Hi-Fi， High Fidelity is short for High Fidelity. This word, which has the color of "metaphysics" and haunts the fans, has been constantly upgrading with the progress of technology. From the 1950s to 1960s, when stereo was available, it was called Hi Fi. Later, subwoofer, Dolby, multi-channel, coaxial line, and even optical fiber and anechoic chamber came out. Like the story of the poor third generation of SLR, Hi Fi enthusiasts are also struggling.
However, the previous Hi Fi has nothing to do with mobile phones. Before the milestone of vivo X1, mobile phones were just electronic devices that could make sound. As the hero of bringing mobile phones into the Hi Fi era, Vivo's X series has developed into the third generation in a twinkling of an eye. Before the release of vivo X5Max, please allow the nostalgics to review the history of vivo, the mobile phone's Hi Fi hero.
Audio sampling rate defect originating from Android
Android before 2012 was not an excellent audio and video platform, because its audio system had SRC defects. SRC's full name is Sample Rate Converter, that is, sampling frequency conversion, which has been regarded as an audio quality killer by enthusiasts.
The 44.1kHz and 48kHz sampling rates correspond to common music and video audio track specifications, but Android can only work at a fixed sampling rate. If 44.1kHz is selected, 48kHz will have poor SRC. In short, if you want good music, the audio in the video will be very poor
What is more tragic is that Qualcomm, the largest smartphone chip provider, also had hardware design defects that year. It also had the problem of poor SRC at 44.1 kHz. The result is that Android has always been ridiculed for its audio quality... In that era, the peak of mobile phone audio quality was the iPhone with non Android and non Qualcomm processors, while the peak of Android was the Razr XT910, the blade of my big moto.
The first work, vivo V1/Y1
However, the poor SRC of Android is not an unsolvable problem. The problem of SRC can be circumvented through the dynamic sampling rate switching technology.
In the first half of 2012, vivo developed the VRS (full name: vivo signal Retrieval System) technology to achieve dynamic sampling rate switching on Android, thereby bypassing SRC. This technology was first used in vivo V1/Y1 and its subsequent models.
The vivo V1 still has a bottleneck of 44.1kHz due to the adoption of Qualcomm's MSM7227 chip, while the vivo Y1 using MediaTek's MT6573 processor, after solving the SRC problem, has sound quality advantages unmatched by Qualcomm's solutions in the past.
From the historical data, the voice of vivo Y1 is clean, full and dynamic. In terms of voice and mid-range performance, the analytical power is relatively better, the sound is solid, the image is good, and the style is similar to that of iPhone. However, due to the limited positioning, the sound quality of the machine is inferior to that of the iPhone.
In addition to SRSBBE sound effect technology, yamaha power amplifier and non clip anti broken sound technology, vivo has created a software environment for future hardware integration.
It is also mentioned in the historical data that because of the cooperation between vivo and MTK, Vivo's VRS technology "incidentally" benefited 50 million MTK solutions shipped that year (2012), making the MTK at that time have better sound quality than Qualcomm. Later, HTC's One X, Meizu MX2, and Xiaomi 2, which uses Qualcomm's S4 Pro chipset, also solved the SRC problem. Of course, these are the last words.
Boundary marker, vivo X1
In November 2012, the milestone vivo X1 in the history of mobile Hi Fi was released. If vivo V1/Y1 is a milestone for vivo in audio software, then vivo X1 is a milestone for mobile phone audio hardware.
In fact, the mobile phone is only a part of the entire Hi Fi system. Its main task is to convert digital signals (music files) to analog signals (audio signals). Its core is the codec chip, which is composed of DAC (listening) and ADC (recording). Generally, mobile phones use SoC integrated codec or external codec solutions.
The historical significance of vivo X1 is that it uses independent SRC and DAC chips with high power consumption and high price instead of cheap codec chips, which directly raises the threshold of Hi Fi to another dimension. Its audio subsystem has inserted Cirrus Logic's CS8422 and CS4398 DAC chips. It's like that when everyone is centralized, a unique person suddenly appears.
