD key, the chance of accidental touch is greatly reduced. The analog potentiometer has excellent hand feeling, the volume control is very accurate, the key hand feeling feedback is very good, and a blue light ring also makes the whole machine feel more scientific and technological. The key stroke of the key is slightly shorter. A custom function key is added at the lower part, which can quickly operate the commonly used functions in the form of keys. Personally, Bluetooth reception mode is set, which is very fast. The system follows the M11 system. After polishing the two products, the current system can be said to be very comprehensive and the use experience is very smooth. Coupled with more professional USB DAC and Bluetooth receiving functions, it is very strong in operation and practicability. Compared with M11 system, M15 has added big ear mode to the drop-down menu, and four modes can be directly selected in the working mode, which is more intuitive. The most important thing is endurance. The M15 is equipped with a 7490mAh large battery, so even if the power consumption is large, it can still maintain a balanced endurance of more than 8 hours, making the M15 have excellent comprehensive experience.

Selection of aggregation

Feiao has always given people the feeling of stacking materials. In my opinion, whether stacking materials depends on whether they meet or exceed the design requirements. Just like Bugatti's W16 engine requires 7 engineers to assemble 3000 parts in a week. Whether it is necessary or not is due to design requirements, not looking at more or less.

in my personal opinion, M15 circuit integrates all the essence of Feiao, ADC volume control (using analog potentiometer to block corresponding digital volume, q5/q5s application),LPF and DRIVE discrete design (M11P application), core board design (M11/M11P application), Bluetooth receiving board (q5/q5s application), and the latest 4499 decoding chip, with precise overall layout, integrate the player, Bluetooth decoding and USB decoding earpiece into one machine. Here are two official pictures of Feiao to talk about Feiao's design from the process.

the basic power supply of the whole machine is mentioned. Feiao divides the power supply into three parts: system power supply, decoding power supply and analog amplification power supply. The system uses four-way power supply used on M11. Eight ways are used for decoding power supply. Four ways are guaranteed to 4499 the large power eater. Then two groups of positive and negative two-way power supply are guaranteed to ensure I/V and LPF. The analog uses independent converters and, ensure the power supply of 5V and 7.5V of the analog amplifier circuit. The overall power supply is designed with filtering, and the overall power supply provides a solid foundation for M15 pure and low noise sound bottom.

let's look at the hardware design of M15. M15 has three signal sources, namely local, Bluetooth and USB, which correspond to the main control 7872, CSR8675 and Xmos XUF208 (streaming media signals are also 7872 responsible, so local) to process, supporting almost all mainstream Bluetooth formats for playback and transmission and reception at present. Feiao has configured a 24M active crystal oscillator on each processing module for synchronous preprocessing. After that, the signal will be processed on FPGA. M15 is finally equipped with NDK customized advanced crystal oscillator (-140dBc/Hz @ 1kHz. how do you understand this index? please refer to the index of Crystek CCHD-950 commonly used in advanced machines:-143 dBc/Hz @ 1kHz or MSB galaxy femtosecond clock FEMOTO140 index-120dBc/Hz @ 1kHz), and the clock is synchronized with the third generation algorithm, then the signal will enter two AKM4499 for decoding (one chip is responsible for one channel at single end), and then output to four 1612 for I/V conversion (current signal to voltage signal), and then two 2211 for LPF (low pass filtering) to complete the decoding process. A total of four 1622 make up the whole analog amplification part. I think there are two bright spots in this part, one is hardware gain and the other is power supply voltage switching, as mentioned earlier. The gain adjustment at the output stage is also the basis for the power supply and gain switching at the physical stage to reach 280mW @ 300 Ω in Feiao Big Ear Mode. In my opinion, this design is of great significance. Looking at this process, I personally feel that Feiao has chosen a more professional circuit design rather than stacking materials.

