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Features of SFR Components

Sound Field Restoration (SFR) is a high-quality audio system that can accurately restore the environmental sound of the original recording site. Its music playback will no longer rely on the reverberation in the audio room to create ambient sound, and it will be able to make the listener feel as if they are in a real music performance scene.

The idea and technology behind Sound Field Restoration (SFR) comes from my background as an audio enthusiast and a technical engineer. Based on over 20 years of research on the science behind audio technology, I developed the SFR audio system to have highest level of audio restoration on the market.


The system is composed of Heaven 1.0, Earth 1.0, Human 1.0, B&W Nautilus 801, and WRT Cable. How high is the sound quality of SFR? Imagine sitting right behind the conductor, listening to every note fresh from the VIP section.


Most audiophiles hope that their music playback can have the same sound effect as if they were in a music performance scene. Is it necessary to use all our equipment to achieve SFR effect? No, many of your existing equipment are still high-quality products. They fail to achieve the effect of being on-site, which may be caused by a certain device or even a certain cable.

How to use the least resources to achieve the effect you want? You must first evaluate the functional quality of the existing equipment. For operation, please refer to Functional Quality Assessment

Every audiophile has his own sound preference. As for which device is more suitable for their system, everyone will have their own considerations. Like the equipment on the market, our equipment has a positive effect but also has other negative effects. It should be noted that there is no best sound system, only the equipment that suits you best. Therefore, the product features we introduce below will include positive and negative (of course, these positive or negative may also be only from a certain perspective), so that you can choose the equipment correctly.

Our product's characteristic are the emphasis on timeliness. As a result, our equipment will have lower background noise, and can more truly show the music’s elegance, melodious, and vividness.

When time passes, some things may become meaningless. In other words, although certain things exist, but the timing is incorrect. This is a matter of timeliness. For other things, these outdated things are just invalid. But for music that is another matter. Musical electrical signals contain many frequency components. If they are not completely consistent in time, those components with incorrect time-effects will become noise---sound that should not appear at a certain point in time is noise. Therefore, real-time transmission and processing are very important for music electrical signals.

WRT Cable
The audio cable is a very special component. For a audio system with high resolution, you can find that the sound will have different emotional states with different cables. For the formation mechanism of this situation, please refer to the Particularity of Audio System.

Due to different configurations, each audio system may have its own characteristic sound. The effective use of cables will compensate for this to a certain degree, if you wish. For example, the heavier sound of a tube can be compensated with a Kimber cable. The heavier sound of transistor characteristics can be compensated by MIT cable. The thinner Hi-Fi sound can be compensated with Cardas cables, etc. Although, using compensation to solve the problem will not help or even reduce the micro dynamic density, it is also a way to improve the sound effect. WRT cables do not have this compensation effect.

Traditional audio cables have a common feature. They will each have their own sound characteristics. This self-characteristic will bring the cable's own rhythm to the music being played. This is the inevitable result of the lack of neutrality. This result destroys the unique qualities of music: freedom and openness. This is why the sound of music playing in the audio system is always so mechanical. No matter how valuable the audio system is, it is not immune to this result.

The same technology used in our E-100 amplifier has been developed into WRT Cable. Different from traditional audio cables, WRT Cable is produced based on circuit principles and using our DPEC technology. It is a transmission line circuit that transmits broadband music electrical signals in real time.

The WRT cable solves the most critical problem of the current audio system. In addition to maintaining the linearity and micro dynamic density of the audio system, the real-time spectrum effect can also prevent part of the music signal from becoming background noise after being transmitted through the cable. After using WRT Cable, immediately reduce the music background noise. The more instruments you play, the greater the noise reduction effect. The music is no longer as turbid and noisy as before. Whether it is a tube equipment or a transistor equipment, WRT Cable can comprehensively improve the sound quality of music playback.

Power Amplifier
The biggest feature of our power amplifier is to solve the "dynamic nonlinear expansion" distortion. Our research has found that after the amplifier is connected to the speaker, there will be an interaction between the two and cause this distortion. This distortion enhances the acoustic resonance of the audio room and the box sound of the speakers.

After the speaker is placed in the room, the speaker and the room together form a new frequency response characteristic. This distortion will dynamically change this new frequency response characteristic. Moreover, the sensitivity of the speaker will also vary non-linearly in response to frequency and sound pressure. In layman's terms, the sensitivity of the sound produced by the speaker will be different for different frequency voltages, and the sensitivity will also change non-linearly with the intensity of the sound pressure. This distortion causes the playback device to produce a variety of sounds with audio tags.

This situation increases the difficulty of setting up the audio system, and causes the playback sound pressure of the audio system to be limited to only a small area in order to maintain a satisfactory sound effect.

