Apparatus and method for mapping first and second input channels to at least one output channel

An apparatus for mapping a first input loudspeaker channel and a second input loudspeaker channel of an input loudspeaker channel configuration to at least one output loudspeaker channel of an output loudspeaker channel configuration, wherein each of the first and second input loudspeaker channels has a loudspeaker location direction in relative to a central listener position and the output loudspeaker channel has a loudspeaker location direction relative to the central listener position, wherein the first and second input loudspeaker channels comprise different elevation angles relative to a horizontal listener plane, the apparatus comprising:

• a processor to
• receive the first input loudspeaker channel and the second input loudspeaker channel;
• map the first input loudspeaker channel to a first output loudspeaker channel of the output loudspeaker channel configuration;
• map the second input loudspeaker channel to the first output loudspeaker channel, comprising processing the second input loudspeaker channel by applying an equalization filter to the second input loudspeaker channel to preserve spatial diversity of the first and second input loudspeaker channels;
• and
• output the first output loudspeaker channel,
• wherein the processor is implemented in hardware as a microprocessor, a programmable computer, an electronic circuit or a programmable logic device,
• wherein mapping the first input loudspeaker channel and the second input loudspeaker channel to the first output loudspeaker channel comprises combining the first input loudspeaker channel and the processed second input loudspeaker channel to the first output loudspeaker channel.