Federation

4499 is a chip that is too new. In order to better play the performance of this high-end DAC chip, Feiao chose to debug it with Asahi Huacheng. After obtaining Asahi Huacheng's full affirmation, the final plan was determined. The efforts made for better quality are rewarding. I have heard that the future feeling is a more comprehensive player, the main reason for giving me this feeling comes from the intermediate frequency performance improved by Asahi's participation. Generally speaking, the analysis and quality of M15 is one of the best players at present. What is more valuable is that it has excellent performance in dynamic performance, which makes it have good performance in driving large headphones,

Compared with the previous M11P equipped with THX AAA amplifier, I feel that M15 emphasizes analysis and comprehensiveness, while M11 emphasizes restoration and nature. The two machines have different orientations. M15 I said comprehensive, lies in a rich sense of space under the framework of a solid low frequency, full intermediate frequency, a dye-free high frequency, the adaptation of music types more diverse. The sound bottom of M15 is very good, clean and delicate, the sound field is open and has a sense of space, and there is no feeling that can be stretched.

is the dynamic, which is the short board of the general portable player. The impact force can be clearly felt on M15. Under this dynamic blessing, the low frequency reduction is very in place, the speed sense is very accurate, and the attenuation and diffusion are very natural. There is strength and dive, but it does not cover up the sound, nor is it isolated. I am very satisfied with the low frequency performance of M15.

the intermediate frequency is changed from the previous processing method of Feiao. Under the premise that the sound field is not compressed, the intermediate frequency junction is relatively large and forward. In a warmer atmosphere, the details and emotions are abundant, making the intermediate frequency perform better than the previous Feiao player. The interpretation of vocal music is very brilliant. The positioning of the human voice is excellent and the levels are clear. The voice and lip sounds are well displayed. The sweetness of listening to female voice is obvious, but it is not too greasy. There are also many bonuses for small instrumental music. The details of the instrument are easier to be perceived and the details of the instrument are presented more clearly. However, it also magnifies the shortcomings in the recording. Personally, I feel that with the blessing of good recording, I can give full play to the intermediate frequency characteristic of M15.

M15 does not have too much dyeing on high frequency, it is basically a sound of reduction direction, the brightness extension is very good, and it also shows clearly the extremely high frequency. The attenuation speed is slightly different according to the final effect presented by different earphones. In the end, high frequency is the easiest place to understand and have differences, providing a basic reduction state and giving it to earphones to show their own characteristics, personally, I feel this is also a good choice for a front end.

In earplug mode, I personally use IE800S, IT04 and FH7 earphones with different styles to listen. The styles presented are also various. Generally speaking, compared with M11P, it strengthens the sound field space sense and low frequency quality of earphones, fills the energy and expressiveness of intermediate frequency, enriches the details and extension on high frequency, and can hear the sound relatively warm under any earphone, this overall style makes the sound more comprehensive, which can be said to be classical pop-take-all, with good performance in both vocal and instrumental music.

big ear mode is the main mode of M15. In big ear mode, I first use HD700 and HD800S to listen. The listening feeling of these two earphones is also the reference earphones for me to get the listening feeling above. The driving of H700 in M15 has reached the level of a machine. The sound field is turned on and the low frequency has a sense of energy. It also makes up for the problem that HD700 has a lower intermediate frequency on ordinary machines. The gorgeous feature of high frequency is not discounted, which is my favorite match. HD800S is more quality than the combination of x7ii k5 in my impression. It can be said that it is more reliable than many thousand yuan machines. I am personally very satisfied with the performance on my own. The sound integrity is very good, the sound field matches the amount of information, and the sense of space is very good, but it is much worse than the performance of my own machines.

, for better reference, I also brought two closed earphones, elega and stella, which are strong waves. One special thing about these two earphones is that there is a huge gap between them on the stage. It also happens to see to what extent M15 can be pushed. As for elega, which is directly pushed by positioning, I personally feel that although it is slightly different from that on stage, it is basically the difference of driving force. The amount of information and low frequency are completely satisfied, and the sound has a good performance in popularity. On the stella, there is still a little lack of control. The sound field is slightly squeezed compared to the machine, and the listening system is a bit mixed. However, it can be clearly felt that the improvement of stella relative to elega is more obvious than that in other front ends. Personally, I think this is very rare as a carry-on. After all, it is unrealistic to require a high-control earphone to be driven with you.

