Apparatus and method for generating control signals for a loudspeaker system with spectral interlacing in the lower frequency range

An apparatus for generating control signals for a loudspeaker system with two sound generators, comprising:

• a first input configured for a first channel signal of a multi-channel audio signal;
• a second input configured for a second channel signal of the multi-channel audio signal;
• a first output configured for a first control signal for a first sound generator;
• a second output configured for a second control signal for a second sound generator;
• a base differential mode signal generator configured for forming a base differential mode signal from the first channel signal and the second channel signal;
• a differential mode signal generator configured for generating a first differential mode signal and a second differential mode signal from the base differential mode signal, wherein the first differential mode signal is phase-shifted with respect to the second differential mode signal;
• and
• a mixer configured for mixing a common mode signal with the first differential mode signal so as to acquire the first control signal, and for mixing the common mode signal with the second differential mode signal so as to acquire the second control signal,
• wherein the differential mode signal generator comprises:
• a frequency filter configured for receiving the base differential mode signal as one input signal or configured for receiving a first phase shifted signal and a second phase shifted signal derived from the base differential mode signal as several input signals and configured for generating one low-pass signal or several low-pass signals from the one input signal or the several input signals received by the frequency filter;
• and
• a spectral interlacer configured for spectrally filtering the one low-pass signal or a first low-pass signal of the several low-pass signals in a first manner so as to acquire a first filtered signal, and configured for spectrally filtering the one low-pass signal or a second low-pass signal of the several low-pass signals in a second manner so as to acquire a second filtered signal that differs from the first filtered signal, and
• wherein the differential mode signal generator is configured to use the first filtered signal as the first differential mode signal or to derive the first differential mode signal from the first filtered signal, or wherein the differential mode signal generator is configured to use the second filtered signal as the second differential mode signal or to derive the second differential mode signal from the second filtered signal.