The CS8422 is an asynchronous stereo sample rate converter. Its "high input jitter tolerance and ultra-low jitter clock recovery" function brings relatively higher quality digital signals. It supports 24bit/192kHz decoding, has a signal to noise ratio and dynamic range of more than 120 dB, and the total harmonic distortion+noise is as low as 0.0005%. It uses a multi bit Delta Sigma modulator and integrates mismatch noise shaping technology.
The CS4398 DAC chip supports input/output ratios from 6:1 to 1:6, providing transparent conversion with a dynamic range of 140dB and a performance of - 120dB THD+N. It is mainly used in high-end audio equipment such as E-MU 1212m/1616m, Qihonghong CK4/C4 Pro, Lezhibang MD10 decoder, etc. To put it simply, X1 uses a common solution for high-end CD players and Blu ray DVD devices
In order to balance power consumption and audio performance, HI-FI mode that can be switched independently is added to the normal mode. After the Hi Fi mode is turned on, the digital signals output from the main chip MT6577 of MediaTek are sent to CS8422 for processing and then output to CS4398, bringing the sound quality level never seen on the mobile phone.
Its advantages over other mobile phones (including iPhone) in sound quality can be detected by even laymen with one ear, and even many walkmans have been killed. The overall sound of X1 follows the high fidelity line, and at the same time, it begins to add vivo's own tuning style. Its light in sound quality even "covers" its 6.55mm thickness record.
Upgrade again, vivo Xplay
In May 2013, vivo Xplay was released, which is the first mobile phone in the Xplay series. The Xplay, which focuses on Hi Fi and AV, is equipped with a 5.7 inch screen and Snapdragon 600 processor, and its pricing and positioning are much higher than the vivo X1 with MTK processor.
Xplay's audio system was upgraded again. On the X1's CS4398+CS8422 dual chips, an operational amplifier chip OPA2604 from TI was added (used to amplify the output signal). This is another chip for non mobile devices, and its popularity among audio enthusiasts is even close to NE5532.
The OPA2604 is known as the most "gall bladder" operational amplifier. It is characterized by powerful low frequency, mellow medium frequency, smooth high frequency, and extremely sweet overall sound style, similar to the taste of gall bladder amplifier (that is, electronic tube amplifier), which is favored by enthusiasts. The famous British CD player brand, LINN (Lotus Brand), loves this player. The high resolution and sweet taste it brings is also known as "Lotus Poison".
Xplay's voice is warm, medium frequency is full, and medium high frequency is dynamic They are obviously different from X1. Relying on the power of OPA2604, Xplay has better dynamic performance and details than X1. Its control power is far better than IPC level players, which also makes it go further and further on the road of killing iPhones and iPod Classics.
Here is also an off topic story. Because of the improved configuration, the Xplay using Qualcomm Snapdragon processors has encountered problems that were not found in the previous MTK scheme. The solution of CS8422+CS4398 requires the system's SoC master chip to provide digital I/O of audio. However, Qualcomm has never opened the output of chipset audio channel before Xplay. However, given the performance of X1, the design of Xplay has been supported by Qualcomm and opened the audio digital channel.
Architecture and mobility optimization, vivo X3
On August 22, 2013, the successor of vivo X1, vivo X3, was released. X3 uses MT65894 processor of MTK company, and the thickness of the fuselage is 5.75mm. The core component DAC chip of the audio architecture is replaced by the ES9018 K2M of ESS.
ES9018 chip is a DAC chip that has a good reputation among enthusiasts. It is a product of ESS company that has made a comeback and is used in many high-end CD players, Blu ray players, professional audio interfaces, sound cards, decoders and other products. The ES9018 K2M is a DAC chip customized by ESS for low power consumption, including mobile phones, tablets, etc.
The ES9018 K2M is characterized by good analytical power, slightly bright in middle and high frequencies, generally neutral, delicate and bright timbre, and no obvious warm sound and soft style.
