1: A truly full frequency band designed speaker:

Generally, the audible range of human ears is designed between 20 to 20000Hz. In this frequency band, it also includes the frequency bands that most of musical instruments play. RASA is a pair of truly full range speakers, which only a few speakers can reach. Its average efficiency is 85.2B between 27 to 25000Hz, and its efficiency can reach to 83.5dB even in an extremely low frequency. It truly reach the capability of full frequency band of 20 to 20000Hz, +/- 3dB.

2: The design of low- resonance box:

About the structure of the box, RASA adopts premium high rigidity of finnish birch plywoods, and a sheet combined with high-temperature glue of boards which thickness is up to 42mm. This kind of boards have characteristics of high rigidity and high quality. Because of the adoption of different density of materials, the resonant frequency of the box can reach the maximum extent of absorption and dispersion. In addition, the adoption of non-parallel surface design makes the box unprecedented.

3: The adjustable phase and tweeter suspension shock-absorbing structure: M.S.D.S

RASA developed a new type of suspension structure in tweeter , and the characteristics of the structure are as follow:

a. Increases in the overall quality and balance of gravity of a tweeter

b. A custom-made rubber ring which is made of Teflon rubber and features highly vibration-absorption and highly internal resistance

c. Adjustable phase of the whole tweeter structure

Under the effect of this tweeter structure, the distortion of frequency band transition can be decreased to 10Hz. The distortion of the phase caused by the tweeter displacement is also decreased to zero. On the other hand, reflecting to the actual hearing, it will make the amount of information particularly richer, and the sounds of the musical instruments will also clearer. It’s obvious that the sound of field is more stability.

 The design of speaker box. What's matter is the mutual coupling of woofer, the volume of speaker and wavelength. And the most important part is the control of box vibration.

When we set the volume of speaker, we need to notice that if it is a square box, and then pay attention to the frequency resonance caused by parallel planes inside the box (also known as standing wave). The most perfect proportion is 0.618:1.618. It has the lowest resonance of wavelength under this golden ratio.

But in practices, especially under aesthetic requirements. It is very hard to achieve this ratio. Therefore, it is usually required that the lengths of the three sides of the box are indivisible by each other (including mutual back except not as X. 5). Thus, even if the interference of wavelength resonance caused by parallel planes cannot be excluded, it still effectively suppresses the interference of resonance wavelength caused by parallel planes. The best way is to use non-parallel planes and appropriate structural reinforcement to form the speaker box. In this way, resonance can be the lowest, but the cost will be the highest.

 Generally, the lower box vibration the better settings we have. This is a right orientation, but not the only way. In the design of speaker, there is nothing more than controlling the variable of vibration. Minimize the variable of box vibration can make you be able to request and control other variables more clearly. As we said, this is not the only way. Just like the bass reflex tube we used, the vibration of the box can also able to fine-tuning the tone. As early AR-3a, without calculation, the low frequency infection cannot be as excellent as it(of course match with the products of that time ). A box that controls it’s own vibration frequency is easier to create acoustic satisfaction than a box with low vibration. It’s suitable to use the speakers above bookshelf. Large speaker will make the box produce very strong harmonics because it’s resonance energy is enormous. Therefore, the solid and low-resonance type of box is necessary.

 Regarding the suspension structure of the tweeter. Basically, the tweeters are fix on the box directly.

In this way, the tweeter must be directly interfered by the vibration of the box, then intermodulation distortion will occur. Described by following numbers. The speed of sound in air at room temperature is about 340m/sec. Under the frequency of 20000Hz, the wavelength will be 0.017 meter. A full wavelength is 360 degrees. 1mm displacement will generate 21.1degrees phase difference. What an astonishing figure.

You might say “I can’t hear anything under 20000Hz.”. But remember, it also has 10.5degrees phase difference under 10000Hz. Moreover, the displacement of many boxes under high-volume vibration is not only 1 mm. And the resulting displacement is also nonlinear. So the complexity is unimaginable. This even hasn’t take account of the effect of the ringing phenomenon generated by the resonance frequency of the box. So the isolation shock absorber of the tweeter is highly desirable. Unless your box will not resonate and the quality is great.

 On the way to solve this problem, our predecessors made a lot of solutions. For example, put the tweeter in another independent box. This is a good way to isolate the bass resonance frequency. But if still put on the bass box. Then there will inevitably have the problem of following the displacement of the subwoofer.

 DIVINI patent of M.S.D.S tweeter suspension structure, adopting high-damping suspension structure, also a tweeter structure countered weight, can efficiently inhibit the distortion caused by the phenomenon of resonance and displacement. Because of the interference generated by the distortion and the reduction of virtual work, the timbre extend smoothly, and is full of energy. It can convey the atmosphere of the music more completely.

 RASA is the most high-standard and most reasonable structure of DIVINI AUDIO. In up to three years of testing, it resulted into an exceptional product. We are confident that it can bring you the highest quality of musical performance , and also waiting for your appreciation.