Downmixer and method for downmixing at least two channels and multichannel encoder and multichannel decoder

A method for downmixing at least two channels of a multichannel signal comprising two or more channels, comprising:

• calculating a partial downmix signal from the at least two channels using adding the two or more channels;
• calculating a complementary signal from the multichannel signal, the complementary signal being different from the partial downmix signal;
• and
• adding the partial downmix signal and the complementary signal to acquire a downmix signal of the multichannel signal.

A non-transitory digital storage medium having a computer program stored thereon to perform the method for downmixing at least two channels of a multichannel signal comprising two or more channels, comprising:

• calculating a partial downmix signal from the at least two channels using adding the two or more channels;
• calculating a complementary signal from the multichannel signal, the complementary signal being different from the partial downmix signal;
• and
• adding the partial downmix signal and the complementary signal to acquire a downmix signal of the multichannel signal,
• when said computer program is run by a computer.