Generally speaking, M15's big ear mode is personally suitable for headphones with high impedance, but not for headphones with high control force. For example, stella's resistance is much smaller than HD800S, but the final effect is not as good as 800S. I think it is more representative. HD700 is the earphone that I personally feel most matched when listening to it. The sound gives full play to its own advantages and makes up for some deficiencies, making the sound complete. The driving effect of elega is also very good and the style matches. However, I personally prefer HD700 (it may also be related to my high frequency performance of elega). As for the flagship HD800S and stella, they said they could achieve high performance, but they were still too demanding.

said that he wanted to make a digression here. When listening to HE1 at the party, he chatted with Senhai staff. He repeatedly stressed that HE1 performed better on high-rate music. Finally, he replaced the CD turntable we prepared with MAC computer to support DSD and Hires music. I think, perhaps this is the manufacturer's attitude towards high-rate music support. Every product cannot be separated from the background of its birth. As mentioned earlier, M15 not only enhances the performance of music, but also magnifies the shortcomings of music. As a result of my personal listening, M15 performs better for the newly mixed and converted high-rate albums. I am a person who listens to classics and belongs to the type that can no longer be vulgar and vulgar. It is also because of this that I will have multiple versions of the same recording. For example, Bo Si, directed by Little Kleber, I have two versions of CD and SACD converted by Yisow. In 1963, Karajan conducted Beethoven's Symphony. I have three versions of CD, 24/96 and SACD. The code rate of, it is often the new album version that has a clearer sound and is more suitable for M15 playback. Personally, I feel that recording is now like high-definition video, thinking about the development of high-definition. It can be said that M15 is also following the trend of this high-definition era and choosing to present users with a clearer and high-quality voice.

Possibility

Feiao has been working hard on its functions. I will not repeat it after writing relevant posts before. At present, Feiao M15 covers many functions in streaming media and Bluetooth, all in order to have more and better ways and choices to listen to songs, allowing users to choose their own way of use, which meets the various needs of customers and can explore various possibilities, which is also a kind of fun.

M15 directly uses four modes to switch to different usage scenarios: Android mode, pure tone mode, Bluetooth receiving mode and USB DAC mode. Bluetooth mode and USB DAC mode are also integrated into the scene mode selection, which is more intuitive and more convenient. In addition, the operation of custom keys is more convenient, and the functionality of M15.

Since M11 optimized the algorithm, the delay of USB DAC is also very low, and the delay of Bluetooth is almost unknown. However, in actual use, M15 with hardware support is comprehensive beyond M11 optimized by software in these two functions. The support format and stability of USB and Bluetooth are not the same. USB DAC can support DSD512 and 768, and Bluetooth reception and transmission support the current mainstream format, it also makes M15 more professional. The sound of Bluetooth receiving mode is slightly different according to the front end. Personally, when I use M11P, it is basically the same as that of this machine. When I use my mobile phone, I play the sound slightly. I personally feel that the USB DAC mode is a mode that surpasses the playback level of this machine, with clearer sound and better sense of space. With the support of hardware, it can be said that these two modes are also very professional and excellent.

in such a multi-function, I share with you three modes with better personal experience: one is the coaxial output desktop decoding of Bluetooth receiving mode. I experienced the convenience of Bluetooth receiver in my friend's house before, but now it is the mode I use more personally, because I lack a Bluetooth receiver and sometimes want to listen to songs on my mobile phone. This mode becomes very important to me, m15 basically has no delay in this mode, giving full play to its turntable advantages. Another mode is that the mobile phone LINK operates M15 coaxial output, which directly turns M15 into a digital broadcast and acts as a function of turntable. After using it, I feel that it is one of the best performance of the portable turntable at present. Relying on M15 's better receiving chip and better FPGA algorithm and crystal oscillator, the sound background is quieter than M11P stainless steel, which has obvious advantages in space sense and positioning. The last one is LO port. I like to listen to the car when I go to and from work. I can listen while charging with the filtered car charging line provided by Feiao. The overall sense of space and low frequency dynamics are very good. In addition, the car mode interface designed by Feiao (there is also a special car mode, the machine will start and shut down with the car, but I personally can't use it). The use experience is very comfortable.

Of course, for me, I hope Feiao can add UPnp protocol to support DLNA delivery and reception, instead of only supporting reading DLNA devices at present. In this way, Feiao player can be directly used as a network playing device to directly connect the network bridge and the smart speaker in the home, so that the playing medium can be expanded again and more practical scenes can be enriched.

Feiao chose to make M15 an aggregate product of all the technical essences of Feiao. It has a high level of functionality and sound quality and has excellent experience. I regard M15 as Feiao, taking the best product form in my mind as the summary of this stage, carrying the accumulated technology and experience of Feiao, and finally letting users choose. However, in my opinion, if you want to choose a player with a good comprehensive experience at a high price, M15 may give you no choice.

author:chen_racon03-03 16:52

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