It supports dual channel output with a signal-to-noise ratio of 127dB. The chip itself supports digital input functions such as I2S, S/PDIF, and has a built-in clock management unit, which can take over or optimize the digital signal clock input. In vivo X3, Cirrus Logic's CS8422 chip, which is used on both X1 and Xplay, can be omitted, and the maximum power consumption is controlled at 40mW.
In addition, The vivo X3 also integrates Max97220 low-voltage class AB operational amplifier of Maxin, which is used for buffer amplification of headphone output. Under 5V voltage and 32 ohm load conditions, it can provide 125 milliwatts output. It has a very good driving force in headphone output performance. Its voice is straightforward and powerful, and its mid-range dynamic performance is excellent. Its driving force is obviously superior to other mobile phones and most walkman products.
Maintain advantages and develop in various ways
The vivo Xplay 3S was released before the Spring Festival in 2014. Its screen has been upgraded from 5.7 inch to 6 inch, and its processor has also been upgraded to Snapdragon 800 (MSM8974AB). It is also the first domestic mobile phone with 2K screen and fingerprint.
The audio part of the Xplay 3S uses the same ES9018 K2M as the vivo X3, and adds the OPA2604 chip that was added to the Xplay for the first time. Half a year before the release of Xplay 3S, vivo's own customized system, Funtouch OS, added the Timeline interface as a user's operation record and personal assistant.
The vivo Xshot released in May of the same year mainly focuses on Hi Fi and photography. It uses a 5.2 inch screen and Snapdragon 801 processor. The photography part uses the strongest sensor IMX 214 sold by Sony at that time and adds optical anti shake.
Although its audio part DAC is still the CS4398 chip of Cirrus Logic, it has been customized by vivo to Cirrus Logic. It adopts the latest technology and packaging, greatly reducing and reducing the size and power consumption. In terms of operational amplifier, the Max97220 is the same as the X3.
Since the generation of Xshot, vivo has gradually demonstrated its own voice style, continuing the warm and soft style established by Xplay. Customizing DAC chips to Cirrus Logic and normalizing abnormal design is also an important sign of Vivo's maturity as an audio equipment manufacturer.
The vivo X5 was released on August 26 this year. The machine is equipped with a 5-inch screen and an MTK 8-core processor. In the audio part, the vivo X5 uses the customized CS4398 like the Xshot, and continues the soft listening sense of vivo from Xplay.
However, vivo's love of professional chips is still out of control. This time, the Karaoke digital surround sound signal processing chip YSS205X from Yamaha was put into the mobile phone. The sapphire version, which was launched one and a half months later, is the first mobile phone to use super hard sapphire glass.
The vivo X5Max will not be released until tomorrow, and its slogan "thin moving heartstrings" still refers to the Hi Fi and slim featured in the X series. The known information now is the single side critical cloth plate and multi beam wing middle frame related to lightness and thinness, and the thickness will be about 4mm. In terms of audio, the machine is likely to use new audio systems and chips.
summary
From V1/Y1 to X1, Xplay, X3 and X5, the audio scheme of vivo has never been repeated:
Vivo V1/Y1 solves the SRC degradation of Android and paves the way for sound quality in software;
X1 adopts the unconventional scheme of CS4398 DAC+CS8422, which is recognized by enthusiasts and becomes a landmark in the history of mobile phone Hi Fi;
Xplay upgrades the Qualcomm processor, adds OPA2604 operational amplifier, and improves the headphone driving force;
X3 replaced the audio scheme with ES9018 K2M, greatly reducing power consumption and simplifying the structure;
Xplay 3S adds OPA2604 operational amplifier chip on Xplay on the basis of X3;
Start from Xshot to customize the chip and establish the tuning style;
X5 joined Yamaha's YSS205X surround sound signal processing chip to open up the recording battlefield.
Vivo's Hi Fi history is just like the history of the application of abnormal chips in mobile phones. Its pursuit of sound quality has accumulated huge advantages in mobile phone Hi Fi. As its official micro blog said, three years ago, Vivo was concerned about whether the mobile phone Hi Fi was professional, but now they have begun to explore where the maximum of the mobile phone Hi Fi is.
