Abstract: A method for an automatic equalization of sound pressure levels in at least one listening location, where the sound pressure is generated by a first and at least a second loudspeaker, comprising supplying an audio signal of a programmable frequency to each loudspeaker, where the audio signal supplied to the second loudspeaker is phase-shifted by a programmable phase shift relative to the audio signal supplied to the first loudspeaker, and where the phase shifts of the audio signals supplied to the other loudspeakers thereby are initially zero or constant; measuring the sound pressure level at each listening location for different phase shifts and for different frequencies; providing a cost function dependent on the sound pressure level; and searching a frequency dependent optimal phase shift that yields an extremum of the cost function, thus obtaining a phase function representing the optimal phase shift as a function of frequency.

Abstract: The invention relates to a method for automated tuning of a sound system, the sound system comprising delay lines, equalizing filters, and at least two loudspeakers, the method comprising the steps of reproducing a useful sound signal through the loudspeakers, measuring sound pressure values at least one location, providing a target transfer function for tuning the delay lines and the equalizing filters of the sound system, the target transfer function representing a desired transfer characteristics of the sound system, adjusting the delay of the delay lines, and adjusting amplitude responses of the equalizing filters such, that the actual transfer characteristics of the sound system approximates the target function.

Abstract: A Method for adjusting a sound system to a target sound, wherein the sound system having at least two groups of loudspeakers supplied with electrical sound signals to be converted into acoustical sound signals; said method comprising the steps of: sequentially supplying each group with the respective electrical sound signal; sequentially assessing the deviation of the acoustical sound signal from the target sound for each group of loudspeakers; and adjusting at least two groups of loudspeakers to a minimum deviation from the target sound by equalizing the respective electrical sound signals supplied to said groups of loudspeakers.

Abstract: In order to stabilize conical loudspeakers, it is recommended according to the present invention that the underside (20) of the membrane (12) be joined by means of a stabilizing element (19) joined to the moving coil carrier (14). This triangular structure alone results in sufficient stabilization of the membrane. If, in addition, the underside (20) of the membrane (12) is supported by the stabilizing element (19) at a point at which the first radial oscillation mode occurs, premature decoupling of the outer regions of the membrane is prevented.