Emperor Ultimate Rack Technology

ActiveVibeControl eliminates sound-influencing vibrations by using piezoceramic elements in the component shelves of the EMPEROR rack system. Developed by Fraunhofer LBF in Darmstadt, Germany, and used exclusively by finite elemente in the audio furniture field, this technology offers optimum installation conditions for high-quality audio components.
The active vibration reduction is based on adaptronic elements that identify vibrations and counteract these in a controlled fashion by introducing a counter-vibration. This is possible using piezoceramic elements integrated into the component shelves and used there both sensorially and operatively. As sensory elements they detect sound-influencing vibrations that are signalled to a control unit, where the interference is evaluated and a signal is computed for active attenuation. This signal is sent to the piezoceramic element and compled into the component shelf. This causes specific counteraction to the vibration. In this way efficient attenuation or eradication of vibrations can be achieved by the active element (Fig. 1).

The optimum effect of the ActiveVibeControl technology is based on ALPORAS® aluminium foam for the component shelving in sandwich design. Outstanding homogeneity and extremely low weight combined with high specific rigidity and excellent energy absorption are the major features of this high-tech material. Stateof- the-art laser-measuring technology allows exact identification of problematic frequency modes within the component shelves and the corresponding positioning of the piezoceramic elements. Up to 10 dB vibration reduction can be achieved, for example with the component shelf of the 1250 Series (Figs. 2 and 3).

Fig. 1:
Principle of functioning Active vibration reduction / Shape control 













Active vibration and noise reduction    Active shape control
                                                    (Alteration of shape)

Fig. 2:
Vibration reduction using piezoceramic elements 













Fig. 3:
Identification of modes / Application of piezoceramic elements
(i.e. component shelf of serie





















ALPORAS® aluminium foam for component shelving in sandwich design
The ALPORAS® foam has an open pore cell surface with the individual cell closed.