Our amplifier solves the problem of nonlinear dynamic expansion. After the amplifier is connected to the speaker, the linearity can be maintained close to the full power output. In other words, you don't need to expand the amplifier's power headroom by 5 to 10 times to maintain linearity. For example, if the maximum output of your music playback is 100 watts, you do not need to prepare 500 to 1000 watt amplifiers.

Like WRT cables, another characteristic of our amplifiers is accuracy. This requires reducing micro-dynamic filtering and broadening the frequency band of signal processing. The negative impact brought about by this is that defects in cables, preamplifiers, sources, and other equipment will be revealed. At present, the biggest problem in audio systems is the cable‘s sound state distortion. To use our amplifier, you may need to use our WRT cable at the same time. Cardas Golden Cross is not bad either. We have been using it before there was a WRT cable, but the sound is thicker and the micro dynamic density is weaker and there is some rhythm.

Perfect control performance is another characteristic of our amplifier. The working principle of the loudspeaker is like a linear motor, and its stroke needs to be effectively controlled in order to have an accurate sound. If the amplifier has good control performance, the inertial vibration of the speaker due to loss of control will disappear. The result is that the false low frequency that you are familiar with will disappear (this low frequency is not originally in the signal), in exchange for a controlled and clear low frequency, and a modulated low frequency formed by modulation of the amplitude (this modulated low frequency is reflected in the Layers of sound waves, the vibrating of a certain note of an instrument, the vibration of the singer’s cavity, etc.).

Very low noise is a common feature of our equipment, which includes music background noise. We compared more than ten systems by replacement, and E-100 significantly reduced the background noise of music. The electrical noise is significantly smaller. With the SFR playback system composed of the devices listed above, we put our ears close to the speaker at a distance of 1 inch and still did not hear any electrical noise (at any volume).

Many audiophiles will pay attention to whether the acoustic characteristics of the amplifier are transistors or tubes. If you ask what kind of acoustic characteristics our amplifiers belong to, I cannot answer this question. The sound of the SFR playback system is like being at the scene, and controlling the volume is like controlling the distance between us and the band. If we say that its sound effects are better than live, this is not an exaggeration, because we have no chance to sit in the conductor's position when listening to music live. The loyalty to the original signal is what our amplifier possesses. Audio critic Jimmy Saxon has a comment on the E-100 power amplifier at CES 2008.

Our amplifier does not modify the music signal. The amplifier will output whatever the signal source provides. You can only get the sound effects you want from the signal source or preamplifier.

The core part of the amplifier uses our DPEC technology to adjust the accuracy of broadband real-time processing, and is cured to improve long-term stability.

If used for SFR quality music playback, E-100 is suitable for driving speakers with a foam ring woofer of 12 inches and below, or a speaker with rubber ring 8 inches and below. If SFR quality is not required, the driving performance of E-100 is better than most high-end amplifiers on the market.

Heaven 1.0 is designed to effectively drive Nautilus 801. Therefore, it can drive all kinds of speakers with a woofer of 15 inches and below on the market, and its accuracy after being matched with the speakers is better than other existing devices with the same function on the market.

D/A Converter
Earth 1.0 is an extremely accurate audio CD digital/analog converter. The analog units including I/V conversion completely abandon the integrated circuit. There are 7 sets of power circuits that mimic batteries to supply power to each unit. Each analog unit uses our DPEC technology to adjust the accuracy of wideband real-time processing, and solidify to improve long-term stability.

Like our other equipment, in order to maintain linear phase, the analog filter of Earth 1.0 only maintains weak micro-dynamic filtering. The advantage is that the detail density of music playback is higher. The disadvantage is that it requires precise CD Transport to cooperate.

When the data read by CD Transport has more errors or there are more errors in the check data, the signal after D/A conversion may contain more digital components with lower frequencies. This requires an analog filter with a lower cut-off frequency point (with strong micro-dynamic filtering) to match this situation. Otherwise, the analog signal output will contain more digital components. Therefore, the weak dynamic filtering D/AC will require a precise CD Transport cooperation.

CD Transport
In an audio system with high analytical capabilities, audiophiles can easily find that there are differences in the sound quality of CD discs produced by different factories in the same version. Human1.0 CDTransport has extremely high accuracy, which can reduce this difference.

In the audio system, the CD player is the most sensitive equipment to external interference, especially the high-precision CD Transport. Human1.0 is the equipment we spend the most time on perfecting. At present, Human1.0 is still undergoing anti-interference operational testing.

We hope that our equipment is of high quality, high reliability and high stability. Therefore, before each type of equipment is put on the market, we have to carry out actual operation tests for many years. These tests also include combined use with other companies' products. For example, E-100 at the CES2008 audio exhibition. In this way, we find out the problem in actual use, even if this problem is only possible.

The obsession of audiophiles may be difficult for outsiders to understand. However, it is this obsession that promotes the technological development of the audio industry and ultimately benefits the public. SFR was born from our group of audiophiles' perseverance and pickiness on sound quality.

Created by Chen
Date: May-2021


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